Synthesis and characterization of some bis(hydroxyalkyl)- and bis(hydroxyester)-functionalized disiloxanes

Article abstract of DOI:10.1515/mgmc-2012-0010

Novel hydroxyester disiloxanes (1,3-bis(6-hydroxyhexa noylmethyl)-1,1,3,3- tetramethyl disiloxane and 3-bis(2-hydroxypropanoylmethyl)tetramethyl disiloxane) were synthesized, and preparation of other known monomers, namely 1,3-bis(hydroxypropyl)-1,1,3,3-tetramethyl disiloxane, 1,3- bis(hydroxyethoxypropyl)-1,1,3,3-tetramethyl disiloxane and 1,3- bis(hydroxymethyl)-1,1,3,3-tetramethyl disiloxane was developed to obtain better yields and reduce production time and expense. All compounds were characterized by infrared spectroscopy, using ¹H NMR, ¹³C NMR, and ²⁹Si NMR and were reacted with diisocyanates, resulting in poly(siloxane-urethane) copolymers with unique properties.

Full text of DOI:10.1515/mgmc-2012-0010

DOI 10.1515/mgmc-2012-0010ꢀ
ꢀMain Group Met. Chem. 2012; 35(3-4): 91–97
a,
ESr i yk anP utshz t ea i s*,iJsózsaenf NdagycahndaÖrdaöncWtaegnreirzation of some
bis(hydroxyalkyl)- and bis(hydroxyester)-
functionalized disiloxanes
Abstract: Novel hydroxyester disiloxanes (1,3-bis(6-hyd- antithrombogenic (Briganti et al., 2006; Spiller et al.,
roxyhexanoylmethyl)-1,1,3,3-tetramethyl disiloxane and 2007; Losi et al., 2010; Soldani et al., 2010), general flex-
3-bis(2-hydroxypropanoylmethyl)tetramethyl disiloxane) ible elastomers with approved heat-resistance (Krol
were synthesized, and preparation of other known mono- et al., 2010) and high tensile strength (Chuang et al.,
mers, namely 1,3-bis(hydroxypropyl)-1,1,3,3-tetramethyl 2004), flame retardants or synergists in various polymers
disiloxane, 1,3-bis(hydroxyethoxypropyl)-1,1,3,3-tetrame- (Benrashid and Nelson, 1995; Lin et al., 2001; Nishihara
thyldisiloxaneand1,3-bis(hydroxymethyl)-1,1,3,3-tetrame- et al., 2003; Chen and Jiao, 2009; Hamdani et al., 2009;
thyl disiloxane was developed to obtain better yields and Singh and Jain, 2009; Chrusciel and Lesniak, 2011) and
reduce production time and expense. All compounds were other special applications (Ekin et al., 2007).
1
characterized by infrared spectroscopy, using H NMR,
Blending the unique properties of polysiloxanes and
13C NMR, and 29Si NMR and were reacted with diisocy- polyurethanes in copolymers has challenged several
anates, resulting in poly(siloxane-urethane) copolymers research groups. Theoretically, the wide service tem-
with unique properties.
perature (from -120°C to 120°C), hydrolytic and oxidative
stability, low surface energy, good biocompatibility and
Keywords: biocompatibility; bis(hydroxyalkyl) functional- good hemocompatibility of polysiloxanes can be aided
ized disiloxane; bis(hydroxyester) functionalized disilox- by the excellent mechanical properties of polyurethanes.
ane; flame retardance; phase miscibility; poly(siloxane- Investigations have revealed that simple blending of these
urethane) copolymers.
materials is totally unsatisfactory; the major reason for
deterioration of physical properties is the incompatibility
of non-polar siloxane segments with polar urethane hard
segments and the weak interfacial adhesion between
them. There have been several attempts to achieve better
phase miscibility (Ebdon et al., 1986; Stanciu et al.,
1999a,b; Ioan et al., 2002) to improve mechanical prop-
erties. Different preparation techniques were compared
(Majumdar and Webster, 2007); the polysiloxane back-
bone was modified with polar side chains or end groups,
or a second comacrodiol (typically a polyether polyol) was
added to the polysiloxanes (Adhikari et al., 1999, 2000;
Gunatillake et al., 2000). But only a very few efforts have
approached the phase miscibility problem by altering the
chain extender in the hard segment (Adhikari et al., 2002,
2003; Chuang et al., 2004).
*Corresponding author: Erika Pusztai, Department of Inorganic
and Analytical Chemistry, Budapest University of Technology
and Economics, 1111 Budapest, Szent Gellért tér 4, Hungary,
e-mail: pusztaierika@hotmail.com
József Nagy: Department of Inorganic and Analytical Chemistry,
Budapest University of Technology and Economics, 1111 Budapest,
Szent Gellért tér 4, Hungary
Ödön Wagner: Department of Inorganic and Analytical Chemistry,
Budapest University of Technology and Economics, 1111 Budapest,
Szent Gellért tér 4, Hungary
a
Present address: Organosilicon Research Center, University of
Wisconsin-Madison, 1101 University Avenue, Madison, 53706, USA
Introduction
That soft and hard segments in polyether and poly-
ester polyurethanes can be observed is well known
Poly(siloxane-urethane) copolymers have received (Krol, 2007). Hard segments consist of diisocyanate units
increasing attention in recent decades. They may satisfy and chain extender molecules, typically in the case of
the demand for waterborne polyurethanes to produce 4,4′-diphenylmethane diisocyanate (MDI) and butane-
environmentally friendly waterproof polymers with 1,4-diol (BDO), the MDI2-BDO units. Better phase mis-
excellent weather resistance (Kozakiewicz, 1996; Prabu cibility might be obtained by tailoring not only the soft
and Alagar, 2004; Rath et al., 2009), moisture curable segment molecules with polar groups but also producing
coatings for medical uses that are biocompatible and disiloxane chain extenders so that the hard segments
Brought to you by | Heinrich Heine Universität Düsseldorf
Authenticated | 93.180.53.211
Download Date | 11/7/13 10:43 PM

92ꢀ
ꢀE. Pusztai et al.: Synthesis and characterization of some disiloxanes
contain – (CH3)2Si-O- units. Different chain extenders ane (4) and 1,3-bis(hydroxymethyl)-1,1,3,3-tetramethyl disi-
benefit different macrodiols and diisocyanates. Varying loxane (5) (Speier et al., 1949; Greber and Jager, 1962; Adhi-
the end groups on the disiloxane chain permits them kari et al., 2003; Braun et al., 2007; Frampton et al., 2010).
1
13
to be used in a wide range of poly(siloxane-urethane) All compounds were analyzed by FT-IR, H-NMR, C-NMR
copolymers.
and 29Si NMR.
Hydroxyester functionalized disiloxanes are the object
of only one patent, published in 1956 (Merker, 1956), and
no other references are available. Accordingly, no basic Results and discussion
physical and spectroscopic data have been yet reported.
Their application in polyurethanes has never been men-
Synthesis and characterization
tioned, although, due to their polar carbonyl group, they
of hydroxyester disiloxanes
possess very desirable properties.
Hydroxyalkyl functionalized siloxanes are known in
the literature. They are usually synthesized in a hydro-
silylation reaction with H2PtCl6 6H2O (Speier’s catalyst) or
Pt-divinyl-tetramethyl-disiloxane complex (Karstedt cata-
lyst) (Greber and Jager, 1962; Braun et al., 1989, 2007). The
hydrosilylation reaction is fundamental in silicone chem-
istry; investigation of both the catalysts and the resultant
products has been the objective of several patents and sci-
entific publications (Speier et al., 1956, 1957; Ryan et al.,
1960; Kossmehl et al., 1986; Chu and Frye, 1993; Lappert
and Scott, 1995; Sabourault et al., 2002; Jankowiak et al.,
2005; Zhu et al., 2005).
In this work, we provide a new bis(hydroxyester) func-
tionalized disiloxane [1,3-bis(6-hydroxyhexanoylmethyl)-
1,1,3,3-tetramethyl disiloxane (1)], as well as a simple
preparation method for 3-bis(2-hydroxypropanoylmethyl)
tetramethyl disiloxane (2), and characterization of both
compounds. These diols can be used as chain extenders
in poly(siloxane-urethane) copolymers, improving the
phase miscibility between hard and soft segments due to
their polar ester groups.
Compound 1 was prepared as depicted in Scheme 1. 2 was
prepared as depicted in Scheme 2. After the procedure
described in the Experimental section, only technical
grade products of ꢀ>ꢀ90% purity were obtained. For further
analysis, they were purified on a semi-preparative HPLC
column. The novel compound 1 is expected to provide the
most flexible polymers, as well as high tensile strength.
Compound 2 is expected to provide a slower reaction with
diisocyanates due to its secondary hydroxyl group, and
thus pot time may be lengthened using compound 2.
The hydrolytic stability of the monomers was inves-
tigated by boiling 1 and 2 separately in water. After 1 day
boiling, they were totally decomposed, but after being
stored for 1 year in air at ambient temperature, they did
not show any change. Polymers prepared from these
monomers are hydrolytically stable. No reduction in
tensile strength or change in hardness was measureable
after 1 day boiling in 0.1 M KOH solution.
Synthesis and characterization of
hydroxyalkyl disiloxanes by hydrosilylation
reaction
Furthermore, we provide detailed characterization and
synthesis methods for preparing more efficiently three other
monomers that were partially described in earlier studies:
1,3-bis(3-hydroxypropyl)-1,1,3,3-tetramethyl disiloxane (3), Compounds 3 and 4 were synthesized by the hydro-
1,3-bis(6-hydroxyethoxypropyl)-1,1,3,3-tetramethyl disilox- silylation reaction depicted in Schemes 3–6. Among all
Scheme 1ꢀSynthesis of 1,3-bis(5-hydroxyhexanoylmethyl)tetramethyl disiloxane (1).
Scheme 2ꢁSynthesis of 1,3-bis(2-hydroxypropanoylmethyl)tetramethyl disiloxane (2).
Brought to you by | Heinrich Heine Universität Düsseldorf
Authenticated | 93.180.53.211
Download Date | 11/7/13 10:43 PM

E. Pusztai et al.: Synthesis and characterization of some disiloxanesꢀ
ꢀ93
Scheme 3ꢁSynthesis of 1,3-bis(3-trimethylsiloxypropyl)tetramethyl disiloxane (3b).
Scheme 4ꢀSynthesis of 1,3-bis(3-hydroxypropyl)tetramethyl disiloxane (3) by hydrolysis of 1,3-bis(3-trimethylsiloxypropyl)tetramethyl
disiloxane (3b).
Scheme 5ꢀSynthesis of 1,3-bis(6-trimethylsiloxyethoxypropyl)tetramethyl disiloxane (4b).
Scheme 6ꢀSynthesis of 1,3-bis(6-hydroxyethoxypropyl)tetramethyl disiloxane (4) by hydrolysis of 1,3-bis(6-trimethylsiloxyethoxypropyl)
tetramethyl disiloxane (4b).
disiloxanes of this study, 3 is most entirely described
To reduce time and cost in the preparation of 3, we
because it is one of the simplest examples of hydrosilyla- developed the hydrolysis reaction. Because of several side
tion reactions (Greber and Jager, 1962; Adhikari et al., reactions that occur with an excess of water, methanoly-
2003; Braun et al., 2007; Frampton et al., 2010).
sis is the usual procedure (Braun et al., 1987). We applied
Several research groups have investigated the mecha- water in an approximately stoichiometric amount with
nism of these reactions and developed new catalysts. p-toluene sulphuric acid as catalyst. With this method, the
Although it is known that the basis of the catalysis is the oxi- desired product was obtained in very good yield within 2 h
dation reduction process of Pt(0) and Pt(IV) (Chu and Frye, and without much organic solvent waste.
1993), and though it was found to be a very active catalyst in
the presence of ionic liquids (Hofmann et al., 2008; Macie-
jewski et al., 2012), PtCl4 salt catalyst is not frequently used Synthesis and characterization of
in hydrosilylation. PtCl4 is commercially available, and,
1,3-bis(hydroxymethyl)tetramethyl
with regard to efficient Pt-content, it is more cost-efficient
disiloxane
than, for example, H2PtCl6. Additionally, PtCl4 is acquirable
as a dry salt, which is quite important due to the fact that Compound 5 was synthesized by the reaction depicted
even small traces of water can greatly decrease the effect in Schemes 7 and 8. Although compound 5 is one of the
of a catalyst (Feng and Cui, 2000). In our experiments, we earliest examples of disiloxanes, no detailed NMR char-
found PtCl4 to be a very efficient catalyst in hydrosylilation acterization has been available (Speier et al., 1949). This
reactions according to our earlier expectations based on the preparation method was improved by ameliorateing the
mechanism of catalysis of Pt(IV) (Chu and Frye, 1993).
process of methanolysis.
Brought to you by | Heinrich Heine Universität Düsseldorf
Authenticated | 93.180.53.211
Download Date | 11/7/13 10:43 PM

94ꢀ
ꢀE. Pusztai et al.: Synthesis and characterization of some disiloxanes
Scheme 7ꢀSynthesis of 1,3-bis(acetoxymethyl)tetramethyl disiloxane (5a).
Germany, ꢀ>ꢀ99%) and distilled two times before use on a laboratory
column with 20 theoretical plates. 1,1,3,3-tetramethyl disiloxane, hexa-
methyl disilazane (Wacker, Germany) and dimethyl formamide (ꢀ>ꢀ99.8%)
from Carlo Erba Reagenti (Italy) were distilled prior to use. Allyl alcohol,
allyloxy ethanol, diethyl ether and petroleum ether were purchased
from Sigma-Aldrich (USA) and used as received. Potassium hydrox-
ide (ꢀ>ꢀ99%), potassium carbonate (ꢀ>ꢀ99%), calcium chloride (ꢀ>ꢀ99%)
and sodium sulphate (ꢀ>ꢀ99%) are the products of Molar Chemicals
(Hungary), and were used as received. Platinum (IV) chloride (ꢀ>ꢀ98%),
lactic acid (70% aqueous solution) and ε-caprolactone (ꢀ>ꢀ98%) were
purchased from Merck (Germany), and used without further treatment.
1H and 13C NMR experiments were performed on a Bruker
DRX-300, and 29Si NMR experiments were performed on a Bruker
DRX-500 spectrometer. All compounds were dissolved in CDCl3. Com-
pound 1 and 2 were purified before analysis on a semi-preparative
HPLC column with Perkin Elmer Series 200 equipment; methanol-
water eluent was used. IR spectra were recorded with a Bruker
ALPHA FT-IR spectrometer analyzing neat film on KBr pellets.
Scheme 8ꢁSynthesis of 1,3-bis(hydroxymethyl)tetramethyl disiloxane (5).
Reaction with diisocyanate
All prepared disiloxanes were reacted with Lupranat MI
(BASF) diisocyanate and Lupranol-1301 (BASF) trifunctional
polyether polyol in a molar ratio of 2:4:1, respectively. Disilox-
anes were prepared as described in the Experimental section.
Preparation occurred by one-pot reaction in n-butyl acetate
solution (30% polymer content) at 115°C for 2 h stirring. After
drying at room temperature, residual solvent was revealed at
60°C, and the films were annealed at 120°C for 3 h.
All received films were clear, tough, cross-linked poly-
mers with about 90 ShA hardness and 35–75 MPa ultimate
tensile strength. Considering the fact that these polymers
contain at least 25% disiloxane compound, these proper-
ties are unique. Detailed investigation of the use of these
disiloxane compounds and the polymers made from them
will be the objective of further studies.
Chemical synthesis
Hydrolysis of chloromethyl dimethylchlorosilane
2.24 mol (320.5 g) chloromethyl dimethylchlorosilane was added
dropwise to 450 ml water and 600 ml petroleum ether, under con-
stant, vigorous stirring and cooled in a cold water bath. The mixture
was stirred for a further 2 h. The organic layer was separated, washed
with water and dried with CaCl2 overnight. After the ether was evapo-
rated, 1,3-bis(dichloromethyl)tetramethyl disiloxane was distilled
under reduced pressure. Bp. 85°C/20 Torr, nD25ꢀ=ꢀ1.437, 86% yield.
Conclusion
Two hydroxyester disiloxanes were synthesised and charac-
terized by NMR and IR spectroscopy. Three other hydroxy-
alkyl disiloxanes were prepared using newly developed syn-
thesis methods and characterized similarly. All compounds
were shown to be potential monomers in the preparation of
new poly(siloxane-urethane) copolymers. By adding these
disiloxanes, especially the novel hydroxyester functional-
ized disiloxanes, to polysiloxane-polyurethane blends as
chain extenders, advanced phase miscibility is expected,
which results in better mechanical properties.
Preparation of 1,3-bis(5-hydroxyhexanoylmethyl)
tetramethyl disiloxane (1)
1.00 mol (231.0 g) of 1,3-bis(chloromethyl)tetramethyl disiloxane,
2.00 mol (340.0 g) potassium caprolactate (obtained from 2.00 mol
ε-caprolactone and 2.00 mol KOH in aqueous solution from which
water was evaporated in vacuum, following which the salt was dried
at 80°C for a day) and 600 g dimethyl formamide was refluxed for
5 h. The precipitated potassium chloride was removed by filtration,
and the solvent was distilled. The product was dissolved in diethyl
ether and washed with water. The organic layer was separated and
dried with Na2SO4. After diethyl ether was evaporated, the product
was filtered. No distillation occurred because this compound decom-
poses below its boiling point. Tdecomp.ꢀ=ꢀ200°C (in air, determined with
thermogravimetric analysis); nd25ꢀ=ꢀ1.455, 65% yield. 1H NMR (300.133
MHz, CDCl3, δ): 3.78 (s, -O-CH2-Si-), 3.53 (t, Jꢀ=ꢀ6.8 Hz, HO-CH2-), 2.35 (t,
Jꢀ=ꢀ7.3 Hz, -CH2-COO-), 1.57 (m, HO-CH2-CH2-CH2-CH2-), 1.49 (m, HO-CH2-
Experimental
Materials and methods
Chloromethyldimethylchlorosilane was synthesized in our laboratory CH2-), 1.28 (m, HO-CH2-CH2-CH2-), 0.136 (s, -Si-CH3). 13C NMR (75.403
after Speier’s method (Speier, 1951) from trimethylchlorosilane (Merck, MHz, CDCl3, δ): 178.27 (-COO-), 62.08 (HO-CH2-), 58.74 (-CH2-Si-),
Brought to you by | Heinrich Heine Universität Düsseldorf
Authenticated | 93.180.53.211
Download Date | 11/7/13 10:43 PM

E. Pusztai et al.: Synthesis and characterization of some disiloxanesꢀ
ꢀ95
34.21 (CH2-COO-), 31.36 (HO-CH2-CH2-), 25.04 (-CH2-CH2-COO-), 24.70 p-toluenesulfonic acid for 2 h. The mixture was distilled. Bp. 70°C/20
1
(HO-CH2-CH2-CH2-), -2.45 (-Si-CH3). 29Si NMR (99.314 MHz, CDCl3, δ): Torr, nD23ꢀ=ꢀ1.442, 88% yield. H NMR (300.13 MHz, CDCl3, δ): 3.48 (t,
3.42 ppm. IR 756, 798, 836, 1050, 1163, 1254, 1285, 1364, 1418, 1458, 1731, Jꢀ=ꢀ6.9 Hz, HO-CH2- C H 2-), 1.52 (m, Jꢀ=ꢀ6.9, 8.5 Hz, -HO-CH2-CH2-), 0.46 (t,
2864, 2937, 3365 cm-1. Elemental analysis calculated for C18H38Si2O7: C, Jꢀ=ꢀ8.5 Hz, -CH2-Si-), 0.01 (s, -Si-CH3) . 13C NMR (75.40 MHz, CDCl3, δ):
51.15; H, 9.06. Found: C, 51.66; H, 9.33.
65.07 (HO-CH 2-CH2-), 26.34 (HO-CH2-CH 2-), 13.95 (-CH 2 -Si-), 0.20 (-Si-
CH 3). 29Si NMR (99.31 MHz, CDCl3, δ): 7.95 ppm. IR 704, 773, 793, 835,
1010, 1046, 1178, 1251, 1411, 1437, 2874, 2930, 2955, 3315 cm-1. Elemental
analysis calculated for C10H26Si2O3: C, 47.95; H, 10.46. Found: C, 48.14;
H, 10.23.
Preparation of 1,3-bis(2-hydroxypropanoylmethyl)-
tetramethyl disiloxane (2)
1.00 mol (231.0 g) of 1,3-bis(chloromethyl)tetramethyl disiloxane, 2.00
mol (256.0 g) potassium lactate (obtained from lactic acid and potas-
sium carbonate in aqueous solution from which water was evaporated
in vacuum, following which salt was dried at 80°C for a day) and 535 g
dimethyl formamide were refluxed for 5 h. The precipitated potassium
chloride was removed by filtration, and the solvent was distilled. The
product was dissolved in diethyl ether and washed with water. The
organic layer was separated and dried with Na2SO4. After diethyl ether
was evaporated, the product was distilled under reduced pressure. Bp.
140°C/0.4 Torr, nD23ꢀ=ꢀ1.442, 74% yield. 1H NMR (300.133 MHz, CDCl3, δ):
4.37 (q, Jꢀ=ꢀ7.0 Hz, CH3-CH-(OH)-), 3.89 (d, Jꢀ=ꢀ14.3 Hz, -CHaHb-Si-), 3.84 (d,
Jꢀ=ꢀ14.3 Hz, -CHaHb-Si-), 1.34 (d, Jꢀ=ꢀ7.3 Hz, CH3-CH(OH)-), 0.14 (s, -Si-CH3).
13C NMR (75.403 MHz, CDCl3, δ): 177.56 (-COO-), 67.30 (CH3-CH(OH)-), 59.41
(CH3-CH(OH)-), -2.52 (-Si-CH3). 29Si NMR (99.314 MHz, CDCl3, δ): 3.36 ppm.
IR 721, 762, 798, 835, 874, 1042, 1126, 1198, 1253, 1287, 1373, 1418, 1451,
1730, 2909, 2960, 3468 cm-1. Elemental analysis calculated for C12H26Si2O7:
C, 42.58; H, 7.74. Found: C, 42.96; H, 8.05.
Preparation of (6-hydroxyethoxypropyl)trimethylsilane (4a)
0.370 mol (40.1 g) trimethyl chlorosilane and 0.370 mol (59.6 g)
hexamethyl disilazane were mixed and 1 mol (102.0 g) of allyloxy-
ethanol was added dropwise to the mixture with vigorous stirring
and cooling in an ice-water bath. The mixture was then heated and
refluxed for 3 h. The salt formed was filtered off, and the filtrate was
distilled. Bp. 60°C/20 Torr, nD25ꢀ=ꢀ1.421, 76% yield.
Preparation of 1,3-bis(6-trimethylsiloxyethoxypropyl)
tetramethyl disiloxane (4b)
0.268 mol (35.9 g) 1,1,3,3-tetramethyldisiloxane was slowly added
to 0.590 mol (102.7 g) (6-hydroxyethoxypropyl)trimethylsilane con-
taining a catalytic amount of anhydrous PtCl4 at 80°C. The mixture
was stirred for a further 3 h at 120°C. Subsequent distillation under
reduced pressure yielded the desired compound. Bp. 174°C/0.6 Torr,
nD24ꢀ=ꢀ1.432, 76% yield.
Preparation of (2-propenyloxy)trimethylsilane (3a)
0.730 mol (79.6 g) trimethyl chlorosilane and 0.730 mol (118.1 g) hexa-
methyl disilazane were mixed and 2 mol (116.0 g) of allyl alcohol was
added dropwise to the mixture with vigorous stirring and cooling in
an ice-water bath. The mixture was then heated and refluxed for 3
h. The salt formed was filtered off, and the filtrate was distilled. Bp.
100–101°C, nD25ꢀ=ꢀ1.394, 62% yield.
Preparation of 1,3-bis(6-hydroxyethoxypropyl)-
tetramethyl disiloxane (4) by hydrolysis of 1,3-bis(6-
trimethylsiloxyethoxypropyl)tetramethyl disiloxane (4b)
0.202 mol (97.1 g) 1,3-bis(6-trimethylsiloxyethoxypropyl)tetramethyl
disiloxane, 0.556 mol (10.0 g) water were heated and stirred with 0.1
g of p-toluenesulfonic acid for 2 h. The mixture was distilled. Bp.
Preparation of 1,3-bis(3-trimethylsiloxypropyl)
tetramethyl disiloxane (3b)
1
65°C/20 Torr, nD25ꢀ=ꢀ1.452, 86% yield. H NMR (300.13 MHz, CDCl3, δ):
3.47 (t, Jꢀ=ꢀ5.0 Hz, HO-CH2-CH2-), 3.30 (t, Jꢀ=ꢀ5.0 Hz, HO-CH2-CH2-), 3.21 (t,
Jꢀ=ꢀ6.9 Hz, -O-CH2-), 1.39 (m, -O-CH2-CH2-CH2-), 0.29 (t, Jꢀ=ꢀ8.5 Hz, -CH2-
Si-), -0.16 (s, -Si-CH3). 13C NMR (75.40 MHz, CDCl3, δ): 73.41 (HO-CH2-
CH2-), 71.45 (-O-CH2-CH2-), 60.76 (HO-CH2-CH2-), 22.77 (-O-CH2-CH2-),
13.61 (-CH2-Si-), -0.24 (-Si-CH3). 29Si NMR (99.31 MHz, CDCl3, δ): 7.46
ppm. IR 705, 773, 795, 835, 899, 943, 1044, 1098, 1117, 1186, 1250, 1358,
1411, 1456, 2865, 2929, 2953, 3446 cm-1. Elemental analysis calculated
for C14H34Si2O5: C, 49.66; H, 10.12. Found: C, 49.83; H, 10.48.
0.550 mol (73.7 g) 1,1,3,3-tetramethyldisiloxane was slowly added
to 1.21 mol (157.3 g) (2-propenyloxy)trimethylsilane containing a
catalytic amount of anhydrous PtCl4 (1 ml of 1% 2-propanol solution)
at 80°C. The mixture was stirred further for 2.5 h at 120°C. Subse-
quent distillation under reduced pressure yielded the desired com-
pound. Bp. 127°C/1.0 Torr, nD24ꢀ=ꢀ1.424, 81% yield.
Preparation of 1,3-bis(3-hydroxypropyl)tetramethyl
disiloxane (3) by hydrolysis of
1,3-bis(3-trimethylsiloxypropyl)tetramethyl
disiloxane (3b)
Preparation of 1,3-bis(acetoxymethyl)tetramethyl
disiloxane (5a)
0.965 mol (223.0 g) 1,3-bis(chloromethyl)tetramethyl disiloxane and
2.00 mol (196.0 g) potassium acetate were added to 450 ml dime-
0.127 mol (50.0 g) 1,3-bis(3-trimethylsiloxypropyl)tetramethyldisilox- thyl formamide. The mixture was refluxed for 6 h. The precipitated
ane and 0.278 mol (2.0 g) water were heated and stirred with 0.1 g of potassium chloride was filtered, the solvent distilled, the residue
Brought to you by | Heinrich Heine Universität Düsseldorf
Authenticated | 93.180.53.211
Download Date | 11/7/13 10:43 PM

96ꢀ
ꢀE. Pusztai et al.: Synthesis and characterization of some disiloxanes
solved in diethyl ether, washed with water and dried with CaCl2. After was distilled under reduced pressure. Bp. 95°C/0.3 Torr, nD25ꢀ=ꢀ 1.435,
the diethyl ether was evaporated, the product was distilled under 68% yield. 1H NMR (300.13 MHz, CDCl3, δ): 3.20 (s, HO-CH2-Si-), 0.05
reduced pressure. Bp. 85°C/0.3 Torr, nD25ꢀ=ꢀ1.422, 85% yield.
(s, -Si-CH3). 13C NMR (75.40 MHz, CDCl3, δ): 55.71 (HO-CH2-Si-), -1.61
(-Si-CH3). 29Si NMR (99.31 MHz, CDCl3, δ): 3.72 ppm. IR 714, 752, 793,
833, 1046, 1178, 1252, 1411, 1726, 2875, 2959, 3312 cm-1. Elemental
analysis calculated for C6H18Si2O3: C, 37.08; H, 9.33. Found: C, 37.84;
H, 9.67.
Preparation of 1,3-bis(hydroxymethyl)tetramethyl
disiloxane (5)
0.766 mol (210.0 g) 1,3-bis(acetoxymethyl)tetramethyl disiloxane
was dissolved in 560 ml methanol containing 5% HCl. The mixture
was refluxed for 1.5 h then 2/3 of the methanol was distilled away.
The same amount of abs. methanol was added to the residue which
was refluxed again for 1.5 h. These two steps were repeated two
further times. The third time, all the methanol was distilled, and
Acknowledgement: The authors thank Pál Kolonits for
NMR, József Nagy jr. and Gyulané Timkó for FT-IR, Jenő
Fekete and Péter Jenei for HPLC assistance. The authors
also thank Robert West for the language help.
the residue was dissolved in diethyl ether, washed with water and Received April 2, 2012; accepted May 29, 2012; previously published
dried with Na2SO4. After diethyl ether was evaporated, the product online July 12, 2012
References
Adhikari, R.; Gunatillake, P. A.; McCarthy, S. J.; Meijs, G. F. Effect of
chain extender structure on the properties and morphology
of polyurethanes based on H12MDI and mixed macrodiols
(PDMS-PHMO). J. Appl. Polym. Sci. 1999, 74, 2979–2989.
Adhikari, R.; Gunatillake, P. A.; McCarthy, S. J.; Meijs, C. F. Mixed
macrodiol-based siloxane polyurethanes. Effect of the
comacrodiol structure on properties and morphology. J. Appl.
Polym. Sci. 2000, 78, 1071–1082.
Adhikari, R.; Gunatillake, P. A.; McCarthy, S. J.; Meijs, G. F.
Low-modulus siloxane-based polyurethanes. I. Effect of the
chain extender 1,3-bis(4-hydroxybutyl)1,1,3,3-tetramethyidis-
iloxane (BHTD) on properties and morphology. J. Appl. Polym.
Sci. 2002, 83, 736–746.
Adhikari, R.; Gunatillake, P. A.; McCarthy, S. J.; Bown, M.; Meijs, G. F.
Low-modulus siloxane-polyurethanes. Part II. Effect of chain
extender structure on properties and morphology. J. Appl.
Polym. Sci. 2003, 87, 1092–1100.
Benrashid, R.; Nelson, G. L. Flammability improvement of
polyurethanes by incorporation of a silicone moiety into
the structure of block-copolymers. In Fire and Polymers II
– Materials and Tests for Hazard Prevention; Nelson, G. L. Ed.
American Chemical Society: Washington, 1995; pp. 217–235.
Braun, F.; Willner, L.; Hess, M.; Kosfeld, R. Synthesis of disiloxanes
containing hydroxyalkyl groups. J. Organomet. Chem. 1987,
332, 63–68.
Braun, F.; Willner, L.; Hess, M.; Kosfeld, R. Synthesis and charac-
terization of oligosiloxanes with hydroxyalkyl substituents. J.
Organomet. Chem. 1989, 366, 53–56.
Briganti, E.; Losi, P.; Raffi, A.; Scoccianti, M.; Munao, A.; Soldani,
G. Silicone based polyurethane materials: a promising
biocompatible elastomeric formulation for cardiovascular
applications. J. Mat. Sci. – Mat. Med. 2006, 17, 259–266.
Chen, X. L.; Jiao, C. M. Synergistic effects of hydroxy silicone oil on
intumescent flame retardant polypropylene system. J. Polym.
Res. 2009, 16, 537–543.
Chrusciel, J. J.; Lesniak, E. Preparation of flexible, self-extinguishing
silicone foams. J. Appl. Polym. Sci. 2011, 119, 1696–1703.
Chu, H. K.; Frye, C. L. Cyclohydrosilylation dimer formation-
evidence for Pt(0) – Pt(II) – Pt(IV) catalysis. J. Organomet.
Chem. 1993, 446, 183–189.
Chuang, F. S.; Tsen, W. C.; Shu, Y. C. The effect of different siloxane
chain-extenders on the thermal degradation and stability of
segmented polyurethanes. Polym. Degrad. Stab. 2004, 84,
69–77.
Ebdon, J. R.; Hourston, D. J.; Klein, P. G. Polyurethane-polysiloxane
simultaneous interpenetrating polymer networks. Adv. Chem.
Ser. 1986, 211, 171–193.
Ekin, A.; Webster, D. C.; Daniels, J. W.; Stafslien, S. J.; Casse, F.;
Callow, J. A.; Callow, M. E. Synthesis, formulation, and charac-
terization of siloxane-polyurethane coatings for underwater
marine applications using combinatorial high-throughput
experimentation. J. Coat. Tech. Res. 2007, 4, 435–451.
Feng, S. Y.; Cui, M. Z. Study of polysiloxanes containing epoxy
groups. I. Synthesis and characterization of polysiloxanes
containing 3-(2,3-epoxypropoxy)propyl groups. React. Funct.
Polym. 2000, 45, 79–83.
Frampton, M. B.; Subczynska, I.; Zelinsko, P. M. Biocatalytic
synthesis of silicon polyesters. Biomacromolecules 2010, 11,
1818–1825.
Greber, G.; Jager, S. Über oligomere Siliciumverbindungen mit
funktionellen Gruppen. 12. Mitt. Über Herstellung von
oligomeren siliciumorganischen Diolen und Diaminen und
ihre Umsetzungen mit organischen Diisocyanaten. Makromol.
Chem. 1962, 57, 150–191.
Gunatillake, P. A.; Meijs, G. F.; McCarthy, S. J.; Adhikari, R.
Poly(dimethylsiloxane)/poly(hexamethylene oxide) mixed
macrodiol based polyurethane elastomers. I. Synthesis and
properties. J. Appl. Polym. Sci. 2000, 76, 2026–2040.
Hamdani, S.; Longuet, C.; Perrin, D.; Lopez-Cuesta, J. M.;
Ganachaud, F. Flame retardancy of silicone-based materials.
Polym. Degrad. Stab. 2009, 94, 465–495.
Hofmann, N.; Bauer, A.; Frey, T.; Auer, M.; Stanjek, V.; Schulz, P. S.;
Taccardi, N.; Wasserscheid, P. Liquid-liquid biphasic, Platinum-
catalyzed hydrosilylation of allyl chloride with trichlorosilane
using an ionic liquid catalyst phase in a continuous loop
reactor. Adv. Synth. Cat. 2008, 350, 2599–2609.
Ioan, S.; Grigorescu, G.; Stanciu, A. Effect of segmented poly(ester-
siloxane)urethanes compositional parameters on differential
scanning calorimetry and dynamic-mechanical measurements.
Eur. Polym. J. 2002, 38, 2295–2303.
Brought to you by | Heinrich Heine Universität Düsseldorf
Authenticated | 93.180.53.211
Download Date | 11/7/13 10:43 PM

E. Pusztai et al.: Synthesis and characterization of some disiloxanesꢀ
ꢀ97
Jankowiak, M.; Maciejewski, H.; Gulinski, J. Catalytic reactions of
of PDMS-modified epoxy via urethane linkage: segmental
hydrosiloxanes with allyl chloride. J. Organomet. Chem. 2005,
690, 4478–4487.
correlation length, phase morphology, thermomechanical and
surface behaviour. Prog. Org. Coat. 2009, 65, 366–374.
Ryan, J. W.; Menzie, G. K.; Speier, J. L. The addition of silicon
hydrides to olefinic double bonds. 5. The addition to allyl
and metallyl chlorides. J. Am. Chem. Soc. 1960, 82,
3601–3604.
Kossmehl, G.; Neumann, W.; Schafer, H. Polymeric and oligomeric
dimethylsiloxanes with alcoholic groups and their conversions
into polymers with dimethylsiloxane and urethane moieties.
Makromol. Chem.-Macromol. Chem. Phys. 1986, 187,
1381–1388.
Kozakiewicz, J. Polysiloxaneurethanes, new polymers for potential
coating applications. Prog. Org. Coat. 1996, 27, 123–131.
Krol, P. Synthesis methods, chemical structures and phase
structures of linear polyurethanes. Properties and applications
of linear polyurethanes in polyurethane elastomers,
copolymers and ionomers. Prog. Mat. Sci. 2007, 52, 915–1015.
Krol, P.; Pielichowska, K.; Byczynski, L. Thermal degradation
kinetics of polyurethane-siloxane anionomers. Thermochim.
Acta 2010, 507–08, 91–98.
Sabourault, N.; Mignani, G.; Wagner, A.; Mioskowski, C. Platinum
oxide (PtO2). A potent hydrosilylation catalyst. Org. Lett. 2002,
4, 2117–2119.
Singh, H.; Jain, A. K. Ignition, combustion, toxicity, and fire
retardancy of polyurethane foams: a comprehensive review. J.
Appl. Polym. Sci. 2009, 111, 1115–1143.
Soldani, G.; Losi, P.; Bernabei, M.; Burchielli, S.; Chiappino, D.;
Kull, S.; Briganti, E.; Spiller, D. Long term performance of
small-diameter vascular grafts made of a poly(ether)urethane-
polydimethylsiloxane semi-interpenetrating polymeric
network. Biomaterials 2010, 31, 2592–2605.
Speier, J. L. A study of the chlorination of methylchlorosilanes.
J. Am. Chem. Soc. 1951, 73, 824–826.
Lappert, M. F.; Scott, F. P. A. The reaction pathway from Speier’s to
Karstedt’s hydrosilylation catalyst. J. Organomet. Chem. 1995,
492, C11–C13.
Lin, M. F.; Tsen, W. C.; Shu, Y. C.; Chuang, F. S. Effect of silicon and
phosphorus on the degradation of polyurethanes. J. Appl.
Polym. Sci. 2001, 79, 881–899.
Speier, J. L.; Daubert, B. F; McGregor, R. R. Acetoxymethyl and
hydroxymethyldisiloxanes. J. Am. Chem. Soc. 1949, 71,
1474–1475.
Losi, P.; Briganti, E.; Magera, A.; Spiller, D.; Ristori, C.; Battolla, B.;
Balderi, M.; Kull, S.; Balbarini, A.; Stefano, R.; Soldani, G. Tissue
response to poly(ether)urethane-polydimethylsiloxane-fibrin
composite scaffolds for controlled delivery of pro-angiogenic
growth factors. Biomaterials 2010, 31, 5336–5344.
Maciejewski, H.; Szubert, K.; Marciniec, B. New approach
to synthesis of functionalized silasesquioxanes via
hydrosilylation. Cat. Comm. 2012, 24, 1–4.
Speier, J. L.; Zimmerman, R.; Webster, J. The addition of silicon
hydrides to olefinic double bonds. 1. The use of phenylsilane;
diphenylsilane; phenylmethylsilane; amylsilane and tribro-
mosilane. J. Am. Chem. Soc. 1956, 78, 2278–2281.
Speier, J. L.; Webster, J. A.; Barnes, G. H. The addition of
silicon hydrides to olefinic double bonds. 2. The use of
group-VIII metal catalysts. J. Am. Chem. Soc. 1957, 79,
974–979.
Majumdar, P.; Webster, D. C. Surface microtopography in siloxane-
polyurethane thermosets. The influence of siloxane and extent
of reaction. Polymer 2007, 48, 7499–7509.
Spiller, D.; Losi, P.; Briganti, E.; Sbrana, S.; Kull, S.; Martinelli, I.;
Soldani, G. PDMS content affects in vitro hemocompatibility
of synthetic vascular grafts. J. Mat. Sci.-Mat. Med. 2007, 18,
1097–1104.
Stanciu, A.; Airinei, A.; Timpu, D.; Ioanid, A.; Ioan, C.; Bulacovschi,
V. Polyurethane/polydimethylsiloxane segmented copolymers.
Eur. Polym. J. 1999a, 35, 1959–1965.
Stanciu, A.; Bulacovschi, V.; Lungu, M.; Vlad, S.; Balint, S.; Oprea,
S. Mechanical behaviour of crosslinked poly(ester-siloxane)
urethanes. Eur. Polym. J. 1999b, 35, 2039–2044.
Zhu, X. L.; Zhang, M.; Zhang, Q. S.; Feng, S. Y.; Kong, X. Z. Synthesis
and characterization of bis(methoxyl hydroxyl)-functionalized
disiloxane and polysiloxane oligomers derivatives therefrom.
Eur. Polym. J. 2005, 41, 1993–2001.
Merker, R. R. Hydroxyester substituted siloxanes. US Patent
2,770,631; November 1956.
Nishihara, H.; Suda, Y.; Sakuma, T. I. Halogen- and phosphorus-
free flame retardant PC plastic with excellent moldability and
recyclability. J. Fire Sci. 2003, 21, 451–464.
Prabu, A. A.; Alagar, A. Mechanical and thermal studies of
intercross-linked networks based on siliconized polyurethane-
epoxy/unsaturated polyester coatings. Prog.Org. Coat. 2004,
49, 236–243.
Rath, S. K.; Chavan, J. G.; Sasane, S.; Srivastava, A.; Patri, M.;
Samui, A. B.; Chakraborty, B.C.; Sawant, S. N. Coatings
Brought to you by | Heinrich Heine Universität Düsseldorf
Authenticated | 93.180.53.211
Download Date | 11/7/13 10:43 PM