High molar mass polycarbonate is synthesized via a solution transcarbonation of bis(methyl salicyl) carbonate and bisphenol-A at temperatures between 60 and 160 °C without the removal of the condensate, allowing the incorporation of thermosensitive monomers into polycarbonate. Kinetic and equilibrium studies show that the polymerization is 20–30 times faster at 120 °C compared to 60 °C, whereas the equilibrium M_w increases from 11 × 10³ g mol⁻¹ at 120 °C to 16 × 10³ g mol⁻¹ at 60 °C. This polycondensation is characterized by very high equilibrium constants ranging from 0.8 × 10³ at 160 °C to 4.1 × 10³ at 60 °C, corresponding to standard enthalpies and entropies of polymerization: −19 kJ mol⁻¹ < ΔH⁰ < −11 kJ mol⁻¹ and 13 J mol⁻¹ K⁻¹ < ΔS⁰ < 28 J mol⁻¹ K⁻¹. Without removal of the condensate, the system is shown to be dynamic and completely reversible when changing the temperature. Good predictability of this polycondensation is reported, where only at very low starting monomer concentrations, the formation of cyclics leads to deviations from the predicted behavior.

中文翻译：

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使用双（甲基水杨基）碳酸酯（一种活性碳酸酯）通过动态溶液碳酸转移制备高摩尔质量聚碳酸酯

高摩尔质量聚碳酸酯是通过双（甲基水杨基）碳酸酯和双酚 A 在 60 至 160 °C 之间的温度下进行溶液碳酸转移合成的，无需去除冷凝物，从而允许将热敏单体掺入聚碳酸酯中。动力学和平衡研究表明，与 60 °C 相比，120 °C 下的聚合速度快 20–30 倍，而平衡M _w从120 °C 下的11 × 10 ³ g mol ^-1增加到 16 × 10 ³ g mol ^-1在 60 °C。这种缩聚反应的特点是平衡常数非常高，范围从160 °C 时的0.8 × 10 ³到 4.1 × 10 ³在 60 °C，对应于标准聚合焓和熵：-19 kJ mol ^-1 < Δ H ⁰ < -11 kJ mol ^-1和 13 J mol ^-1 K ^-1 < Δ S ⁰ < 28 J mol ^-1 K ^-1。在不去除冷凝液的情况下，系统显示出在改变温度时是动态的和完全可逆的。据报道，这种缩聚反应具有良好的可预测性，只有在非常低的起始单体浓度下，环的形成才会导致与预测行为的偏差。