熱向型段式聚(對羧苯甲酸酯-對-二苯甲酸乙烯共聚酯)之合成

Abstract

利用聚對苯二甲酸乙二醇酯（polyethylene terephthalate，PET）、醋 酸基苯甲酸（4-acetoxybenzoic acid ，ABA）與聚對羧基苯甲酸（poly (4-hydroxybenzoate)，PHBA）的寡聚合體合成段式共聚酯，並以DSC、 TGA、WAXS與POM來分析段式共聚酯。PHBA的固態 CP/MAS 13C 核磁共振光 譜顯示低聚合度的PHBA是由單一種修正的斜方晶系所構成的；高聚合度的 PHBA則是由兩種不同修正的斜方晶系所構成的。共聚酯DSC曲線中PET的結 晶溫度Peak寬度隨著雜式到段式有減小的趨勢；轉換點焓則隨著雜式到段 式有增加的趨勢。共聚酯WAXS曲線中在2θ=19.5度隨著雜式到段式有一新 的peak長出。利用POM分析，第一次有證據顯示段式共聚酯能在如此低的 PHB（20 mol %）組成下，表現出有液晶相的存在。段式共聚酯在360℃時 有強烈的對酯交換反應發生，而形成雜式共聚酯。 A series of liquid crystalline block copolyesters synthesized from poly(ethylene terephalate) (PET) , 4-acetoxybenzoic acid (ABA) and poly(4-hydroxybenzoate) (PHBA) oligomer have been examined by DSC, TGA, WAXS and POM. Solid-State CP/MAS 13C NMR spectra of PHBA have shown that the low degree of polymerization (DP) PHBA consists of one orthorhombic crystal modification and the high DP PHBA consists of two different orthorhombic crystal modifications. The sharpness of crystalline temperature (Tc) peak increases with the blockness of copolyesters. The enthalpy difference during the high transition temperature (ΔＨm) also increases with the blockness of copolyester. The crystal peak at 2θ=19.5°grows with the blockness of copolyesters. POM results revealed that for the fist time block copolyesters containing only 20 mol % PHB exhibited liquid crystalline phases. Severe transesterfication in these block copolyesters took place at 360℃to convert to random coployesters.