摘要
概述了光引发体系、光照强度、单体平均官能度、液晶含量、反应温度、助剂等对乙烯基单体/液晶混合物光聚合动力学及光固化流变行为的影响.在染料和胺组成的二元Ⅱ型(夺氢型)光引发体系中,引入适当的第三组分能显著提高反应速率和转化率;增加光照强度和升高温度也能显著提高反应速率和转化率.随着单体平均官能度的增加,体系的反应速率和转化率呈现先增加后降低的趋势.对于Ⅰ型(裂解型)光引发剂,液晶含量增加,单体反应速率降低,但转化率基本不变;但对于Ⅱ型光引发剂,液晶含量增加能大幅提高单体反应速率和转化率.加入使体系黏度降低的助剂也能提高体系的反应速率和转化率.在体系相同、温度固定的条件下,反应速率越高,凝胶化时间越短;相同体系,温度升高,凝胶化时间提前;相同温度下,单体官能度愈高,体系凝胶时间亦愈短.
The effects of photoinitiators,light intensity,average functionality of mixed monomers,liquid crystal content,temperature and additives on the photopolymerization kinetics and photo-rheological behaviors of vinyl-monomer/liquid crystal mixtures are reviewed.The rate of polymerization Rp and monomer conversion α greatly increase when an appropriate third component is added into the binary dye/amine type Ⅱ （H-abstraction type） photoinitiator system,and also largely increase when light intensity or temperature rises.Rp and α first ascend and then descend with increasing the average functionality of mixed monomers.With an increase of liquid crystal content,Rp diminishes while there is no evident variation of α for the type Ⅰ （cleavage type） photoinitiator; on the contrary,both Rp and α significantly increase for the type Ⅱ photoinitiator in that condition.Additives that can lower the viscosity of monomer/liquid crystal mixtures also increase Rp and α.Generally,higher Rp causes shorter gelation time for an identical system at a given temperature,and gelation takes place earlier when temperature increases for an identical system or the average functionality of mixed monomers rises at a fixed temperature.
出处
《高分子学报》
SCIE
CAS
CSCD
北大核心
2012年第11期1218-1224,共7页
Acta Polymerica Sinica
基金
国家自然科学基金杰出青年基金(基金号50825301)资助项目
关键词
全息聚合物分散液晶
光聚合动力学
光固化流变行为
相分离
凝胶化
Holographic polymer dispersed liquid crystals, Photopolymerization kinetics, Photo-rheology,Phase separation, Gelation
