摘要
为了研究甲壳效应对液晶弹性体热致形变和力学性能的影响。通过多步反应设计并合成了具有降冰片烯主链结构的甲壳型液晶弹性体。利用1H NMR表征化合物结构,采用热台偏光显微镜和动态力学热分析仪研究弹性体的液晶行为、热致形变性质和力学性能。将甲壳型液晶聚合物与双官能度的二苯甲酮交联剂混合,熔融拉丝,得到取向单一的纤维,在液晶相温度下紫外光照引发交联反应,制备出甲壳型液晶弹性体。实验结果表明甲壳型液晶弹性体纤维样品在常温下具有双折射性质,表现为沿纤维长轴方向的单畴取向。在外力作用下,纤维样品具有可逆的热致形变性质,最大形变率达到62%。力学性能测试显示,该纤维样品在玻璃相态下具有较高的杨氏模量,而在液晶相态下则表现为较大的应变量。
The influence of the"jacket effects"on the thermo-actuation and mechanical properties of MJLCE was investigated.A new type of mesogen-jacketed liquid crystalline elastomer(MJLCE)which bears a novel polynorbornene backbone was designed and successfully synthesized via multi-step reactions.The chemical structures of the monomer and polymer were confirmed by 1H NMR.The mesomorphic behaviors,thermo-actuation and mechanical properties of the MJLCE were investigated by thermal polarizing microscope and dynamic mechanical thermal analysis.MJLCE is prepared by mixing the MJLCP(mesogenjacketed liquid crystalline polymer)with bifunctional benzophenone cross-linkers,melting the mixture,then pulling fibers to achieve a fine alignment,and crosslinking under UV illumination.The results showed that the hand-made MJLCE fibers display birefringent under normal temperature which corresponded to a smectic phase with a fine alignment of the molecular director along the fiber axis.It was also found that the contraction of the fibers sample during the phase transition was reversible under an external force.The fibers showed high Young's modulus under the glass phase.When the temperature rose to the liquid crystalline phase,the Young's modulus significantly decreased,and the fibers exhibited large strained.
作者
张飞
张宇
李志宏
岳晓煜
张亚杰
ZHANG Fei ZHANG Yu LI Zhihong YUE Xiaoyu ZHANG Yajie(Department of Forensic Science Technology of Jiangsu Police Institute,Nanjing 210031 ,China)
出处
《南昌大学学报(理科版)》
CAS
北大核心
2016年第6期584-591,共8页
Journal of Nanchang University(Natural Science)
基金
2015年江苏省高等学校大学生实践创新训练计划一般项目(201510329060X)
江苏警官学院科研项目(2014SJYZQ03)
江苏警官学院"物证分析技术"科研创新团队(2015SJYTZ03)
江苏省高等学校重点学科建设专项资金(20160838)
江苏省高校优势学科建设工程资助项目(PAPD)(2011年)
关键词
甲壳型液晶高分子
弹性体
聚降冰片烯
Mesogen-jacketed liquid crystalline polymers
Elastomers
Polynorbornene