Novel dialkyl vinyl ether phosphonate monomers: Their synthesis and alternated radical copolymerizations with electron-accepting monomers

Article abstract of DOI:10.1002/pola.26020

Three new vinyl ether monomers containing phosphonate moieties were synthesized from transetherification reaction. We showed that the yield was dependent on the spacer length between the vinyl oxy group and the phosphonate moieties: when the spacer is a single methylene side reaction may occur, leading to the formation of acetal compounds. Free-radical copolymerizations of phosphonate-containing vinyl ether monomers with maleic anhydride were carried out, leading to alternated copolymers of rather low molecular weights (from 1000 to 7000 g/mol). Both gel permeation chromatography and ³¹P NMR analyses enhanced possible intramolecular transfer reactions occurring from the phosphonate moieties. Kinetic investigation showed that the electron-withdrawing character of the phosphonate moieties tends to decrease the rate of copolymerization. Nevertheless, almost complete monomers conversion was reached after 30 min of reaction with dimethyl vinyloxyethylphosphonate (VEC ₂PMe). Then, radical copolymerization of VEC₂PMe with a series of electron-accepting monomers, that is, dibutyl maleate, dibutylitaconate, itaconic anhydride, butyl maleimide, and methyl maleimide, led to a series of alternated copolymers. From kinetic investigation, we showed that the higher the electron-accepting effect, the faster the vinyl ether consumption and the higher the molecular weights.

Full text of DOI:10.1002/pola.26020

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Novel Dialkyl Vinyl Ether Phosphonate Monomers: Their Synthesis and
Alternated Radical Copolymerizations with Electron-Accepting Monomers
1
1
1
Fadela Iftene,1,2 Ghislain David, Bernard Boutevin, Remi Auvergne,
ꢀ
Ali Alaaeddine,1 Rachid Meghabar2
1
ꢀ
Institut Charles Gerhardt UMR 5253, IAM, Rue de l’ecole normale, 34296 Montpellier, Cedex 5, France
2
ꢀ
Laboratoire de Chimie des Polyme`res, Universite d’oran, BP 1524 El’Mnaouer, Oran 31000, Algeria
Correspondence to: G. David (E-mail: ghislain.david@enscm.fr)
Received 27 January 2012; accepted 23 February 2012; published online
DOI: 10.1002/pola.26020
ABSTRACT: Three new vinyl ether monomers containing phospho-
nate moieties were synthesized from transetherification reaction.
We showed that the yield was dependent on the spacer length
between the vinyl oxy group and the phosphonate moieties: when
the spacer is a single methylene side reaction may occur, leading
to the formation of acetal compounds. Free-radical copolymeriza-
tions of phosphonate-containing vinyl ether monomers with
maleic anhydride were carried out, leading to alternated copoly-
mers of rather low molecular weights (from 1000 to 7000 g/mol).
Both gel permeation chromatography and 31P NMR analyses
enhanced possible intramolecular transfer reactions occurring
from the phosphonate moieties. Kinetic investigation showed that
the electron-withdrawing character of the phosphonate moieties
tends to decrease the rate of copolymerization. Nevertheless,
almost complete monomers conversion was reached after 30 min
of reaction with dimethyl vinyloxyethylphosphonate (VEC2PMe).
Then, radical copolymerization of VEC2PMe with a series of elec-
tron-accepting monomers, that is, dibutyl maleate, dibutylitaco-
nate, itaconic anhydride, butyl maleimide, and methyl maleimide,
led to a series of alternated copolymers. From kinetic investiga-
tion, we showed that the higher the electron-accepting effect, the
faster the vinyl ether consumption and the higher the molecular
C
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weights. 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym
Chem 000: 000–000, 2012
KEYWORDS: alternating copolymers; copolymerization; FTIR;
heterogeneous polymers; kinetic; molecular weight; phosphonate
vinyl ether
INTRODUCTION Phosphorus-containing polymers functional-
ized either at the main chain (e.g., polyphosphazene and
polyphosphoesters) or at the side chain found applications
in many fields. Dental adhesives, ion-exchange resins, and
flame retardants are just some of the more common applica-
tions.1–4 Compounds containing phosphorus are also
excellent promoters with respect to adhesion,5–9 and thus
anticorrosion. Only few phosphorus-containing monomers
are so far commercially available, and most of them are
phosphate-type monomers.10,11 Recently, we have published
a reviewing paper12 gathering the syntheses and radical
(co)polymerizations of phosphonate-containing vinyl mono-
mers, ranging from allyl-type to (meth)acrylic-type mono-
mers. This article shows that the phosphonate group weakly
changes the double bond reactivity, despite its electron-
donating character with the exception of p-benzyl phospho-
nate monomers, where the phosphonate group enhances the
reactivity of the styryl monomer in free-radical polymeriza-
tion.13 Considering specifically both phosphonate allyl-type
and vinyl-type monomers, we showed that their radical
homopolymerization led to oligomers with expected poor
yields.14,15 In contrast, their radical copolymerization with
electron-accepting monomers was deeply investigated. For
instance, radical copolymerization of diethyl vinyl phospho-
nate (DEVP) with styrene carried out at 100 ꢀC resulted in
copolymers of high molecular weight values;16 the incor-
poration of DEVP units lowered the Tg value of polystyrene
due to the steric hindrance of phosphonate group. In this
article, we focus on dialkyl vinyl ether phosphonate mono-
mers. Vinyl ether monomers are good candidates to reach
high molecular weights polymers either by cationic homo-
polymerization17 or by radical copolymerization18,19 (when
associated to an electron-accepting monomer). To the
author’s knowledge, only Kohli et al.20–22 performed the
radical copolymerization of diisopropyl 2-vinyloxyethyl-
phosphonate with a series of maleimide monomers to mod-
ify selective surfaces.
We develop herein the synthesis through transetherification
of a series of novel dialkyl vinyl ether phosphonate mono-
mers as well as their radical copolymerization with a series
of electron-accepting monomer.
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SCHEME 1 Synthetic pathway to provide dialkyl vinyl ether phosphonate monomers.
RESULTS AND DISCUSSION
We can note that the final yields, obtained after purification
by column, are rather low (about 30%) and do not vary
with the R group. Nevertheless, with two methylene spacers,
the final yield is increased up to 80%. This behavior was
ascribed to the acetal formation during the transetherifica-
tion reaction. Indeed, the 31P NMR (Fig. 1) of VEC2PMe
crude product reveals the presence of two acetal com-
pounds: tetramethyl((ethane-1,1-diylbis(oxy))bis(ethane-2,1-
diyl))bisphosphonate in high yield and dimethyl(2-(1ethoxye-
thoxy)ethyl)phosphonate in lower yield. The 31P NMR of the
crude also shows the unreacted hydroxyl compound as well
as the expected vinyl ether monomer.
Synthesis of Dialkyl Vinyl Ether Phosphonate Monomers
Several attempts were made to efficiently perform the syn-
thesis of dialkyl vinyl ether phosphonate monomers. The
first ones were made through the Arbusov reaction by reac-
tion of chloro ethyl vinylether with triethylphosphite.23
Diethyl vinyloxy phosphonate was obtained in good yield;
however, ethyl diethylphosphonate is always obtained in
non-negligible amounts, despite drastic reaction conditions.
More interestingly, transetherification reaction was also used
between hydroxyl compound and vinyl ether. Transetherifica-
tion efficiently occurs when catalyzed by mercury or palla-
dium salts.24–26 Furthermore, acetals may be also formed,
depending on both the efficiency and the stability of the cat-
alyst. The rather complex mechanism of transetherification,
catalyzed by palladium salts, was recently discussed by
Muzart.27 Despite the expected catalyst complexation from
phosphorus, we have investigated this reaction to obtain a
series of novel dialkyl vinyl ether phosphonate monomers.
The synthetic strategy, given in Scheme 1, is based on a two-
step reaction.
Despite the presence of 1,10-phenantrolin, acetals were
formed, which demonstrates the negative effect of phospho-
rus complexation toward the catalyst. We decreased the tem-
perature down to ambient temperature to lower the amount
of acetals. Nevertheless, column purification with dichloro-
methane/ethyl acetate as eluent was required and vinyl
ether monomers were obtained with high purity. Figure 2
1
shows both the 31P and H NMR of VEC2PMe.
The first one is the synthesis of phosphonate-containing
hydroxyl compounds from dialkyl phosphite. The reaction of
dialkyl phosphite with paraformaldehyde leads to phospho-
nate-containing primary alcohol with one methylene spacer in
between.28 Furthermore, the radical addition of dialkylphos-
phite onto vinyl acetate, followed by the acetate group cleav-
age in basic medium, leads to phosphonate-containing pri-
mary alcohol with two methylene spacers in between.29,30
This first-step reaction was already deeply described in other
papers and leads to alcohols with good yields and high purity.
The second-step reaction is the transetherification reaction
between ethyl vinyl ether and phosphonate-containing
primary alcohols in the presence of palladium catalyst and
1,10-phenantrolin, which is expected to avoid the formation of
acetal side products. This synthetic strategy allowed perform-
ing the synthesis of four different phosphonate-containing
vinyl ethers, noted VECxPR, by varying both the spacer length
x and the R group of the phosphonate moieties (Table 1).
TABLE 1 Yield and 31P NMR for New Phosphonate-Containing
Vinyl Ether Monomers
31P NMR
Chemical
Monomer
VEC1PMe
Structure
Yield (%)
20
Shift
22.00
VEC1PEt
30
85
19.69
30.57
VEC2PMe
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FIGURE 1 31P NMR spectrum of the crude product for the reaction between ethyl vinyl ether and phosphonate-containing primary
alcohol.
The 31P NMR shows a single peak centered at 30.57 ppm,
characterizing the phosphonate moieties of the monomer.
izing effects are similar for both monomers (i.e., values of
Q very close), then the polymerization will turn into alter-
nated radical copolymerization. Besides, if two monomers
show opposite values for e parameter, then expected alter-
nated copolymer should be also obtained. According to the
literature,31–33 vinyl ether monomers usually exhibit negative
values for e parameter, which enhances the electron-donating
character of allyl monomers. Maleic anhydride (MA)34–36
shows positive e value of about 2.3. Furthermore, MA and
vinyl ethers show Q values of about 0.2 and 0.1, respectively
(0.1 is an average value as the Q value of the vinyl ethers
may vary with the substituent). Thus, the Alfrey–Price
parameters of vinyl ethers and MA clearly support behavior
of alternated radical copolymerization. Furthermore, Fuji-
mori37 performed a kinetic investigation of the radical
copolymerization between MA and isobutyl vinyl ether and
stated on the formation of charge transfer complex (CTC)
with a complexation constant value of 0.033 L/mol. The for-
mation of the CTC enhances the formation of alternated
structure. Hao et al.38 also showed that the cis-conformation
of MA was obtained in the copolymer, due to the CTC forma-
tion and participation to the radical polymerization.
1
From H NMR, the vinyl protons are clearly identified at 6.4,
4.2, and 4.06 ppm. The OCH2 methylene group shows a peak
centered at 3.88 ppm as triplet of doublets. Similarly, the sig-
nal of CH2P methylene group appears at 2.2 ppm as a triplet
of doublets due to the a-position of the phosphorus atom.
Finally, the signal of the methyl groups for phosphonate moi-
eties is clearly identified as a doublet at 3.75 ppm. Figure 3
1
shows both the 31P and H NMR of VEC1PEt. A single peak is
also observed from 31P NMR centered at 19.69 ppm. This sig-
nal is downshifted, compared with that of dimethyl vinyloxye-
thylphosphonate (VEC2PMe), as the phosphonate moieties is
situated in b-position of the vinyl-oxy group. From 1H NMR,
we can especially observe the signal at 3.9 ppm of the methyl-
ene CH2P that appears as a doublet.
Radical Copolymerization of Dialkyl Vinyl Ether
Phosphonate Monomers with Maleic Anhydride
Vinyl ether monomers are good electron-donating mono-
mers, and their radical copolymerizations with electron-
accepting monomers mainly afford alternated copolymers.
The capability of monomers to efficiently copolymerize is
connected to both their polarizing effect and their ability to
accept/give electrons. These Alfrey–Price parameters, noted
Q (for polarizing effect) and e (for the ability to give/accept
electrons), must be known to estimate the copolymer struc-
tures, that is, statistical or alternated structures. If the polar-
Hence, in this study, the radical copolymerizations of dialkyl
vinyl ether phosphonate monomers were investigated with
MA as electron-accepting monomer to perform alternated
copolymers bearing phosphonate moieties (Scheme 2). For
each radical copolymerization, the reaction conditions were
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FIGURE 2 31P and 1H NMR spectra of VEC2PMe.
the following: chloroform as solvent with a molar ratio
concentration S0 of 4 (S0 ¼ [solvent]0/[monomers]0), 2,20-
azobis(isobutyronitrile) (AIBN) as initiator with a molar ratio
concentration C0 of 0.05 (C0 ¼ [initiator]0/[monomers]0). All
radical copolymerizations were carried out at 70 ꢀC with a
MA/vinyl ether monomer molar ratio of 1/1.
Quantitative conversion for both MA and vinyl ethers was
observed after 24 h. Three alternated copolymers were
synthesized (Scheme 2) and purified from diethyl ether pre-
cipitation. As an example, Figure 4 shows the 13C NMR of
poly(VEC2PMe-alt-MA) and proves the good purity of the
obtained copolymers.
FIGURE 3 31P and 1H NMR spectra of VEC1PEt.
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SCHEME 2 Radical copolymerizations of MA with a series of phosphonate-containing vinyl ethers.
The 31P NMR shows a single peak shifted at 31 ppm. Similar
result was obtained for poly(VEC1PMe-alt-MA), where a sin-
gle peak was also obtained at 26 ppm from 31P NMR. When
radical copolymerization is carried out with VEC1PEt, two
peaks are nevertheless observed from 31P NMR (Fig. 5): a
broad peak at 18.6 ppm characterizes the phosphonate moi-
eties of poly(VEC1PEt-alt-MA), whereas the second peak at
15 ppm enhances possible side reaction.
39
€
Bingol et al. have demonstrated, especially by means of elec-
trospray ionization-mass spectroscopy, that polymerization of
FIGURE 4 13C NMR spectrum of poly(VEC2PMe-alt-MA).
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FIGURE 5 31P NMR spectrum of VEC1PEt and poly(VEC1PEt-alt-MA).
vinyl phosphonate is mainly dominated by transfer reaction;
the predominant transfer occurs by intramolecular hydrogen
transfer of phosphonate ester groups, which in consequence
creates a PAOAC bond in the main chain. Nevertheless,
these authors mentioned that this reaction was predominant
mainly with isopropyl as alkyl group (Scheme 3, reaction 1),
thus leading to a tertiary radical that promotes fast initia-
tion. Shulyndin et al.40 proposed another mechanism also
based on radical transfer reaction (Scheme 3, reaction 2).
They claimed that intracyclization occurred between the
growing radical and the phosphonate moieties, leading to the
generation of an alkyl radical species and of the creation of
five-member cycle. As alternated copolymerization between
MA and phosphonate-bearing vinyl ethers is expected, it is
rather difficult to state on the mechanism leading to side
reaction.
Gel permeation chromatography (GPC) was also conducted on
different copolymers and molecular weight values were eval-
uated by using PMMA standards. GPC traces of copolymers
show shoulder in the low molecular weight region, especially
for poly(VEC1PEt-alt-MA) copolymer (Fig. 6). This shoulder
confirms the presence of side reactions by chain transfer reac-
tion, as mentioned above, leading to low molecular weight
oligomers. This shoulder is increased when the vinyl ether
alkyl group is ethyl group, which again confirms the previous
observed data (Fig. 5). The Mw values are rather low for poly
(VEC1PEt-alt-MA) and poly(VEC1PMe-alt-MA), about 900 and
SCHEME 3 Side reactions occurring by intramolecular transfer reaction.
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FIGURE 6 GPC traces of poly(VEC1PEt-alt-MA), poly(EVC1Me-alt-MA) copolymers (left), and poly(EVC1Me-alt-MA) copolymer (right).
1100 g/mol, respectively (Table 2). Poly(VEC2PMe-alt-MA)
shows higher Mw value of about 7000 g/mol.
character than the phosphonate moieties for a faster FAVE-8
copolymerization as compared to phosphonate-bearing VEs.
Thus, another factor has to be taken into account, relating to
phosphonate moieties acting as radical inhibitor. Indeed, phos-
phorus compounds are known to act as radical scavenger,
especially in the gas phase when used as flame retardant;41
furthermore, retardation is often observed during the con-
trolled radical polymerization of phosphonate-containing
monomers due to radical initiator inhibition.42 Finally, if the
polymerization rates for both VEC1PMe/MA and VEC2PMe/MA
copolymerizations are fairly similar, VEC2PMe reaches 100%
conversion after 30 min, whereas for VEC1PMe, the maximum
conversion is 78%. This result enhances the negative effect of
the spacer length: the lower the spacer length the higher the
electron-withdrawing effect of the phosphonate group.
No shoulder was observed from the GPC trace, which may
support that the spacer length has an influence on the chain
transfer reaction mechanism (Scheme 3).
Kinetic investigation of the radical copolymerizations was
carried out by means of Fourier Transform Infra Red (FTIR),
and especially by following the disappearance of the vinyl
ether double-bond characteristic vibration bands at 1623 and
1638 cmꢁ1. Thus, the vinyl ether consumption was plotted ver-
sus time (Fig. 7) for the radical copolymerizations of VEC1PMe/
MA and VEC2PMe/MA. For comparison, model radical copoly-
merizations of butyl vinyl ether (BVE) with MA and of 1H, 1H,
2H, 2H-perfluorodecyl vinyl ether (FAVE-8) with MA were also
followed by FTIR (Fig. 7).
Radical Copolymerization of VEC2PMe with a Series of
Electron-Accepting Monomers
As VEC2PMe provides both the higher Mw and monomer con-
version when copolymerized with MA, it was copolymerized
with a series of electron-accepting monomers, such as dibu-
tyl maleate (DBM), dibutylitaconate (DBI), itaconic anhydride
We can note that the rate of polymerization for phosphonate-
bearing VEs is generally lower than that of model systems.
This may be attributed first to the electron-withdrawing char-
acter of the phosphonate moieties. Nevertheless, the perfluoro-
decyl group of FAVE-8 shows a stronger electron-withdrawing
TABLE 2 Monomer Conversion and Molecular Weight of Copolymers Obtained by Radical Copolymerization of Phosphonate-
Bearing VE with Electron-Accepting Monomers
Copolymer
VE Conversiona
Comonomer Conversiona
Mw (g/mol)b
PDI
Poly(VEC1PMe-alt-MA)
Poly(VEC2PMe-alt-MA)
Poly(VEC1PEt-alt-MA)
Poly(VEC2PMe-alt-DBMA)
Poly(VEC2PMe-alt-DBI)
Poly(VEC2PMe-alt-IA)
Poly(VEC2PMe-alt-BM)
Poly(VEC2PMe-alt-MM)
0.99
0.98
0.97
0.65
0.74
0.90
0.97
0.98
0.98
0.98
0.85
0.70
0.93
0.93
0.99
0.90
1,100
7,000
900
1.10
1.06
1.10
1.54
1.25
1.24
1.69
1.90
4,600
3,200
1,700
3,100
5,000
a
b
Calculated from 1H NMR.
From GPC by using PMMA standards.
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FIGURE 7 Vinyl ether conversion versus time for the radical copolymerizations with MA.
(IA), butyl maleimide (BM), and methyl maleimide (MM)
(Scheme 4).
and the comonomer (i.e., electron-accepting monomer) is
close for each copolymerization, which may depict alternat-
ing copolymerization as VE does not homopolymerize.
Copolymers were purified by precipitation. As an example,
After 24 h reaction, conversion of monomers was deter-
mined from 1H NMR (Table 2). The conversion of VEC2PMe
SCHEME 4 Radical copolymerizations of VEC2PMe with a series of electron-accepting monomers.
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FIGURE 8 13C NMR spectrum of poly(VEC2PMe-alt-BM).
13C NMR (Fig. 8) of poly(VEC2PMe-alt-BM) is given to prove
the good purity of the obtained copolymers. The purified
copolymers were analyzed by means of GPC and Mw values
were obtained from PMMA standards (Table 2). The GPC
traces, given in Figure 9, do not show any shoulder in the
low molecular weight region, which is in agreement with the
result obtained from the copolymerization of VEC2PMe with
MA. Interestingly, we can also remark that both Mw and pol-
ydispersity index (PDI) values are dependent on the type of
electron-accepting monomer. Indeed electron-poor mono-
mers, such as MA or maleimides, lead to copolymers of
higher Mw and higher PDIs values. In contrary, monomers
showing a lower electron-accepting effect, such as dibutyl
itaconate or IA, lead to copolymers of low Mw and PDIs val-
ues. Furthermore, these monomers show a strong polarizing
effect unlike vinyl ether monomers. These opposite effects
are detrimental for efficient radical copolymerizations, as
expressed from the lower monomer conversions (Table 2).
Kinetic investigation of the radical copolymerizations of
VEC2PMe with the electron-accepting monomers was carried
out by means of FTIR and VE conversion was plotted versus
time (Fig. 10). This figure evidences the positive effect of
strong electron-accepting monomers on the polymerization
rate. Indeed, the higher the electron-accepting effect, the
faster the VE consumption, as expected. We can also observe
an inhibition period during the copolymerizations of
FIGURE 9 Molecular weight distribution of copolymers
FIGURE 10 VEC2PMe conversion versus time for the radical
obtained from radical copolymerization of VEC2PMe.
copolymerizations with a series of electron-accepting monomers.
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VEC2PMe with IA and dibutyl maleate (DBMA). Unexpectedly,
after this inhibition period, the VE consumption is very fast
with IA. Regarding the polarizing and electron-accepting
effects of IA, this result remains unexplained.
CH2-O), 16.33 (d, 2C, CH3). 31P NMR (162 MHz, CDCl3, d):
24,72.
Synthesis of Dimethyl-a-Hydroxyethylphosphonate
A mixture of 3.92 g (0.02 mol) 2-(dimethoxyphosphoryl)
ethyl acetate, (previously synthesized from telomerization of
vinylacetate with dimethyl phosphonate andꢁt4ert-amylperoxi-
pivalate at 70 ꢀC), KOH 3% (0.0672, 12.10 mol), and 20
mL of methanol was stirred at 60 ꢀC for 24 h. Dimethyl-a-
hydroxyethylphosphonate is obtained under high vacuum
with 90% yield.
EXPERIMENTAL
Materials
All the solvents and reagents (Sigma-Aldrich, Fluka or Unim-
atec) were used with a purity of 98–99%. Diethyl vinyl ether,
palladium(II)acetate, 1-10 phenanthroline, paraformaldehyde,
dimethyl phosphonate, diethyl phosphonate, diisopropyl
phosphonate, BVE, FAVE-8, tert-amylperoxipivalate, potas-
sium hydroxide, potassium carbonate, vinyl acetate, itaconate
anhydride, dibutyl itaconate, dibutyl maleate, methyl malei-
mide, and butyl maleimide were used without purification.
MA and AIBN were purified by recrystallization from
dichloromethane and methanol, respectively, and dried under
vacuum.
1H NMR (400 MHz, CDCl3, d), ppm: 4.36 (s, 1H, OH); 3.64
(td, H2,OACH2); 3.48 (d, H6, PO(OCH3)2); 1.84 (td, H2, CH2P).
31P NMR (162 MHz, CDCl3, d): 32.62.
Synthesis of Dialkyl Vinyl Ether Phosphonate
The dialkyl vinyl ether phosphonate was obtained from
transetherification of hydroxyl-alkylphosphonate.
For example, a solution of 1,10 phenanthrolin (0.210 g,
0.03 mol) in 15 mL of dichloromethane was added dropwise
to a flask already containing palladium acetate catalyst
(11.0 g, 5 mmol) in dichloromethane (15 mL). The reaction
mixture was left under magnetic stirring for 20 min to form
a complex. Then a mixture 6.1 g (0.04 mol) of dimethyl
2-hydroxyethylphosphonate, 28.05 g (0.4 mol) of ethyl vinyl
ether, and 15mL of CH2Cl2 was added to the complex. The
reaction mixture was left under stirring at room temperature
during 48 h. Then the reaction mixture was filtered on celite
(dicalite 4158) to eliminate the complex and followed by
vacuum distillation to remove the excess of ethyl vinyl ether
and solvent. The crude product was purified by silica gel col-
umn chromatography by using a mixture of 20 acetate/80
CH2Cl2 to obtain a monomer as a colorless oil.
1H, 13C, 31P, and 19F NMR spectra were recorded in CDCl3, ace-
tone d6 solutions, dimethyl sulfoxide-d6, or MeOH-d4 (between
5 and 100 mg of each compound dissolved in 0.6 mL of
1
solvent) on a Bruker Avance 400 MHz spectrometer. H, 13C,
31P, and 19F chemical shifts are expressed in ppm/tetramethyl-
silane, ppm/H3PO4, and CFCl3 external standard, respectively.
All non-first-order spectra were calculated with g-NMR. Size
exclusion chromatography was performed on a Varian appara-
tus equipped with a RI Shodex refractive index detector. Two
ꢀ
PL-gel mix D columns were used at 70 C with a 0.8 mL/min
flow rate of DMF, calibrated using polymethylmethacrylate
ꢀ
standards, and two PL-gel mix C columns were used at 35 C
with 1 mL/min flow rate of THF, calibrated using polystyrene.
FTIR spectra were recorded on Nicolet 6700 FTIR spectrome-
ter coupled with thermo spectra tech.
1H NMR (400 MHz, CDCl3, d): 6.4 (q, 1H, CH), 4.06, and 4.22
(dd, 2H, H2C¼¼), 3.88 (td, 2H, OACH2), 1.84 (sd, 6H, CH3),
2.2 (td, 2H, CH2A). 13C NMR (400 MHz, CDCl3, d): 150.8 (s,
CH), 87.18 (s, H2C¼¼), 61.55(s, OACH2), 52.23 (s, CH3), 25.31
(d, CH2-P). 31P NMR (400 MHz, CDCl3, d): 30.57.
Monomers and Polymers Syntheses
Synthesis of Dialkyl-a-Hydroxymethylphosphonate
Dialkyl-a-hydroxyalkylphosphonate compounds were synthe-
sized from Pudovik reaction by reacting equimolar amounts of
dialkyl hydrogenophosphonate and paraformaldehyde in the
presence of anhydrous potassium carbonate and methanol at
room temperature.
Dimethyl Vinyloxymethylphosphonate
1H NMR (400 MHz, CDCl3, d): 6.4 (q, 1H, CH), 4.06 et 4.22
(dd, 2H, ¼¼CH2), 3.88 (td, 2H, CH2AP), 1.84 (sd, 6H, CH3).
13C NMR (400 MHz, CDCl3, d): 151 (d, 1C, CH), 87.8 (s,1C,
¼¼CH2), 59 and 61 (d, 1C, CH2-Pc), 52.8 (d, 2C, CH3). 31P
NMR (162 MHz, CDCl3, d): 22.
For example: 10 g (0.09 mol) of dimethyl hydrogenophosph-
onate, 2.73 g (0.09 mol) of paraformaldehyde, 30 mL of
methanol, and 0.62 g of anhydrous K2CO3 were introduced
in a two-necked flask. The solution was vigorously stirred
Diethyl Vinyloxymethylphosphonate
under methanol during
1 h. Dimethyl-a-hydroxymethyl-
1H NMR (400 MHz, CDCl3, d): 6.4 (q, 1H, CH), 4.06 et 4.22
(dd, 2H, ¼¼CH2), 3.88 (td, 2H, PACH2), 1.84 (sd, 6H, CH3).
13C NMR (400 MHz, CDCl3, d): 150 (d, 1C, CH), 88 (s, 1C,
¼¼CH2), 60, 62 (d, 1C, PACH2), 62 (s, 2C, OCH2), 16 (d, 2C,
CH3). 31P NMR (162 MHz, CDCl3, d): 19.69.
phosphonate is obtained under high vacuum with 98% yield.
1H NMR (400 MHz, CDCl3, d): 3.6 (d, 6H,PO(OCH3); 3.9 (d,
2H, CH2P); 5.3 (sl, 1H, OH). 31P NMR (CDCl3), 31P NMR (400
MHz, CDCl3, d): 28.2, 13C NMR (400 MHz, CDCl3): 56 (d, Cb),
53 (d, Cc).
Radical copolymerizations of dialkyl vinyl ether phosphonate
monomers with electron-accepting monomers.
Diethyl-a-Hydroxymethylphosphonate
1H NMR (400 MHz, CDCl3, d): 5.17 (sl, 1H, OH), 3.8 (d, 2H,
CH2AP), 4.1 (m, 4H, CH2AO), 1.24 (t, 6H, CH3). 13C NMR
(400 MHz, CDCl3, d): 56.55 (sd, 1C, CH2-P), 62.55 (d, 2C,
The copolymers were synthesized by reacting equimolar
amounts of vinyl ethers and MA, and of VEC2PMe with a series
of electron-accepting monomers (IA, DBM, DBI, MM, and BM).
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As an example, in a two-necked round-bottomed flask
equipped with a condenser, a solution of 2 g (1.11 ꢂ 10ꢁ2 mol)
of VEC2PMe and 1.09 g (1.11 ꢂ 10ꢁ2 mol) of MA, 3% (0.110 g)
of AIBN, and 7.15 mL of chloroform (S ¼ 4) was degassed for
OACH2, 2(OACH3), NACH3), 2.1–3.1 (2H, CH from succini-
mide ring). 13C NMR (400 MHz, d6-DMSO, d): 175–180 (2C,
C¼¼O) 21–29 (2C, PACH2, NACH3), 52 (2C, OACH3), 53–66
(4C, ACH2 ethyl group and CH succinimide ring), 70–78 (2C,
OACH and OACH2). 31P NMR (162 MHz, d6-DMSO, d): 31.2.
ꢀ
20 min with argon and then stirred at 70 C. After 20 h, poly
(VEC2PMe-alt-MA) was precipitated from diethyl ether.
Poly(VEC2PMe-alt-DBM)
1H NMR (400 MHz, d-CDCl3, d): 3.5–3.7 (6H, CH3), 1.9–2.2
(2H,CH2AP), 4.0–4.4 (2H, CH2AO), 2.2–3.1 (2H,CH, MA ring
and CHAO), 1.2–1.6 (2H, CH2 from ethyl group). 13C NMR
(400 MHz, d6-DMSO, d): 170–175 (2C, C¼¼O), 55–65 (3C, CH2
from ethyl group and CH of MA ring), 72–80 (2C, CH2AO
and CH from VEC2PMe), 52 (2C, CH3), 25(1C, PACH2). 31P
NMR (162 MHz, d6-DMSO, d): 24.72.
1H NMR (400 MHz, d-CHCl3, d): 0.7–1.0 (6H, CH3 from
DBM), 1.1–2.3 (12H, PACH2, CH2 from ethyl group, CH2
from DBM), 2.5–3.1(2H, CH), 3.1–4.4 (15H, OACH2, OACH,
and CH, OACH3). 13C NMR (400 MHz, d-CDCl3, d): 168–175
(2C, C¼¼O) 14–28 (4C, CH2 and CH3, PACH2), 52 (2C,
OACH3), 54–67 (3C, OACH2, OACH), 32–45 (4C, OACH and
OACH2). 31P NMR (162 MHz, d-CDCl3, d): 31.0.
Poly(VEC1PMe-alt-MA)
Poly(VEC2PMe-alt-DBI)
1H NMR (400 MHz, d4-CH3OH, d): 3.5–4.3(6H, CH3, OACH,
CH2AP), 1.9–2.2 (2H, CH2AP), 4.0–4.4 (2H, CH2AO), 2.5–2.9
(2H, CH, MA ring). 1.1–1.3 (2H, CH2 from ethyl group). 31P
NMR (162 MHz, d4-CH3OH, d): 26.
1H NMR (400 MHz, d-CHCl3, d): 0.7–1.0 (6H, CH3 from DBI),
1.7–2.4 (6H, PACH2, CH2 from ethyl group), 2.5–3.2 (3H, CH
CH2AC¼¼O), 3.5–4.2 (12H, OACH2, OACH3). 13C NMR (400
MHz, d-CDCl3, d): 165–175 (3C, CH2AC, C¼¼O) 12–21 (4C,
CH2 and CH3), 22–48 (6C, PACH2, CH2AC¼¼O, CH2), 53
(2C, OACH3,), 54–67 (4C, OACH2, OACH). 31P NMR (162
MHz, d-CDCl3, d): 31.0.
Poly(VEC1PEt-alt-MA)
1H NMR (400 MHz, d6-DMSO, d): 1–1.5(8H, CH3, CH2 from
ethyl group), 3.7 (2H,CH2AP), 3.9–4.3 (3H, OACH2, OACH),
2.5–2.9 (2H,CH, MA ring). 13C NMR (400 MHz, d6-DMSO, d):
170–175 (2C, C¼¼O) 52–65 (6C, CH2 from ethyl group and
CH of MA ring, OACH2AP and OACH from VEC2PMe), 15
(2C, CH3). 31P NMR (162 MHz, d6-DMSO, d): 18.5 and 15.
CONCLUSIONS
A series of three new vinyl ether monomers containing phos-
phonate moieties was developed from transetherification
reaction, in the presence of catalytic system, that is, palla-
dium acetate/phenanthrolin. Their radical copolymerizations
with MA afforded alternated copolymers, bearing phospho-
nate moieties. Unexpected intramolecular chain transfer
reactions, occurring from phosphonate moieties, led to low
molecular weight copolymers, depending on the spacer
length between the vinyl oxy group and the phosphonate
moieties. Finally, we developed a range of phosphonate-
containing alternated copolymers by free-radical copolymer-
ization of VEC2PMe with a series of electron-accepting
monomers, such as DBMA, DBI, IA, BM, and MM. From
kinetic investigation, we demonstrated the positive effect of
the strong electron-withdrawing effect of maleimide mono-
mers on both the molecular weight and the vinyl ether
conversion. Interestingly, fast rate of free-radical copolymer-
ization was observed when VEC2PMe was polymerized with
IA, a bio-based monomer. In conclusion, we were able to
provide a wide range of alternated copolymers bearing phos-
phonate moieties, these compounds may be investigated for
different applications such as anticorrosive coatings or even
as flame retardant.
Poly(BVE-alt-MA)
1H NMR (400 MHz, d6-acetone, d): 0.8 (3H, CH3 from BVE),
1.2–1.7 (6H, ACH2 and CH2 from ethyl group), 1.8–2.6 (2H,
ACH, 2.8–4.2 (6H, OACH2, OACH, OACH3 from acetate
group), 7–9.5 (1H, OH from acid group).
Poly(FAVE-8-alt-MA)
>
19F NMR (377 MHz, d6-acetone, d): ꢁ81 (3F, CF3), ꢁ113.6
(2F, CF2ACF3), ꢁ126.3 (2F, CH2ACF2), (ꢁ121.8)–(ꢁ123.7)
(10 F, ACF2).
Poly(VEC2PMe-alt-IA)
1H NMR (400 MHz, d6-DMSO, d): 3.5–3.7 (6H, CH3), 4.0–4.3
(2H, CH2-O), 1.2–3.1 (9H, CH2 from IA, OACH, CH2AP, and
CH2 from VEC2PMe). 13C NMR (400 MHz, d6-DMSO, d): 170–
175 (3C, C, and C¼¼O) 20–30 (3C, P-CH2, and CH2 of IA), 55–
70 (3C, OACH2, OACH, and ACH2 from VEC2PMe), 52 (2C,
CH3), 31P NMR (162 MHz, d6-DMSO, d): 27.28.
Poly(VEC2PMe-alt-BM)
1H NMR (400 MHz, d6-acetone, d): 0.7–1.7 (7H, CH3 and CH2
from BM), 1.7–2.5 (4H, P-CH2 and CH2 from ethyl group),
4.0–4.7 (2H, OACH, and NACH2), 3.0–3.6 (4H, OACH2, and
2CH from succinimide ring). 13C NMR (400 MHz, d6-acetone,
d): 175–180 (2C, C¼¼O) 14–35 (4C, PACH2, 2CH2, and CH3
from BM), 55–70 (3C, OACH2, OACH, and ACH2 from
VEC2PMe), 50–63 (4C, OACH3, NACH2, and CH succinimide
ring), 64–80 (2C, OACH and OACH2). 31P NMR (162 MHz,
d6-acetone, d): 31.0.
REFERENCES AND NOTES
1 Quittmann, U.; Lecamp, L.; El Khatib, W.; Youssef, B.; Bunel,
C. Macromol. Chem. Phys. 2001, 202, 628–635.
2 Zhang, Y.; Tebby, J. C.; Wheeler, J. W. Eur. Polym. J. 1998,
35, 209–214.
3 Horrocks, A. R.; Zhang, S. Polymer 2001, 42, 8025–8033.
Poly(VEC2PMe-alt-MM)
4 Ebdon, J. R.; Price, D.; Hunt, B. J.; Joseph, P.; Gao, F.;
Milnes, G. J.; Cunliffe, L. K. Polym. Deg. Stab. 2000, 69,
267–277.
1H NMR (400 MHz, d6-DMSO, d): 1.7–2.5 (4H, PACH2 and
CH2 from ethyl group), 4.0–4.4 (1H, OACH), 3.2–3.9 (11H,
WWW.MATERIALSVIEWS.COM
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JOURNAL OF
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ARTICLE
WWW.POLYMERCHEMISTRY.ORG
5 Moszner, N.; Pavlinec, J.; Lamparth, I.; Zeuner, F.; Anger-
mann, J. Macromol. Rapid Commun. 2006, 27, 1115–1120.
23 Blanchard, G. J.; Kohli, P. US 6528603; Board of Trustees
Operating Michigan State University, 2003; p 16.
6 Moszner, N.; Salz, U.; Zimmermann, J. Dent. Mater. 2005, 21,
895–910.
24 Rampars, H.; Takahara, J. Japanese Kokai Tokkyo Koho;
Mitsubishi Chemical Corp.: JP 170912, 2005, p 10.
7 Sahin, G.; Avci, D.; Karahan, O.; Moszner, N. J. Appl. Polym.
Sci. 2009, 114, 97–106.
25 Brice, J. L.; Meerdink, J. E.; Stahl, S. S. Org. Lett. 2004, 6, 4799.
26 Bosch, M.; Schlaf, M. J. Org. Chem. 2003, 68, 5225–5227.
27 Muzart, J. Tetrahedron 2005, 61, 5955–6008.
8 Zeuner, F.; Moszner, N.; Drache, M.; Rheinberger, V. Phos-
phorus Sulfur Silicon Relat. Elem. 2002, 177, 2263.
28 El Asri, Z.; Chougrani, K.; Negrell-Guirao, C.; David, G.; Bou-
tevin, B.; Loubat, C. J. Polym. Sci. Part A: Polym. Chem. 2008,
46, 4794–4803.
9 Zeuner, F.; Moszner, N.; Volkel, T.; Vogel, K.; Rheinberger,
V. Phosphorus Sulfur Silicon Relat. Elem. 1999, 144–146,
133–136.
29 Chougrani, K.; Boutevin, B.; David, G. Eur. Polym. J. 2008,
44, 1771.
10 Zakikhani, M.; Davis, J. Eur. Pat. Appl.; Albright & Wilson
UK Limited: UK. EP 768889, 1997; p 10.
30 Jeanmaire, T.; Hervaud, Y.; Boutevin, B. Phosphorus Sulfur
Silicon Relat. Elem. 2002, 177, 1137–1145.
11 Okamoto, T.; Mori, H.; Matsuda, H. U.S.; Okura Industrial
Co.: Japan. US 4433124, 1984; p 8.
31 Kokubo, T.; Iwatsuki, S.; Yamashita, Y. Macromolecules
1968, 1, 482–488.
12 David, G.; Negrell-Guirao, C.; Iftene, F.; Boutevin, B.; Chou-
grani, K. Polym. Chem. 2012, 3, 265–274.
32 Boutevin, B.; Cersosimo, F.; Youssef, B. Macromolecules
1992, 25, 2842–2846.
13 Yu, Z.; Zhu, W. X.; Cabasso, I. J. Polym. Sci. Part A: Polym.
Chem. 1990, 28, 227–230.
33 Braun, D.; Schacht, M.; Elsasser, H.; Tudos, F. Macromol.
Rapid Commun. 1997, 18, 335–342.
14 Negrell-Guirao, C.; David, G.; Boutevin, B.; Chougrani, K.
J. Polym. Sci. Part A: Polym. Chem. 2011, 49, 3905–3910.
34 Wasley, W. L.; Pittman, A. G. J. Polym. Sci. 1972, 10, 279.
35 Iwatsuki, S.; Yamashita, Y. Makromol. Chem. 1967, 104, 263–274.
15 Negrell-Guirao, C.; Boutevin, B. Macromolecules 2009, 42,
2446–2454.
36 Basturkmen, M.; Rzaev, Z. M. O.; Akovali, G.; Kisakurek, D.
J. Polym. Sci. Part A: Polym. Chem. 1995, 33, 7–13.
16 Wu, Q.; Weiss, R. A. J. Polym. Sci. Part B: Polym. Phys.
2004, 42, 3628–3641.
37 Fujimori, K. Polym. Bull. (Berlin) 1985, 13, 459–462.
17 D’Agosto, F.; Charreyre, M.-T.; Delolme, F.; Dessalces, G.;
Cramail, H.; Deffieux, A.; Pichot, C. Macromolecules 2002, 35,
7911–7918.
38 Hao, X.; Fujimori, K.; Tucker, D. J.; Henry, P. C. Eur. Polym.
J. 2000, 36, 1145–1150.
18 Auvergne, R.; Saint, L. R.; Joly-Duhamel, C.; Robin, J. J.; Bou-
tevin, B. J. Polym. Sci. Part A: Polym. Chem. 2007, 45, 1324–1335.
€
39 Bingol, B.; Hart-Smith, G.; Barner-Kowollik, C.; Wegner, G.
Macromolecules 2008, 41, 1634–1639.
19 Tayouo, R.; David, G.; Ameduri, B. Eur. Polym. J. 2010, 46,
1111–1118.
40 Shulyndin, S. V.; Levin, Y. A.; Ivanov, B. E. Russ. Chem.
Rev. 1981, 50, 1653–1677.
20 Kohli, P.; Blanchard, G. J. Langmuir 1999, 15, 1418–1422.
41 Vahabi, H.; Longuet, C.; Ferry, L.; David, G.; Robin, J.-J.;
Lopez-Cuesta, J.-M. Polym. Int. 2012, 61, 129–134.
21 Kohli, P.; Rini, M. C.; Major, J. S.; Blanchard, G. J. J. Mater.
Chem. 2001, 11, 2996–3001.
42 David, G.; El Asri, Z.; Reach, S.; Castignolles, P.; Guillaneuf,
Y.; Lacroix-Desmazes, P.; Boutevin, B. Macromol. Chem. Phys.
2009, 210, 631.
22 Kohli, P.; Scranton, A. B.; Blanchard, G. J. Macromolecules
1998, 31, 5681–5689.
12
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