反應摻合聚碳酸酯高分子參與共聚酯高分子

Abstract

聚碳酸酯 ( Poly(bisphenol-A carbonate)) PC 和在實驗室合成之共聚 酯高分子(Poly(p-oxybenzoate-co-ethylene terephthalate)；40: 60) P46 的摻合是在 Branbender Mixer 中進行。在 240℃，250℃和 260℃ 三種溫度下摻合，Branbender Mixer 的轉速為 50 rpm來分析PC/ P46 摻 合物可混合性(miscible)的研究。以熱差分析儀 (differential scanning calorimetry；DSC)，測量摻合物因 P46 含量和摻合溫度、時 間所造成的改變，結果發現當摻合物中 P46 的含量和摻合溫度愈高則摻 合物的玻璃轉化點下降的愈低。摻合物的酯交換行為則以紅外線光譜 (Fouier transformed infra-red;FTIR)和13C核磁共振譜(Nuclear magnectic resonance; NMR) 探討之，發現在 240℃ 時雖然以 FTIR 測 量結果顯示有酯交換的情形產生。但 NMR 卻無法偵測到摻合物中酯基的 化學化移(chemical shift)，但在260℃，長時間下，此兩種儀器則可同 時偵測到有酯交換反應的產生。以掃描式電子顯微鏡 (scanning electron microscope；SEM) 觀察聚碳酸酯高分子和共聚酯高分子的相容 性，可以發現在低溫短時間摻合皆發現共聚酯高分子形成液滴狀分佈在聚 碳酸酯高分子相中形成相分離的現象，在較高溫且長時間下則液滴狀形態 消失，可能由於酯交換反應增加之故，而摻合物在摻合時所顯示的力矩值 和以平行板流變儀(rheometer)所測得切變速率對切變黏度的作圖，都說 明了此一共聚酯高分子，能夠大幅度降低聚碳酸酯高分子的黏度。 Blends of Poly(bisphenol-A carbonate) PC and in-house synthesizedPoly(p-oxybenzoate-co-ethylene terephthalate) (40:60) P46 were melt- mixed in a Branbender Mixer at three temperatures, 240℃, 250℃, 260℃. The speed of the mixing blades was 50 rpm. The miscibility of the blends was investigated with differential scanning calorimetry (DSC).The kinetics of transesterification of the blends of PC and P46 was studied with Fourier transformed infrared spectrometry (FTIR) and Nuclear magnetic resonance (NMR). It was found that the extent of the transesterification increased with the amount of P46 in PC , the temperature and the reaction time. Scanning electron microscope (SEM)studies revealed that the copolyester formed droplets in PC matrix at low temperatures and short reaction time , but disappeared at higher temperature and longer reaction time. The viscosity of the blends studies with a stress rheometer (CSL-500) . The adding of the copolyester to PC reduced the viscosity of the host polymer.