The microstructures of the hybrid core-shell latex synthesized by emulsion copolymerization of 3-trimethoxysilyl propyl methacrylate（MPS） and styrene were investigated.The polymers obtained under different operating...The microstructures of the hybrid core-shell latex synthesized by emulsion copolymerization of 3-trimethoxysilyl propyl methacrylate（MPS） and styrene were investigated.The polymers obtained under different operating conditions were characterized by（）29Si solid state NMR,FTIR,DSC and elemental analysis.It was found that under a neutral condition all of the MPS monomers were copolymerized into the polymer chain,small part of SiOR groups were hydrolyzed into SiOH groups and crosslinked by hydrogen bonds,the content of crosslinking is increased by MPS addition amount.Under basic condition,part of MPS were hydrolyzed and condensed into oligomers firstly,then these resultants were grafted into the polymer chain as pendent chain by both free radical polymerization and hydrolysis-condensation reaction.And under acidic condition,MPS in the system was easily hydrolyized and acted as crosslinker so that the emulsion became gels rapidly.展开更多
以甲基丙烯酸甲酯(MMA)和3-环己烯-1-甲醇为原料,采用酯交换法合成了甲基丙烯酸-3-环己烯基甲酯,考察了催化剂种类与用量、反应时间以及反应物配比等因素对反应结果的影响。得到的较佳反应条件为采用有机锡类催化剂,m(有机锡)∶m(3-环己...以甲基丙烯酸甲酯(MMA)和3-环己烯-1-甲醇为原料,采用酯交换法合成了甲基丙烯酸-3-环己烯基甲酯,考察了催化剂种类与用量、反应时间以及反应物配比等因素对反应结果的影响。得到的较佳反应条件为采用有机锡类催化剂,m(有机锡)∶m(3-环己烯-1-甲醇)=0.06、反应时间5h、n(MMA)∶n(3-环己烯-1-甲醇)=3∶1。在此条件下,3-环己烯-1-甲醇的转化率达97%以上,产品收率大于94%。并采用IR和1 H NMR技术对产品的结构进行了表征。展开更多
采用有机合成方法制备反应型紫外线吸收剂2-羟基-4-(3-甲基丙烯酸酯基-2-羟基丙氧基)二苯甲酮(BPMA)。利用制得的BPMA,以聚偏氟乙烯(PVDF)粉体为基材,进行预辐照接枝反应,制得PVDF-g-BPMA。预辐照实验中PVDF的辐照剂量为15 k Gy,在流变...采用有机合成方法制备反应型紫外线吸收剂2-羟基-4-(3-甲基丙烯酸酯基-2-羟基丙氧基)二苯甲酮(BPMA)。利用制得的BPMA,以聚偏氟乙烯(PVDF)粉体为基材,进行预辐照接枝反应,制得PVDF-g-BPMA。预辐照实验中PVDF的辐照剂量为15 k Gy,在流变仪中的熔融接枝反应温度为190℃,反应时间为6 min,转速为50 r/min。通过核磁共振氢谱、傅里叶变换红外光谱、差示扫描量热、广角X射线衍射以及紫外–可见光谱等对PVDFg-BPMA进行结构表征与紫外线吸收性能测试。结果表明,BPMA成功接枝到PVDF上,接枝率达7.04%。接枝后PVDF的结晶度降低,但晶型未发生改变。相比于未接枝的PVDF,PVDF-g-BPMA薄膜在280~340 nm波长内的紫外光透过率降至0.27%以下,表现出优异的紫外线吸收性能,同时与PVDF/BPMA复合膜相比,其经乙醇抽提48 h后的紫外线吸收性能没有明显变化,表明PVDF预辐照接枝BPMA有效防止了紫外线吸收剂在PVDF内的外迁移。展开更多
文摘The microstructures of the hybrid core-shell latex synthesized by emulsion copolymerization of 3-trimethoxysilyl propyl methacrylate（MPS） and styrene were investigated.The polymers obtained under different operating conditions were characterized by（）29Si solid state NMR,FTIR,DSC and elemental analysis.It was found that under a neutral condition all of the MPS monomers were copolymerized into the polymer chain,small part of SiOR groups were hydrolyzed into SiOH groups and crosslinked by hydrogen bonds,the content of crosslinking is increased by MPS addition amount.Under basic condition,part of MPS were hydrolyzed and condensed into oligomers firstly,then these resultants were grafted into the polymer chain as pendent chain by both free radical polymerization and hydrolysis-condensation reaction.And under acidic condition,MPS in the system was easily hydrolyized and acted as crosslinker so that the emulsion became gels rapidly.
文摘以甲基丙烯酸甲酯(MMA)和3-环己烯-1-甲醇为原料,采用酯交换法合成了甲基丙烯酸-3-环己烯基甲酯,考察了催化剂种类与用量、反应时间以及反应物配比等因素对反应结果的影响。得到的较佳反应条件为采用有机锡类催化剂,m(有机锡)∶m(3-环己烯-1-甲醇)=0.06、反应时间5h、n(MMA)∶n(3-环己烯-1-甲醇)=3∶1。在此条件下,3-环己烯-1-甲醇的转化率达97%以上,产品收率大于94%。并采用IR和1 H NMR技术对产品的结构进行了表征。
