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1.
Novel copolymers of trisubstituted ethylene monomers, ring-substituted 2-phenyl-1,1-dicyanoethylenes, RC6H3CH═C(CN)2 (where R is 2-bromo,3-bromo, 3-chloro, 2,3-dichloro, 2-chloro-6-fluoro, 2,6-difluoro, 3,4-difluoro, and 3,5-difluoro) and styrene were prepared at equimolar monomer feed composition by solution copolymerization in the presence of a radical initiator (AIBN) at 70°C. The composition of the copolymers was calculated from nitrogen analysis, and the structures were analyzed by IR, 1H and 13C-NMR, GPC, DSC, and TGA. High T g of the copolymers in comparison with that of polystyrene indicates a substantial decrease in chain mobility of the copolymer due to the high dipolar character of the trisubstituted ethylene monomer unit. The gravimetric analysis indicated that the copolymers decompose in the 200–800°C range.  相似文献   

2.
Novel copolymers of trisubstituted ethylene monomers, alkyl and alkoxy ring-substituted 2-phenyl-1,1-dicyanoethylenes, RC6H4CH=C(CN)2 (where R is 2-ethyl, 4-i-propyl, 4-butyl, 4-i-butyl, 4-t-butyl, 2-ethoxy, and 4-hexyloxy) and styrene were prepared at equimolar monomer feed composition by solution copolymerization in the presence of a radical initiator (ABCN) at 70°C. The composition of the copolymers was calculated from nitrogen analysis, and the structures were analyzed by IR, 1H and 13C-NMR. The order of relative reactivity (1/r 1) for the monomers is 4-t-butyl (1.45) > 4-i-propyl (1.38) > 2-ethyl (1.37) > 4-hexyloxy (1.33) > 4-i-butyl (1.24) > 2-ethoxy (1.13) > 4-butyl (1.04). High T g of the copolymers, in comparison with that of polystyrene) indicates a substantial decrease in chain mobility of the copolymer due to the high dipolar character of the trisubstituted ethylene monomer unit. Decomposition of the copolymers in nitrogen occurred in two steps, first in the 200–500°C range with residue (1–10% wt.), which then decomposed in the 500–800°C range.  相似文献   

3.
Novel copolymers of trisubstituted ethylene monomers, ring-substituted 2-phenyl-1,1-dicyanoethylenes, RC6H2CH=C(CN)2 (where R is 4-C6H5O, 2-C6H5CH2O, 3,4-(C6H5CH2O)2, 2-C6H5CH2O-3-CH3O, 3-C6H5CH2O-4-CH3O, 2-Cl-6-NO2, 4-Cl-3-NO2, 5-Cl-2-NO2) and 4-fluorostyrene were prepared at equimolar monomer feed composition by solution copolymerization in the presence of a radical initiator (ABCN) at 70°C. The composition of the copolymers was calculated from nitrogen analysis, and the structures were analyzed by IR, 1H and 13C-NMR. The order of relative reactivity (1/r 1) for the monomers is 3,4-(C6H5CH2O)2(31.0) > 2-C6H5CH2O-3-CH3O (24.8) > 3-C6H5CH2O-4-CH3O (15.2) > 4-C6H5O (3.1) > 4-Cl-3-NO2 (1.9) > 2-Cl-6-NO2 (1.6) > 5-Cl-2-NO2 (1.5) > 2-C6H5CH2O (1.4). High Tg of the copolymers, in comparison with that of poly(4-fluorostyrene) indicates a substantial decrease in chain mobility of the copolymer due to the high dipolar character of the trisubstituted ethylene monomer unit. Decomposition of the copolymers in nitrogen occurred in two steps, first in the 270-400°C range with residue, which then decomposition in 400–800°C range.  相似文献   

4.
Novel copolymers of trisubstituted ethylene monomers, ring-substituted 2-phenyl-1,1-dicyanoethylenes, RC6H2CH=C(CN)2 (where R is 2,4-(CH3O)2-3-CH3, 2,3,4-(CH3O)3, 2,4,5-(CH3O)3, 2,4,6-(CH3O)3, 3,4,5-(CH3O)3, 6-Br-3,4-(CH3O)2), 2,3,5-Cl3, 2,3,6-Cl3 and 4-fluorostyrene were prepared at equimolar monomer feed composition by solution copolymerization in the presence of a radical initiator (ABCN) at 70°C. The composition of the copolymers was calculated from nitrogen analysis, and the structures were analyzed by IR, 1H and 13C-NMR. The order of relative reactivity (1/r 1) for the monomers is 3,4,5-(CH3O)3(10.6) > 2,4,6-(CH3O)3(9.3) > 2,4,5-(CH3O)3 (5.4) > 2,3,4-(CH3O)3 (4.4) > 6-Br-3,4-(CH3O)2 (3.2) > 2,3,5-Cl3 (1.5) > 2,3,6-Cl3 (1.0) > 2,4-(CH3O)2-3-CH3 (0.7). High T g of the copolymers, in comparison with that of poly(4-fluorostyrene) indicates a substantial decrease in chain mobility of the copolymer due to the high dipolar character of the trisubstituted ethylene monomer unit. Decomposition of the copolymers in nitrogen occurred in two steps, first in the 200–400°C range with residue, which then decomposed in the 400–800°C range.  相似文献   

5.
Novel copolymers of trisubstituted ethylene monomers, ring-substituted 2-phenyl-1,1-dicyanoethylenes, RC6H4CH=C(CN)2 (where R is 4-dimethylamino, 4-diethylamino, 3-phenoxy, 3-benzyloxy, 4-benzyloxy, 4-acetoxy, 2-cyano, 3-cyano, and 4-cyano) and 4-fluorostyrene were prepared at equimolar monomer feed composition by solution copolymerization in the presence of a radical initiator (ABCN) at 70°C. The composition of the copolymers was calculated from nitrogen analysis, and the structures were analyzed by IR, 1H and 13C-NMR. The order of relative reactivity (1/r 1) for the monomers is 3-benzyloxy (2.9) > 4-cyano (2.7) > 3-phenoxy (1.9) > 4-acetoxy (1.8) > 3-cyano (1.7) > 2-cyano (1.6) > 4-benzyloxy (0.6) > 4-dimethylamino (0.4) = 4-diethylamino (0.4). High T g of the copolymers, in comparison with that of poly (4-fluorostyrene) indicates a substantial decrease in chain mobility of the copolymer due to the high dipolar character of the trisubstituted ethylene monomer unit. Decomposition of the copolymers in nitrogen occurred in two steps, first in the 290–400°C range with residue, which then decomposition in 400–800°C range.  相似文献   

6.
Novel copolymers of trisubstituted ethylene monomers, ring-disubstituted 2-phenyl-1,1-dicyanoethylenes, RC6H3CH=C(CN)2 (where R = 3-Br-4-CH3O, 5-Br-2-CH3O, 2-F-5-CH3, 2-F-6-CH3, 3-F-2-CH3, 3-F-4-CH3, 4-F-2-CH3, 4-F-3-CH3) and 4-fluorostyrene were prepared at equimolar monomer feed composition by solution copolymerization in the presence of a radical initiator (ABCN) at 70°C. The composition of the copolymers was calculated from nitrogen analysis, and the structures were analyzed by IR, 1H and 13C-NMR. The order of relative reactivity (1/r 1) for the monomers is 3-F-4-CH3(1.64) > 5-Br-2-CH3O (1.62) > 3-Br-4-CH3O (1.36) > 4-F-2-CH3(1.3) > 4-F-3-CH3(1.26) > 3-F-2-CH3(1.11) > 2-F-5-CH3 (0.98) > 2-F-6-CH3 (0.97). High Tg of the copolymers, in comparison with that of poly(4-fluorostyrene) indicates a substantial decrease in chain mobility of the copolymer due to the high dipolar character of the trisubstituted ethylene monomer unit. Decomposition of the copolymers in nitrogen occurred in two steps, first in the 290–400°C range with residue, which then decomposed in 400–800°C range.  相似文献   

7.
Electrophilic trisubstituted ethylenes, ring-disubstituted ethyl 2-cyano-3-phenyl-2-propenoates, RPhCH?C(CN)CO2C2H5 (where R is 3-Br-4-CH3O, 5-Br-2-CH3O, 3-F-2- CH3, 3-F-4-CH3, 4-F-2-CH3, 4-F-3-CH3, 5-F-2-CH3, 2-Cl-5-NO2, 2-Cl-6-NO2, 4-Cl-3- NO2) were prepared and copolymerized with styrene. The monomers were synthesized by the piperidine catalyzed Knoevenagel condensation of ring-disubstituted benzaldehydes and ethyl cyanoacetate, and characterized by CHN analysis, IR, 1H and 13C-NMR. All the ethylenes were copolymerized with styrene (M1) in solution with radical initiation (ABCN) at 70°C. The composition of the copolymers was calculated from nitrogen analysis, and the structures were analyzed by IR, 1H and 13C-NMR. The order of relative reactivity (1/r 1) for the monomers is 5-Br-2-CH3O (1.02) > 4-Cl-3-NO2 (0.93) > 3-F-4-CH3 (0.81) > 2-Cl-6-NO2 (0.77) > 2-Cl-5-NO2 (0.71) > 3-Br-4-CH3O (0.66) > 4-F-3-CH3 (0.60) > 3-F-2-CH3 (0.38) > 4-F-2-CH3 (0.31) > 5-F-2-CH3 (0.16). Relatively high Tg of the copolymers in comparison with that of polystyrene indicates a decrease in chain mobility of the copolymer due to the high dipolar character of the trisubstituted ethylene monomer unit. Decomposition of the copolymers in nitrogen occurred in two steps, first in the 250–500°C range with residue (2–26% wt.), which then decomposed in the 500–800°C range.  相似文献   

8.
Novel trisubstituted ethylenes, ring-substituted butyl 2-cyano-3-phenyl-2-propenoates, RPhCH=C(CN)CO2C4H9 (where R is 2-C6H5CH2O, 3-C6H5CH2O, 4-C6H5CH2O, 4-CH3COO, 3-CH3CO, 4-CH3CO, 4-CH3CONH, 2-CN, 3-CN, 4-CN, 4-(CH3)2N, 4-(C2H5)2N) were prepared and copolymerized with styrene. The monomers were synthesized by the piperidine catalyzed Knoevenagel condensation of ring-substituted benzaldehydes and butyl cyanoacetate, and characterized by CHN analysis, IR, 1H and 13C-NMR. All the ethylenes were copolymerized with styrene (M1) in solution with radical initiation (ABCN) at 70°C. The compositions of the copolymers were calculated from nitrogen analysis and the structures were analyzed by IR, 1H and 13C-NMR. The order of relative reactivity (1/r1) for the monomers is 4-C6H5CH2O (6.39) > 2-C6H5CH2O (2.06) > 3-CH3CO (1.86) > 3-C6H5CH2O (1.78) > 4-CH3COO (1.58) > 3-CN (1.47) > 4-CN (1.21) > 4-(C2H5)2N (1.19) > 4-(CH3)2N (1.18) > 2-CN (1.04) > 4-CH3CO (0.71) > 4-CH3CONH (0.63). Decomposition of the copolymers in nitrogen occurred in two steps, first in the 200–500°C range with residue (3.6–9.5% wt), which then decomposed in the 500–800°C range.  相似文献   

9.
Novel trisubstituted ethylenes, oxy ring-disubstituted butyl 2-cyano-3-phenyl-2-propenoates, RPhCH=C(CN)CO2C4H9 (where R is 4-methoxy-2-methyl, 4-methoxy-3-methyl, 3-ethoxy-4-methoxy, 4-ethoxy-3-methoxy, 3,4-dibenzyloxy, 2-benzyloxy-3-methoxy, and 3-benzyloxy-4-methoxy) were prepared and copolymerized with styrene. The monomers were synthesized by the piperidine catalyzed Knoevenagel condensation of ring-substituted benzaldehydes and butyl cyanoacetate, and characterized by CHN analysis, IR, 1H and 13C-NMR. All the ethylenes were copolymerized with styrene (M1) in solution with radical initiation (ABCN) at 70°C. The compositions of the copolymers were calculated from nitrogen analysis and the structures were analyzed by IR, 1H and 13C-NMR.

Decomposition of the copolymers in nitrogen occurred in two steps, first in the 200-500°C range with residue (2-17 % wt.), which then decomposed in the 500-800°C range.  相似文献   

10.
Novel copolymers of trisubstituted ethylene monomers, alkoxy ring-substituted 2-phenyl-1,1-dicyanoethylenes, RC6H4CH = C(CN)2 (where R is 2-methoxy, 3-methoxy, 4-methoxy, 2-ethoxy, 3-ethoxy, 4-ethoxy, 4-propoxy, 4-buthoxy, 4-hexyloxy) and 4-fluorostyrene were prepared at equimolar monomer feed composition by solution copolymerization in the presence of a radical initiator (ABCN) at 70°C. The composition of the copolymers was calculated from nitrogen analysis, and the structures were analyzed by IR, 1H and 13C-NMR. The order of relative reactivity (1/r 1) for the monomers is 2-methoxy (1.5) > 4-ethoxy (1.0) > 4-methoxy (0.8) > 3-ethoxy (0.7) = 3-methoxy (0.7) > 4-hexyloxy (0.6) = 2-ethoxy (0.6) > 4-butoxy (0.5) = 4-propoxy (0.5). High T g of the copolymers, in comparison with that of poly(4-fluorostyrene) indicates a substantial decrease in chain mobility of the copolymer due to the high dipolar character of the trisubstituted ethylene monomer unit. Decomposition of the copolymers in nitrogen occurred in two steps, first in 284–500°C range with residue (5–9% wt), which then decomposed in the 500–800°C range.  相似文献   

11.
Copolymerization of fluorine ring-substituted 2-phenyl-1,1-dicyanoethenes, RC6H3CH?C(CN)2 (R is 2,3-F,F, 2,4-F,F, 2,5-F,F, 2,6-F,F, and 4-CF3) with 4-fluorostyrene were prepared in the presence of a radical initiator (ABCN) at 70°C. The composition of the copolymers was calculated from nitrogen analysis, and the copolymers were characterized by IR, 1H and 13C-NMR, GPC, DSC, and TGA. The monomer reactivity ratios for 4-fluorostyrene (M1), r1 = 0.6 and 2-(2,4-difluorophenyl)-1,1-dicyanoethene (M2), r2 = 0 were determined from Fineman-Ross plot. The order of relative reactivity (1/r1) for difluoro-substituted monomers is 2,4-F,F (0.31) > 2,3-F,F (0.25) > 2,5-F,F (0.22) > 2,6-F,F (0.10). DSC curves showed that the copolymers were amorphous with high T g in comparison with that poly(4-fluorostyrene) indicating a substantial decrease in chain mobility of the copolymer due to the high dipolar character of the trisubstituted ethylene monomer units. From the thermogravimetric analysis, the copolymers began to degrade in the range 214–260°C. The copolymer of 4-fluorostyrene and 2-(2,4-difluorophenyl)-1,1-dicyanoethene and poly(4-fluorostyrene) were dielectrically characterized in the range 25–200°C. The dominating relaxation process detected in both materials was the α-relaxation, associated with the dynamic glass transition. The relationship polarity-permittivity was discussed.  相似文献   

12.
Novel copolymers of trisubstituted ethylene monomers, alkyl ring-substituted 2-phenyl-1,1-dicyanoethylenes, RC6H4CH = C(CN)2 (where R is 2-methyl, 3-methyl, 4-methyl, 4-ethyl, 4-i-propyl, 4-butyl, 4-i-butyl, and 4-t-butyl) and 4-fluorostyrene were prepared at equimolar monomer feed composition by solution copolymerization in the presence of a radical initiator (ABCN) at 70°C. The composition of the copolymers was calculated from nitrogen analysis, and the structures were analyzed by IR, 1H and 13C-NMR. The order of relative reactivity (1/r 1) for the monomers is 4-ethyl (42.6) > 4-butyl (29.4) > 4-t-butyl (26.7) > 4-i-butyl (1.6) > 4-i-propyl (1.29) > 3-methyl (1.26) > 2-methyl (0.8) > 4-methyl (0.4). High T g of the copolymers, in comparison with that of poly(4-fluorostyrene) indicates a substantial decrease in chain mobility of the copolymer due to the high dipolar character of the trisubstituted ethylene monomer unit. Decomposition of the copolymers in nitrogen occurred in two steps, first in 183–500°C range with residue (5–30% wt.), which then decomposed in the 500–800°C range.  相似文献   

13.
Novel copolymers of trisubstituted ethylene monomers, halogen ring-disubstituted 2-phenyl-1,1-dicyanoethylenes, RC6H3CH= C(CN)2 (where R is 2,3-Cl2, 2,4-Cl2, 2,6-Cl2, 3,4-Cl2, 3,5-Cl2, 2-Cl-4-F, 2-Cl-6-F, 3-Cl-4-F) and 4-fluorostyrene were prepared at equimolar monomer feed composition by solution copolymerization in the presence of a radical initiator (ABCN) at 70°C. The composition of the copolymers was calculated from nitrogen analysis, and the structures were analyzed by IR, 1H and 13C-NMR. The order of relative reactivity (1/r 1) for the monomers is 2-Cl-4-F (2.42) > 3,4-Cl2(2.40) > 2,4-Cl2(1.97) > 2-Cl-6-F (1.86) > 3-Cl-4-F (1.68) > 2,3-Cl2 (0.89) > 3,5-Cl2 (0.70) > 2,6-Cl2 (0.47). High Tg of the copolymers, in comparison with that of poly(4-fluorostyrene) indicates a substantial decrease in chain mobility of the copolymer due to the high dipolar character of the trisubstituted ethylene monomer unit. Softening of the copolymers started in 194–216°C range. Decomposition of the copolymers in nitrogen occurred in two steps, first in the 290–400°C range with residue, which then decomposed in 400–800°C range.  相似文献   

14.
Electrophilic trisubstituted ethylenes, dihalogen ring-substituted ethyl 2-cyano-3-phenyl-2-propenoates, RPhCH?C(CN)CO2C2H5 (where R is 2,3-diCl, 2,4-diCl, 2,6-diCl, 3,4-diCl, 3,5-diCl, 2,3-diF, 2,4-diF, 2,5-diF, 2,6-diF, 3,4-diF, 3,5-diF) were prepared and copolymerized with styrene. The monomers were synthesized by the piperidine catalyzed Knoevenagel condensation of ring-substituted benzaldehydes and ethyl cyanoacetate, and characterized by CHN analysis, IR, 1H and 13C-NMR. All the ethylenes were copolymerized with styrene (M1) in solution with radical initiation (ABCN) at 70°C. The composition of the copolymers was calculated from nitrogen analysis, and the structures were analyzed by IR, 1H and 13C-NMR. The order of relative reactivity (1/r 1) for the monomers is 3,4-diCl (1.89) > 2,4-diCl (1.84) > 3,5-diCl (1.40) > 2,6-diCl (1.21) > 2,4-diF (1.16) > 2,3-diF (1.01) > 2,3-diCl (0.74) > 3,4-diF (0.52) > 2,6-diF (0.45) > 3,5-diF (0.44) > 2,5-diF (0.33). Relatively high Tg of the copolymers in comparison with that of polystyrene indicates a decrease in chain mobility of the copolymer due to the high dipolar character of the trisubstituted ethylene monomer unit. Decomposition of the copolymers in nitrogen occurred in two steps, first in the 250–500°C range with residue (2.6–5.0 wt%), which then decomposed in the 500–800°C range.  相似文献   

15.
Novel copolymers of trisubstituted ethylene monomers, ring-substituted 2-phenyl-1,1-dicyanoethylenes, RC6H3CH?C(CN)2 (where R is 2,3-(CH3O)2, 2,4-(CH3O)2, 2,5-(CH3O)2, 2,6-(CH3O)2, 3,4-(CH3O)2, and 3,5-(CH3O)2 and 4-fluorostyrene were prepared at equimolar monomer feed composition by solution copolymerization in the presence of a radical initiator (ABCN) at 70°C. The composition of the copolymers was calculated from nitrogen analysis, and the structures were analyzed by IR, 1H and 13C-NMR. The order of relative reactivity (1/r 1) for the monomers is 2,6-(CH3O)2(2.8) > 2,5-(CH3O)2(2.5) > 2,3-(CH3O)2 (2.1) > 3,5-(CH3O)2 (1.8) > 3,4-(CH3O)2 (0.9) > 2,4-(CH3O)2 (0.7). High Tg of the copolymers, in comparison with that of poly(4-fluorostyrene) indicates a substantial decrease in chain mobility of the copolymer due to the high dipolar character of the trisubstituted ethylene monomer unit. Decomposition of the copolymers in nitrogen occurred in two steps, first in the 250–400°C range with residue, which then decomposition in 400–800°C range.  相似文献   

16.
Electrophilic trisubstituted ethylenes, ring-disubstituted methyl 2-cyano-3-phenyl-2-propenoates, RPhCH?C(CN)CO2CH3, where R is 2,5-dichloro, 3,5-dichloro, 2,3-difluoro, 3-chloro-2-fluoro, 3-chloro-4-fluoro, 4-chloro-3-fluoro, 2-chloro-5-nitro, and 2-chloro-6-nitro were prepared and copolymerized with styrene. The monomers were synthesized by the piperidine catalyzed Knoevenagel condensation of ring-disubstituted benzaldehydes and methyl cyanoacetate, and characterized by CHN analysis, IR, 1H and 13C-NMR. All the ethylenes were copolymerized with styrene (M1) in solution with radical initiation (ABCN) at 70°C. The compositions of the copolymers were calculated from nitrogen analysis and the structures were analyzed by IR, 1H and 13C-NMR. The order of relative reactivity (1/r1) for the monomers is 4-Cl-3-F (4.87) > 2,3-F2 (4.49) > 3-Cl-4-F (3.50) > 3-Cl-2-F (2.96) > 2-Cl-5-NO2 (2.02) > 2,5-Cl2 (1.54) > 2-Cl-6-NO2 (1.00) > 3,5-Cl2 (0.41). Relatively high Tg of the copolymers in comparison with that of polystyrene indicates a decrease in chain mobility of the copolymer due to the high dipolar character of the trisubstituted ethylene monomer unit. Decomposition of the copolymers in nitrogen occurred in two steps, first in the 200–500ºC range with residue (1.5–34.5% wt), which then decomposed in the 500-800ºC range.  相似文献   

17.
Electrophilic trisubstituted ethylenes, halogen ring-substituted methyl 2-cyano-3-phenyl-2-propenoates, RPhCH=C(CN)CO2CH3 (where R is 3-Br-4-CH3O, 5-Br-2-CH3O, 2-F-5-CH3, 2-F-6-CH3, 4-F-3-CH3, 4-F-3-PhO, 2-F-5-I, 2-F-6-I, 2-F3C, 4-F3C) were prepared and copolymerized with styrene. The monomers were synthesized by the piperidine catalyzed Knoevenagel condensation of ring-substituted benzaldehydes and methyl cyanoacetate, and characterized by CHN analysis, IR, 1H and 13C-NMR. All the ethylenes were copolymerized with styrene (M1) in solution with radical initiation (ABCN) at 70°C. The compositions of the copolymers were calculated from nitrogen analysis and the structures were analyzed by IR, 1H and 13C-NMR. The order of relative reactivity (1/r 1) for the monomers is 2-F-5-CH3 (6.4) > 4-F-3-PhO (5.6) > 4-F3C (4.8) > 3-Br-4-CH3O (3.7) > 2-F-5-I (3.6) > 2-F3C (2.2) > 2-F-6-I (2.1) > 5-Br-2-CH3O (1.9) > 4-F-3-CH3 (1.8) > 2-F-6-CH3 (1.2). Relatively high T g of the copolymers in comparison with that of polystyrene indicates a decrease in chain mobility of the copolymer due to the high dipolar character of the trisubstituted ethylene monomer unit. Decomposition of the copolymers in nitrogen occurred in two steps, first in the 200-500°C range with residue (2–21% wt), which then decomposed in the 500–800°C range.  相似文献   

18.
Electrophilic trisubstituted ethylenes, phenoxy ring-substituted methyl 2-cyano-3-phenyl-2-propenoates, RPhCH=C(CN)CO2CH3, where R is 4-(4-BrC6H5O), 2-(4-ClC6H5O), 3-(4-ClC6H5O), 4-(3-ClC6H5O), 4-(4-ClC6H5O), 4-(4-FC6H5O), 2-(3-CH3OC6H5O), 2-(4-CH3OC6H5O), 3-(4-CH3OC6H5O), 4-(4-CH3OC6H5O), 3-(4-CH3C6H5O) were prepared and copolymerized with styrene. The monomers were synthesized by the piperidine catalyzed Knoevenagel condensation of phenoxy ring-substituted benzaldehydes and methyl cyanoacetate, and characterized by CHN analysis, IR, 1H and 13C-NMR. All the ethylenes were copolymerized with styrene (M1) in solution with radical initiation (ABCN) at 70°C. The compositions of the copolymers were calculated from nitrogen analysis and the structures were analyzed by IR, 1H and 13C-NMR. The order of relative reactivity (1/r1) for the monomers is 4-(4-CH3OC6H5O) (6.07) > 3-(4-ClC6H5O) (3.38) > 3-(4-CH3OC6H5O) (2.78) > 4-(3-ClC6H5O) (2.77) > 2-(4-ClC6H5O) (2.29) > 3-(4-CH3C6H5O) (1.98) > 4-(4-FC6H5O) (1.92) > 4-(4-ClC6H5O) (1.89) > 2-(3-CH3OC6H5O) (1.39) > 2-(4-CH3OC6H5O) (0.90) > 4-(4-BrC6H5O) (0.77). Relatively high Tg of the copolymers in comparison with that of polystyrene indicates a decrease in chain mobility of the copolymer due to the high dipolar character of the trisubstituted ethylene monomer unit. Decomposition of the copolymers in nitrogen occurred in two steps, first in the 200-500°C range with residue (2.5-8.0% wt), which then decomposed in the 500-800°C range.  相似文献   

19.
Electrophilic trisubstituted ethylenes, ring-trisubstituted methyl 2-cyano-3-phenyl-2-propenoates, RPhCH = C(CN)CO2CH3 (where R is 2,4,6-trimethyl, 3,5-dimethoxy-4-hydroxy, 3,5-dimethyl-4-hydoxy, 3,4,5-trimethoxy, 2-bromo-3-hydroxy-4-methoxy, 5-bromo-2,3-dimethoxy, 5-bromo-2,4-dimethoxy, 6-bromo-3,4-dimethoxy were prepared and copolymerized with styrene. The monomers were synthesized by the piperidine catalyzed Knoevenagel condensation of ring-trisubstituted benzaldehydes and methyl cyanoacetate, and characterized by CHN analysis, IR, 1H and 13C-NMR. All the ethylenes were copolymerized with styrene (M1) in solution with radical initiation (ABCN) at 70°C. The compositions of the copolymers were calculated from nitrogen analysis and the structures were analyzed by IR, 1H and 13C-NMR. The order of relative reactivity (1/r1) for the monomers is 5-bromo-2,3-dimethoxy (2.69) > 3,4,5-trimethoxy (1.86) > 6-bromo-3,4-dimethoxy (0.84) > 5-bromo-2,4-dimethoxy (0.39) > 4-hydoxy-3,5-dimethyl (0.31) = 2-bromo-3-hydroxy-4-methoxy (0.31) > 3,5-dimethoxy-4-hydroxy (0.24) > 2,4,6-trimethyl (0.22). Relatively high Tg of the copolymers in comparison with that of polystyrene indicates a decrease in chain mobility of the copolymer due to the high dipolar character of the trisubstituted ethylene monomer unit. Decomposition of the copolymers in nitrogen occurred in two steps, first in the 200–500ºC range with residue (1–6% wt), which then decomposed in the 500–800ºC range.  相似文献   

20.
Novel trisubstituted ethylenes, oxy ring-substituted butyl 2-cyano-3-phenyl-2-propenoates, RPhCH=C(CN)CO2C4H9 (where R is 2-methoxy, 3-methoxy, 4-methoxy, 2-ethoxy, 3-ethoxy, 4-ethoxy, 4-propoxy, 4-butoxy, 4-hexyloxy, 3-phenoxy) were prepared and copolymerized with styrene. The monomers were synthesized by the piperidine catalyzed Knoevenagel condensation of oxy ring-substituted benzaldehydes and butyl cyanoacetate and characterized by CHN elemental analysis, IR, 1H- and 13C-NMR. All the ethylenes were copolymerized with styrene (M1) in solution with radical initiation (ABCN) at 70°C. The composition of the copolymers was calculated from nitrogen analysis, and the structures were analyzed by IR, 1H and 13C-NMR, GPC, DSC, and TGA. The order of relative reactivity (1/r1) for the monomers is 4-methoxy (6.56) > 3-methoxy (2.97) > 2-methoxy (2.72) > 4-butoxy (2.20) > 3-ethoxy (2.18) > 4-propoxy (2.15) > 4-hexyloxy (1.78) > 4-ethoxy (1.66) > 2-ethoxy (1.48) > 3-phenoxy (1.29). Decomposition of the copolymers in nitrogen occurred in two steps, first in the 200-500°C range with residue (0.8–3.6% wt.), which then decomposed in the 500–800°C range.  相似文献   

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