A new family of terephthalate-based copolyesters has been found to exhibit high impact resistance combined with good thermal properties, ultraviolet stability, optical clarity, and low color. These engineering thermoplastic compositions were prepared using conformationally rigid cis/trans-2,2,4,4-tetramethyl-1,3-cyclobutanediol [CBDO] and flexible C₂−C₄ aliphatic glycols. The copolymers were amorphous when the CBDO (∼50/50 cis/trans) content was about 40 to 90 mol % of total diol. Glass transition temperatures were 80−168 °C, depending on the proportion of rigid CBDO units. Impact resistance was inversely proportional to CBDO content, and notched Izod values as high as 1000 J/m were obtained. Both high T_g (>100 °C) and high impact (250−750 J/m) can be realized simultaneously for compositions containing about 50−80 mol % CBDO. Accelerated weathering indicated good inherent resistance of 1,3-propanediol/CBDO copolyterephthalate to yellowing under ultraviolet radiation. Dibutyltin oxide was more effective for transesterification of CBDO with dimethyl terephthalate than other typical catalysts. Better color and higher molecular weights were obtained with this catalyst when the flexible diol was 1,3-propanediol or 1,4-butanediol rather than ethylene glycol.

中文翻译：

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刚性2,2,4,4-四甲基-1,3-环丁二醇与柔性二醇的高抗冲，无定形对苯二甲酸共聚酯

已经发现新的基于对苯二甲酸酯的共聚酯家族显示出高的耐冲击性，同时具有良好的热性能，紫外线稳定性，光学清晰度和浅色。这些工程热塑性组合物是使用构象刚性的顺式/反式-2,2,4,4-四甲基-1,3-环丁二醇[CBDO]和柔性的C ₂ -C ₄脂族二醇制备的。当CBDO（〜50/50顺/反含量为总二醇的约40至90mol％。玻璃化转变温度为80-168°C，具体取决于刚性CBDO单元的比例。耐冲击性与CBDO含量成反比，缺口Izod值高达1000 J / m。均高T _g对于含约50-80 mol％CBDO的组合物，可以同时实现（> 100°C）和高冲击（250-750 J / m）。加速的风化表明1，3-丙二醇/ CBDO共聚对苯二甲酸乙二酯在紫外线辐射下具有良好的固有耐黄变性。与其他典型催化剂相比，二丁基氧化锡对CBDO与对苯二甲酸二甲酯的酯交换反应更有效。当挠性二醇是1，3-丙二醇或1，4-丁二醇而不是乙二醇时，用该催化剂获得更好的颜色和更高的分子量。