Poly(ether-b-ester) Thermoplastic Elastomers : Synthesis and Properties = Poly(ether-b-ester) Thermoplastic Elastomers의 합성 및 물성 연구

국문 초록 (Abstract)

디메틸 테레프탈레이트 (DMT), 1,4-부탄디올 (1,4-BD) 그리고 분자량이 2000인 폴리테트라 메틸렌에테르 글리콜 (PTMG)로 부터 폴리에스터계 열가소성 탄성체 (TPEE)를 합성할 수 있었다. 고온에서의 열적 안정성및 기계적 물성을 증대시킬 목적으로 열처리를 하였으며, 이에 따라 결정성 hard segmen의 보다 규칙적인 배열로 인한 향상된 물성을 확인 할 수 있었다 본 실험에서 합성된 공중합체는 soft segment의 함량이 증가함에 따라 융점및 결정화도가 감소함을 보여 주었다. 기계적 물성의 경우, soft segment의 함량이 35%인 공중합체가 soft segment와 hard segment간 최적의 물리적 가교점 형성으로 인하여 가장 우수함이 관찰 되었다.

다국어 초록 (Multilingual Abstract)

The poly(ether-b-ester) thermoplastic elastomers (TPEEs) were synthesized by melt polymerization using dimethyl terephthalate (DMT), 1,4-butanediol (1,4-BD) and poly (tetramethylene ether) glycol (PTMG) in the molecular weight of 2000 (g/㏖). The copolymers were prepared with a constant PBT mass ratio of 100; the content of PTMG was changed.
To improve thermal stability at elevated temperatures and mechanical properties, the final copolymers were annealed. The chemical structure and thermal properties of them were examined by utilizing FT-IR and DSC. For a better understanding of the structure and property relationships, SEM and a three-point loading system (UTM) were used. The rheological characteristics of them involving the changes of viscosity with the increasing shear rate were also studied.
From this experiment, it was shown that as the proportion of soft segment increases melting temperature and degree of crystallinity of TPEEs decrease constantly and the lamella structure was found to be less fine in shape. Meanwhile, in case of flexural strength and flexural elastic modulus, 35-PTMG^(2000) indicates the highest values. As the shear rate increases thixotropy (shear thinning), one of the non-newtonian flows, is found. The results of melt flow properties seem tc be similar to those of strength and elastic modulus in flexure, and 35-PTMG^(2000) shows the viscosity higher than others.
A11 of the properties of the copolymers synthesized in this work were found to be improved by thermal treatment.