摘要
采用原位乙酰化法 ,合成了对羟基苯甲酸 (PHB)摩尔分数不同的PBT/PHB共聚酯 ,研究了其组成与相转变和液晶性之间的关系。结果表明 ,采用PHB的原位乙酰法合成的PBT/PHB共聚酯 ,当PHB刚性基元的摩尔分数为为 2 0 %～ 80 %时 ,PBT/PHB共聚酯为向列型热致性液晶 ,并存在明显的双玻璃化现象 ;当PHB的摩尔分数达到 60 %后 ,共聚酯表现出两个熔点。这种多重相转变与PBT/PHB共聚酯中存在不同程度的富PBT相和富PHB相有关。采用PHB的原位乙酰化法代替乙酰氧基苯甲酸的酯交换法 ,一定程度上抑制了PHB嵌段链的形成。
Poly(butylene terephthalate)/p-hydroxybenzoic acid copolyesters (PBT/PHB) with different mole fractions of PHB were synthesized from PBT and PHB by in-situ acetylation. The relationships between their phase transition and liquid crystallinity and the composition were investigated. The results showed that the PBT/PHB copolyesters synthesized by in-situ acetylation showed nematic liquid crystalline behavior and two glass transition temperatures when the mole fraction of PHB was 20% ～ 80 %; when the mole fraction of PHB was up to 60 %, the PBT/PHB copolyesters had two melting temperatures, which were related to PBT-rich phase and PHB-rich phase in the copolyester. Compared with the ester interchange of p-acetoxybenzoic acid and PBT, the in-situ acetylation of PHB was useful to restrain from the forming of long PHB blocking chains.
出处
《塑料工业》
CAS
CSCD
北大核心
2004年第1期4-6,25,共4页
China Plastics Industry
基金
国家自然科学基金项目 (5 0 0 0 3 0 0 5和 10 172 0 3 7)资助
