Methacryloyl-functional benzoxazine: Photopolymerization and thermally activated polymerization

Article abstract of DOI:10.1021/ma102351a

A novel class of photopolymerizable benzoxazines has been developed. This class has been coined as methacryloyl-functional benzoxazines. It has been synthesized by the reaction of the new benzoxazine monomers: (3-phenyl-3,4-dihydro-2H-benzo[e][1,3]oxazin-

Full text of DOI:10.1021/ma102351a

Macromolecules 2011, 44, 767–772 767
DOI: 10.1021/ma102351a
Methacryloyl-Functional Benzoxazine: Photopolymerization and
Thermally Activated Polymerization
Lin Jin,† Tarek Agag,† Yusuf Yagci,‡ and Hatsuo Ishida*,†
†Department of Macromolecular Science and Engineering Case Western Reserve University, Cleveland,
Ohio 44106-7202, United States, and ‡Department of Chemistry Istanbul Technical University, Istanbul, Turkey
Received July 6, 2010; Revised Manuscript Received January 6, 2011
ABSTRACT: A novel class of photopolymerizable benzoxazines has been developed. This class has been
coined as methacryloyl-functional benzoxazines. It has been synthesized by the reaction of the new
benzoxazine monomers: (3-phenyl-3,4-dihydro-2H-benzo[e][1,3]oxazin-6-yl)methanol and methacryloyl
chloride. The structure of the monomer has been confirmed by Fourier transform infrared spectroscopy
(FTIR) and 1H and 13C nuclear magnetic resonance spectroscopy (NMR). Its photopolymerization has been
successfully carried out with and without photoinitiator, while the thermally activated polymerization is
compromised by low temperature degradation.
1. Introduction
example, providing photochemically active groups are incorporated
into benzoxazine structure, sequential photochemical and thermal
activation would lead to the formation of network with higher
cross-linked density. This would obviously affect the Tg and conse-
quently mechanical properties of the resultant polymer. Addition-
ally, as the benzoxazine ring structure possesses two hetero atoms
and undergoes ring-opening reaction with Lewis acids such as
PCl5,23 the cationic photoinitiators may also be reactive to induce
polymerization.
Benzoxazine resin as a new class of high performance polymers
is gaining rapid interest in both academic and industrial fields. This
class of materials has many unique properties that allow it to
compete and replace traditional polymers in many applications.
Benzoxazine monomers can be synthesized from a phenolic deriva-
tive, formaldehyde, and a primary amine via Mannich reaction.
Benzoxazine monomers are typically polymerized through cationic
ring-opening polymerization. Benzoxazine monomers exhibit many
attractive properties, including low melt viscosity, no release of
volatiles during polymerization, and no need for harsh catalysts to
be added. Upon polymerization, a polymer with a phenolic hydro-
xyl group and a tertiary amine bridge as a repeating unit is produced.
In addition, the polymer is characterized by low volumetric shrink-
age upon polymerization; low moisture absorption; superb chemical
resistance, good flame retardance, excellent electrical properties,
high thermal stability and mechanical properties.1-5 Because of its
unique advantages, a number of papers have been published on
polybenzoxazines, which can be categorized into two main research
areas. The first area is related to the fundamental research aspects
for understanding the physical and chemical properties and their
relationship with the molecular structure.6-8 The second area is
to further improve the properties to meet specific applications as
high performance polybenzoxazines by introducing new functional
groups either by blending with monofunctional monomers and
difunctional monomers or as part of the monomer structure.9-18
This has also been extended to even main-chain benzoxazine
polymers that show outstanding performance than benzox-
azine monomers.19-21
To date, only a few studies on the photopolymerizable systems
containing benzoxazine have been reported. The photoinitiated
ring-opening cationic polymerization of neat phenol/aniline ben-
zoxazine monomer (P-a) and its application as hydrogen donors of
photoinitiated free radical polymerization for vinyl functionalized
compounds have been investigated by Kasapoglu et al.24,25
Recently, unsaturated polymerizable groups have been intro-
duced into benzoxazine as a potential photopolymerizable site. A
new bifunctional benzoxazine monomer containing coumarin26
has been reported being capable of undergoing photodimerization
and thermal ring-opening polymerization processes for curing
applications with highly dense cross-linked networks. The copo-
lymerization of styrene with the maleimide monomer functiona-
lized with benzoxazine and phenylnitrile has been studied. The
photoinitiated polymerization has been chosen to obtain linear
polymers with pendant thermolabile benzoxazine groups.27
Lately, Koz et al.28 prepared a methacryloyl-functional benzox-
azine monomer and did a simple investigation by copolymerizing
with styrene through thermally activated free radical polymeriza-
tion of benzoxazine. However, the incorporation of methacrylate
as a photopolymerizable functionality has not been investigated to
date. Therefore, to further extend the study, we have developed
new methacyloyl-benzoxazine-containing monomer and study its
photopolymerization behavior as well as thermal polymerization.
Photopolymerization is an elegant method in synthetic polymer
chemistry as it congregates a wide range of economic and ecological
anticipations.22 The reactions are more environmentally friendly as
they are typically operated without solvents. The reactions can be
controlled in both time and space. In contrast to thermally based
applications, which usually require elevated temperatures, photo-
polymerization can also be performed at room temperature and
below. When combined with thermally activated benzoxazine
polymerization, several additional advantages can be offered. For
2. Experimental Section
2.1. Materials. Aniline (99%), methacryloyl chloride (97%),
benzoyl peroxide (BPO), and dimethoxyphenyl acetophenone
(DMPA) (99%) were purchased from Aldrich Chemical Co..
4-Hydroxybenzyl alcohol was obtained from SAFC Supply Solu-
tions. Triethylamine, ethanol, chloroform, methylene chloride,
*Corresponding author. E-mail: hxi3@cwru.edu.
r 2011 American Chemical Society
Published on Web 01/26/2011
pubs.acs.org/Macromolecules

768 Macromolecules, Vol. 44, No. 4, 2011
Jin et al.
toluene, paraformaldehyde, sodium hydroxide, and sodium
sulfate anhydrous (99%) were obtained from Fisher Scientific Co.
Benzoyl peroxide was recrystallized from chloroform:ethanol (1:1)
mixture. All the other chemicals were used as received.
2.2. Preparation of Vinylester-Functional Benzoxazine Mono-
mers. 2.2.1. Preparation of (3-Phenyl-3,4-dihydro-2H-benzo[e]-
[1,3]oxazin-6-yl)methanol (HBA-a). Into a 50 mL flask were
added aniline (1.86 g, 20 mmol), 4-hydroxybenzyl alcohol (HBA)
(2.48 g, 20 mmol) and paraformaldehyde (1.2 g, 40 mmol) with a
mole ratio of 1:1:2 and toluene (30 mL) were added and stirred at
100 °C for 8 h. The solution was allowed to cool to room tempera-
ture. The solid residue was collected by filtration and recrystallized
using toluene to afford pale yellow crystals of HBA-a (85%).
1H NMR (CDCl3, ppm, δ): 4.55(s, Ar-CH2-OH), 4.64 (s, C-
CH2-N-), 5.44 (s, N-CH2-O-), 6.75-7.27(m, Ar).
13C NMR (CDCl3, ppm, δ): 50.83 (C-CH2-N-), 65.31
(Ar-CH2-OH), 79.91 (N-CH2-O-).
IR (KBr, cm-1): 3092-3625 (-OH stretching), 945 (out-
of-plane C-H).
2.2.2. Preparation of (3-Phenyl-3,4-dihydro-2H-benzo[e][1,3]oxa-
zin-6-yl)methyl Methacrylate. In a 100 mL flask, HBA-a (2.41 g,
10 mmol) was dissolved in methylene chloride, followed by adding
triethylamine (1.52 g, 15 mmol) and methacryloyl chloride (1.57 g,
15 mmol). The solution was stirred for 2 h at room temperature,
followed by washing with sodium hydroxide aqueous solution
(0.5M, 25 mL Â 3) and drying over sodium sulfate anhydrous.
Yellowish crystals were obtained after evaporating solvent (90%).
1H NMR (CDCl3, ppm, δ): 1.95 (s, CdC-CH3), 4.63 (s,
C-CH2-N-), 5.07 (s, Ar-CH2-OH), 5.36 (s, N-CH2-O-),
5.56 (s, CdCH2), 6.11 (s, CdCH2), 6.78-7.28(m, Ar).
Figure 1. 1H NMR spectra of methacryloyl-benzoxazine monomer
(3-phenyl-3,4-dihydro-2H-benzo[e][1,3]oxazin-6-yl)methyl methacry-
late and its raw materials.
Scheme 1. Preparation of Methacryloyl-Benzoxazine Monomer (3-
Phenyl-3,4-dihydro-2H-benzo[e][1,3]oxazin-6-yl)methyl Methacrylate
13C NMR (CDCl3, ppm, δ): 18.37 (C-CH3), 50.48 (C-CH2-
N-), 66.18 (Ar-CH2-O), 79.45 (N-CH2-O-), 128.27 (Cd
C*H2), 136.22 (CH3-C*dCH2), 167.27 (O-CdO).
IR (KBr, cm-1): 1715 (CdO), 1637 (CdC), 945 (out-of-plane
C-H).
2.3. Thermally-Activated Polymerization of (3-Phenyl-3,4-di-
hydro-2H-benzo[e][1,3]oxazin-6-yl)methyl Methacrylate. A solution
of the monomer in CHCl3 was prepared. Then, the solution was cast
over dichlorodimethylsilane-pretreated glass plates. The films as
fixed on glass plates were heated stepwise at 100, 140, 180, and
200 °C for 1 h each and then slowly cooled to room temperature.
1% BPO was added to the monomer and the solution was cast as a
thin film on a KBr plate. The sample was heated at 70 °C for 1, 2, 4,
and 23 h. FTIR spectra were taken at each heating period.
2.4. Photopolymerization of (3-Phenyl-3,4-dihydro-2H-benzo-
[e][1,3]oxazin-6-yl)methyl Methacrylate. (3-Phenyl-3,4-dihydro-
2H-benzo[e][1,3]oxazin-6-yl)methyl Methacrylate with and without
5% DMPA were dissolved in chloroform and cast as thin films on
KBr plates. The film was exposed to UV light for up to 1 min for
FTIR investigation. The monomer films were also made on poly-
(ethylene terephthalate) (PET) film, which was covered by poly-
propylene (PP) film and underwent up to 5 min UV exposure.
2.4. Measurements. 1H and 13C NMR spectra were acquired
in deuterated chloroform on a Varian Oxford AS600 at a
proton frequency of 600 MHz and its corresponding carbon
frequency of 150.9 MHz. The average number of transients for
1H and 13C is 64 and 1024, respectively. A relaxation time of 10s
was used for the integrated intensity determination of 1H
NMR spectra. Fourier transform infrared (FTIR) spectra were
obtained using a Bomem Michelson MB100 FTIR spectro-
meter, which was equipped with a deuterated triglycine sulfate
(DTGS) detector and a dry air purge unit. Coaddtion of
32 scans was recorded at a resolution of 4 cm-1. Transmission
spectra were obtained by casting a thin film on a KBr plate for
partially cured samples.
3. Results and Discussion
3.1. Preparation of (3-Phenyl-3,4-dihydro-2H-benzo[e]-
[1,3]oxazin-6-yl)methyl Methacrylate. The novel monomer
(3-phenyl-3,4-dihydro-2H-benzo[e][1,3]oxazin-6-yl)methyl
methacrylate, comprising of both benzoxazine and metha-
crylate moieties, was prepared by the reaction of HBA and
methacroyl chloride, as shown in Scheme 1.
The chemical structure of the monomer was confirmed by
1H NMR, 13C NMR, and FT-IR. Figure 1 shows the 1H NMR
spectra of (3-phenyl-3,4-dihydro-2H-benzo[e][1,3]oxazin-6-yl)-
methyl methacrylate and its original reactants: (3-phenyl-3,4-
dihydro-2H-benzo[e][1,3]oxazin-6-yl)methanol and methacry-
loyl chloride.
The peak at 1.95 ppm is assigned to the protons of CH3 of
methacrylate group. The characteristic proton resonances of the
oxazine ring for the product appear as two singlets with equal
integrated intensity at 4.63 and 5.36 ppm, which are assigned to
Ar-CH2*-N- and -O-CH2*-N-, respectively. The singlet
at 5.07 ppm is attributed to -CH2*-O-CdO, which has a
dramatic shift from 4.55 ppm as -CH2*-OH of (3-phenyl-3,4-
dihydro-2H-benzo[e][1,3]oxazin-6-yl)methanol. The two sing-
lets at 5.56 and 6.11 ppm are assigned to the vinyl protons of
CH3-CdCH2*, showing a shift from 6.05 and 6.51 ppm from
methacryloyl chloride structure. The splitting of vinyl proton
A differential scanning calorimeter (DSC), TA Instruments
DSC model 2920, was used with heating rate of 10 °C/min and a
nitrogen flow rate of 60 mL/min for all tests. All samples were
crimped in hermetic aluminum pans with lids. The UV source
used was 100 W with output from 200 nm to 2.5 μm by Newport.

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Macromolecules, Vol. 44, No. 4, 2011 769
Figure 2. 13C NMR spectra of vinylester benzoxazine monomer
(3-phenyl-3,4-dihydro-2H-benzo[e][1,3]oxazin-6-yl)methyl methacrylate
and its raw materials. A small amount of impurities present in the original
methacryloyl chloride is excluded during the purification procedure of
the benzoxazine.
resonance is because the conjugation of carbonyl and vinyl
group limits the bond mobility and makes the two protons
surrounded by different chemical environments. The multiplet
in the range 6.78-7.28 ppm is assigned to the protons of the
aromatic ring.
Figure 2 shows the 13C NMR spectra for the monomers.
The peak at 18.37 ppm is assigned to the CH3 carbons in the
methacrylate moiety. The characteristic carbon resonances of
the oxazine ring appear at 50.48 ppm for C-C*H2-N- and at
79.45 ppm for N-C*H2-O-, respectively. The resonance at
66.18 ppm is from Ar-C*H2-OCO. The peaks at 128.27,
136.22, and 167.27 ppm are attributed to the CH*2dC-CdO,
CH2dC*-CdO and CH2dC-C*dO, respectively.
The IR spectrum shown at the bottom in Figure 3 is the
monomer itself. It exhibits the typical stretching absorption of
Figure 3. FTIR spectra of methacryloyl-benzoxazine monomer (3-phe-
nyl-3,4-dihydro-2H-benzo[e][1,3]oxazin-6-yl)methyl methacrylate and
methylol-benzoxazine (3-phenyl-3,4-dihydro-2H-benzo[e][1,3]oxazin-6-yl)-
methanol.
the carbonyl in the methyl methacrylate structure at 1715 cm-1
.
It is known that the band from 1650 to 1600 cm-1 is assigned to
the CdC stretching mode. By comparing the spectrum of
methacryloyl-benzoxazine with that of hydroxymethyl-benzox-
azine shown in Figure 3, it is concluded that the multiple peaks
from 1628 to 1560 cm-1 are due to the CdC stretching modes of
aromatic rings and the peak at 1637 cm-1 is originated from the
CdC stretching of the vinyl structure. These assignments are
consistent with the literature.29
This band at 1637 cm-1 is used to follow the polymerization
of the vinyl group. For the benzoxazine structure, the charac-
teristic band at 945 cm-1 due to the out-of-plane C-Hvibration
of the benzene ring to which the oxazine ring is attached is
observed.
DSC thermogram of the monomer is shown at the bottom
in Figure 4.
One exotherm is observed with the onset of the peak around
193 °C. The exothermic maximum is seen at 203 °C with the total
heat of polymerization of 315 J/g. It is expected that both ben-
zoxazine ring-openning polymerization and methacrylate free-
radical polymerization happen in the range of the exotherm and
it will be further explained in the following discussion.
3.2. Polymerization Behavior of (3-Phenyl-3,4-dihydro-2H-
benzo[e][1,3]oxazin-6-yl)methyl Methacrylate. 3.2.1. Polymer-
ization by Heating. The polymerization behavior of (3-phenyl-
3,4-dihydro-2H-benzo[e][1,3]oxazin-6-yl)methyl methacrylate
Figure 4. DSC curves of methacryloyl-benzoxazine monomer (3-phe-
nyl-3,4-dihydro-2H-benzo[e][1,3]oxazin-6-yl)methyl methacrylate after
each heating stage.

770 Macromolecules, Vol. 44, No. 4, 2011
Jin et al.
Figure 6. TGA curve of methacryloyl-benzoxazine monomer (3-phen-
yl-3,4-dihydro-2H-benzo[e][1,3]oxazin-6-yl)methyl methacrylate.
Figure 5. FTIR spectra of vinylester benzoxazine monomer (3-phenyl-
3,4-dihydro-2H-benzo[e][1,3]oxazin-6-yl)methyl methacrylate after each
heating stage.
was studied by DSC by stepwise heating at 100, 140, 180, and
200 °C for 1 h each. The result is shown in Figure 4. The
monomer itself shows one exothermic peak with one shoulder at
lower temperature side. The exotherm maximized at 203 °Cwith
the total heat of polymerization of 315 J/g for the unheated
sample. With increasing severity of heat treatment, the residual
heat of polymerization expectedly decreases to 209, 148, and 14
J/g for 100, 140, and 180 °C treatment, respectively. Meanwhile,
the peak moves to higher temperature and two separated peaks
are observed for the 100 °C treatment. No exothermic event is
seen for the 200 °C treatment, indicating that the polymerization
is complete.
The polymerization behavior is also monitored by FTIR
after each heat treatment, as shown in Figure 5. A broad
peak around 3400 cm-1 appears and rest of the peaks
decrease after the 100 °C treatment. After the 140 °C stage,
the peaks start to show substantial decrease. This phenom-
enon has not been observed for any other benzoxazine in
literature. It is presumed that, by incorporating acrylate
chemistry into the benzoxazine, the decompositition at lower
temperature has happened.
Figure 7. FTIR spectra of methacryloyl-benzoxazine monomer
(3-phenyl-3,4-dihydro-2H-benzo[e][1,3]oxazin-6-yl)methyl methacrylate
with 1% benzoyl peroxide isothermal at 70 °C.
This is confirmed by the TGA result of the monomer as
shown in Figure 6. A sharp peak for derivative weight at 195 °C
and about 12% weight loss after the peak is observed. It is
believed that CH2-O-CdO linkage in the monomer structure
is a weak portion and, upon heating, the chain breaks, as benzyl
ether was used as a good leaving group of protected hy-
droxyl groups.30,31 This process produces the benzoxazine with
methylol structure, which could undergo the condensation poly-
merization into phenolic resins, and methacrylic acid as one
unstable small molecule, which results in the significant intensity
decrease for carbonyl band at 1715 cm-1. The band at 3400
cm-1 is attributed to the -OH in the ring-opened polybenzox-
azine structure and the -CH2OH after chain scission. The
complicated thermal behavior at this stage explains the shoulder
of the exotherm in DSC thermogram. Besides, relatively ther-
mally unstable MMA (methyl methacrylate) segment may
contribute to create porosity on the networks prepared from
the low molar mass benzoxazines with PMMA-Bz by the con-
trolled thermal degradation. This approach was previously
reported in the literature through the basic degradation of poly-
caprolactone in related benzoxazine systems in order to reduce
the dielectric constant of the resultant polymer.32
In order to fully polymerize the monomer, the acrylate por-
tion should be first polymerized to anchor it into the network
structure. On the basis of this hypothesis, free radical initiator,
benzoyl peroxide (BPO), was added into the monomer at 70 °C
to help acrylate polymerize at lower temperature before decom-
position. FTIR is used to investigate the change of the molecular
structure under the heat treatment, and the result is shown in
Figure 7. It can be seen that, even under mild condition at 70 °C,
the decomposition is still happening, which is indicated by
the significant decrease in intensity of the carbonyl band at
1715 cm-1. Therefore, it appears that the monomer is relatively
sensitive to heat, and at least some part of the molecule will
undergo decomposition before its polymerization.
3.2.2. Photopolymerization Behavior. Because of the diffi-
culty of polymerizing the monomer by heating, a different
approach was taken to polymerize the acrylate portion at
room temperature by photoinitiated free-radical polymeri-
zation. Photopolymerization of vinylester, vinyl acrylate,
and divinyl fumarate has been extensively investigated by
researchers.33,34 On the basis of the previous knowledge, the
photopolymerization of (3-phenyl-3,4-dihydro-2H-benzo-
[e][1,3]oxazin-6-yl)methyl methacrylate was conducted by

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Macromolecules, Vol. 44, No. 4, 2011 771
Figure 10. DSC thermograms ofmethacryloyl-benzoxazine monomer
after 1 min UV irradiation.
Figure 8. FTIR spectra of methacryloyl-benzoxazine monomer (3-phenyl-
3,4-dihydro-2H-benzo[e][1,3]oxazin-6-yl)methyl methacrylate exposed
under UV irradiation at room temperature.
the initiator during the experimental process. It is known that
vinyl acrylate monomer can be used as the photoinitiating
monomer,35 and by adding a photo initiator, a higher extent
of the polymerization can be achieved. Ordinary benzoxazines
do not polymerize under UV in such small time scale. However,
the slight decrease of the benzoxazine-related band at 945 cm-1
due to the out-of-plane C-H vibration is observed. Both with
and without the initiator monomer show the same trend and
achieve about 10% decrease of benzoxazine ring at 1 min. An
increase in the band intensity between 3600 and 3300 cm-1 is
believed to come from hydroxyl group from ring-opening
polymerized structure of benzoxazine as there is no indication
for loss of carbonyl groups from degradation. This shows that
the presence of methacrylate structure expedite the polymeri-
zation of benzoxazine under UV exposure.
The DSC thermogram after the photopolymerization for
1 min shown in Figure 10 indicates one exotherm maximized at
222 °C, reflecting the increased rigidity in surrounding environ-
ment due to the polymer chain formation and cross-linking.
Besides, the heat of the exotherm is much smaller compared
with that of room temperature, as the room temperature DSC
shows the exotherm for methacrylate polymerization, benzox-
azine polymerization and degradation. The cross-linking of
benzoxazine could be due to hydrogen abstraction from carbon
atom adjacent to the nitrogen atom or from the methyl group in
the vinyl. Owing to this H abstraction, new free radical species
has been generated that result in two reacting sites in one
molecule. This hypothesis explains the insolubility of the photo-
polymerized monofunctional benzoxazine despite the fact there
is only one vinyl group in each molecule.
To further compare the difference among the three polymeri-
zation approaches, the difference spectra were generated using
one example from each method as shown in Figure 11. In the
difference spectra, the band above the baseline means it in-
creases in concentration with the process, while the peak below
the baseline indicates the decrease. One characteristic peak is the
antisymmetric stretching absorption of the carbonyl group at
1715 cm-1. The peak becomes smaller by the thermal treatment
both with and without the free-radical initiator, while it shifts to
higher wavenumber without decreasing by the irradiation
process. Since the extinction coefficient of the carbonyl group
before and after the polymerization is expected to be nearly
identical, having nearly equal intensity above and below the
baseline of the carbonyl band indicates the structural change by
Figure 9. FTIR conversion vs time plots of methacryloyl-benzoxazine
monomer (3-phenyl-3,4-dihydro-2H-benzo[e][1,3]oxazin-6-yl)methyl
methacrylate or in the presence of 5% DMPA exposed under UV
irradiation at room temperature.
exposing the monomer film both with and without a photo-
initiator, dimethoxyphenyl acetophenone (DMPA), under
the UV light from 5 to 60 s. The corresponding FTIR spectra
for the monomer without the initiator as an example are
shown in Figure 8.
Instead of dramatic decrease in intensity, the frequency of
the carbonyl band gradually shifted from 1715 to 1720 cm-1
because of the loss of conjugation by the vinyl polymeriza-
tion. The intensity change of the peak at 1637 cm-1 is used to
calculate the photopolymerization conversion of the double
bond and the peak at 945 cm-1 is used to demonstrate the
change of benzoxazine ring during the UV exposure. These
are illustrated in Figure 9.
For vinyl polymerization, the monomer with and without
the initiator shows a similar trend as a dramatic increase of
conversion in 5 s and gradually reaches the asymptotic value
in 1 min. The one with the initiator shows an increase of
additional 10% conversion compared with the one without

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the polymerization rather than degradation. Moreover, the
,
intensity increase of the bands between 3000 and 2800 cm-1
which are attributed to the C-H stretching modes from
saturated C-H bonds, is observed only in photopolymerization
approach. This indicates the success of converting the double
bond in acrylate moiety into aliphatic chains. Overall, it is
demonstrated that photopolymerization is feasible to anchor
the acrylate in the monomer in spite of the difficulty experienced
with free radical polymerization with and without an initiator.
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4. Conclusion
We have synthesized a novel methacryloyl-functional benzox-
azines: (3-phenyl-3,4-dihydro-2H-benzo[e][1,3]oxazin-6-yl)methyl
methacrylate by the reaction of (3-phenyl-3,4-dihydro-2H-benzo-
[e][1,3]oxazin-6-yl)methanolandmethacryloyl chloride. It has been
successfully photopolymerized with and without photoinitiator to
extend the application of the material curable at ambient condi-
tions. Its thermally activated polymerization is deteriorated by its
degradation at low temperature of 200 °C.
ꢀ
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