Study Of Biodegradable Liquid Crystalline Polyester

Because the pollution of the environment is more and more serious, the studies and development of biodegradation materials are put more and more eyes on. In this paper, a mesogenic monomer 4,4-dimethyl (1,4-bendizoyloxy) dibenzoate is designed and synthesized. By melted state transesterification, a series of liquid crystalline copolyesters are synthesized and identified by introducing the mesogenic monomer into the chain of polybutylene succinate (PBS) in order to modify PBS.The effects of factors on mesogenic monomer's preparation are studied. The reaction is radiative and the catalyst (triethylamine) is important to it. Melted state transesterification is adopted by mesogenic monomer, 1, 4-BDO and BDS. The chain extension of the polyester is accomplished by using TDI or HDI. In this thesis, systematic studies are made on polycondensation and chain extension. The favorable conditions are as follows: the transesterification temperature is 140~160°C,the after- polycondensation temperature is 220—230°C,the mole ratio of hydroxyl/methylic ester is 2.5 to 1. Chain extension kinetics is investigated.In order to get more molecular weight, method is changed. TOBB and PBS are synthesized respectively. Then chain extender is throwed into flask extending. The measurement of heat properties and the mechanics properties indicates that the properties of modified polymer increases than PBS. The biodegradation study of the copolyesters is carried out in solution and soil burial. The synthesized liquid crystalline copolyesters display good biodegradability.