| Liquid crystal elastomer(LCE)is a kind of high elastic body with ordered orientation formed by crosslinking mesomorphic units.Its characteristics include the self-organization of the liquid crystal system and the elastic flexibility of the polymer network.Among them,photothermotropic liquid crystal elastomers have attracted the focus of scientific research and exploration of many scientists because of their significant advantages such as instantaneity,remote controllability,and environmental protection.The important obstacle to the practical industrial application of LCE material is its moderate robustness and photothermal conversion efficiency as actuator material.At present,most liquid crystal elastomer composites use biomass fiber networks as a reinforcement phase by adding nano materials to the polymer matrix.Therefore,in this paper,the main chain liquid crystal elastomer composites were prepared by an ultrasonic chemical method by selecting the appropriate duck down fiber network(0.7% wt)as the flexible reinforcing phase and adding graphene powder(0.5% wt).The main research contents are as follows:(1)The main chain liquid crystal monomers 4-(but-3-en-1-yloxy)phenyl 4-(but-3-en-1-yloxy)benzoate(LC44)and 4-(hex-5-en-1-yloxy)phenyl 4-(hex-5-en-1-yloxy)benzoate(LC66)were synthesized and prepared.The rapid reaction of precursor molecules was stimulated by high-frequency ultrasound to obtain the main chain liquid crystal elastomer film material with stable performance.The preparation process of main chain liquid crystal elastomer was optimized and the production efficiency was improved.(2)LCE / FB(fibers incorporated LCE composite)was prepared by ultrasonic chemical method.Under the stimulation of a certain heat source,the thermal shrinkage deformation of LCE / FB composite can reach about 53%,and the thermal actuation stress and modulus are increased.(3)Biomass down fiber liquid crystal elastomer nanocomposites containing graphene were prepared by ultrasonic chemical method.Under the irradiation of pseudo sunlight area actuating light source,the photoinduced deformation of biomass down fiber liquid crystal elastomer nanocomposites containing graphene can reach more than 55%,and the tensile strength and fatigue damage resistance is enhanced,which has good fatigue damage resistance.This material has potential applications in soft actuators,the chemical industry,and other fields. |
PDF Full Text Request