摘要
采用光-流变学方法研究了丙烯酸酯/液晶复合体系的光聚合凝胶时间及体积收缩率,并与密度法测量的体积收缩率进行了对比.结果表明,该复合体系的凝胶时间小于10 s,光-流变学方法可以在线测量丙烯酸酯单体/液晶复合体系的光聚合体积收缩.以2种不同结构的多面体齐聚倍半硅氧烷(POSS)掺杂丙烯酸酯/液晶复合体系,八甲基丙烯酰氧基倍半硅氧烷(MA-POSS)使丙烯酸酯/液晶复合体系的双键转化率略有降低,掺杂10 wt%MA-POSS使体系的光聚合体积收缩率仅降低了12%;而甲基丙烯酰氧基七异丁基倍半硅氧烷(MI-POSS)对体系双键转化率的影响较小,显著降低了体系的光聚合体积收缩,掺杂10 wt%MI-POSS使体系的光聚合体积收缩率降低29%.
A photo-rheometer with a UV-cure monitoring accessory was used to measure the gelation time and volume shrinkage of acrylate /liquid crystal syrups during photopolymerization,and the volume shrinkage data were compared with those obtained from density approaches. The experimental results show that gelation times of these syrups are shorter than 10 s and the volume shrinkages are alomost the same via the different test approaches,which implies the photo-rheology（ P-Rheology） technique is an accurate and easy method to measure online photopolymerization volume shrinkage of acrylate /liquid crystal systems. Two types of polyhedral oligomeric silsesquioxane（ POSS）,methacrylisobutyl polyhedral oligomeric silsesquioxane（ MIPOSS） and methacryl polyhedral oligomeric silsesquioxane（MA-POSS）,were added to acrylate /liquid crystal syrups in order to reduce their volume shrinkage during photopolymerization. P-Rheology and photo-differential scanning calorimetry（ P-DSC） were used to investigate the effects of POSS content and type on volume shrinkage and double-bond conversion of acrylate /liquid crystal syrups,respectively. The results indicate that MA-POSS slightly decreases the double-bond conversion while does not bring obvious effect on the volume shrinkage. Adding 10 wt% MA-POSS only declines the photopolymerizion volume shrinkage by 12%.However,MI-POSS does not change the double bond conversion while can reduce markedly the volume shrinkage. The photopolymerizion volume shrinkage of acrylate /liquid crystal syrups is decreased by 29% with adding 10 wt% MI-POSS.
出处
《高分子学报》
SCIE
CAS
CSCD
北大核心
2014年第10期1408-1412,共5页
Acta Polymerica Sinica
基金
国家自然科学基金(基金号51210004
51273073)资助项目
关键词
丙烯酸酯/液晶复合体系
多面体齐聚倍半硅氧烷
体积收缩
光聚合
光-流变学
Acrylate /liquid crystal syrups
Polyhedral oligomeric silsesquioxane（POSS）
Volume shrinkage
Photopolymerization
Photo-rheology
