Study on Synthesis of Tailor-Made Block Copolymers Having Side Chains of Liquid Crystal and its Application to Recording Materials.

点击翻译按钮获取中文摘要

To obtain a molecular memory, one needs not only the conditions, easy isomerization of dye to metastable state in recording, suppression of thermal backward isomerization in keeping, and easy backward isomerization in deleting, but also high mechanical strength. For the purpose, it is desirable to use bifunctional die as cross-linker onto block copolymer having a component of high glass transition temperature. It was found that N, N-dimethyl-4-vinylphenethylamine (PTA) is an appropriate monomer for the present purpose. Preparation and purification of PTA monomer is not so difficult. PTA can be polymerized anionically in THF at 195K with cumyl potassium or cumyl cesium as an initiator. The obtained poly (PTA) has a narrow molecular weight distribution. A well defined diblock copolymer, poly (PTA-b-styrene) can be obtained, if PTA is polymerized prior to styrene. The glass transition temperature of poly (PTA) is 315K. A quarternization of the block copolymer with p, p'-bis (chloromethyl) azo-benzene (CAB) can be easily carried out in a membrane form. An isomerization of such incorporated CAB from trans to cis form can be made by irradiation of UV light. Thermal backward isomerization is negligible at room temperature but easy at a temperature higher than the glass transition temperature of poly (PTA). These facts allow us to make a molecular memory by the use of poly (PTA) and CAB.