This study investigates the effect of trimerization catalyst (mainly composed of potassium ethyl hexanoate) content (0.5–6 pphp) on the kinetics, chemical properties, and cellular morphology of poly(urethane-isocyanurate) rigid (PIR) foams. Increasing the trimerization catalyst content was found to accelerate the foaming process since all its characteristic times (cream time, gel time and tack-free time) were found to decrease (Δt_gel ∼ −85%). Increasing the trimerization catalyst content was also found to significantly increase the maximum temperature reached during foaming, from 122 to 162 °C. ATR-FTIR spectroscopy analysis of the foam samples demonstrated that increasing the trimerization catalyst level significantly increased the isocyanurate content of the PIR matrix, which corroborated the reduction of nonreacted isocyanate. Accelerating the chemical reactions was also found to decrease the foam density and the cell height significantly (Δρ_f ∼ −18% and Δh ∼ −47%, respectively), thus increasing the cell population density by more than a factor of 15 through the reduction of cell coarsening and Oswald ripening. Open cell content was kept very low with a value under 4% for all catalyst contents.

中文翻译：

---

增加三聚体化催化剂的用量如何影响聚氨基甲酸酯-异氰脲酸酯硬质泡沫的形成、异氰脲酸酯含量和微观结构


本研究研究了三聚体化催化剂（主要由己酸乙酯钾组成）含量 （0.5-6 pphp） 对聚氨基甲酸乙酯-异氰脲酸酯硬质 （PIR） 泡沫动力学、化学性质和细胞形态的影响。发现增加三聚体化催化剂含量会加速发泡过程，因为发现其所有特征时间 （奶油时间、凝胶时间和表干时间） 都减少了 （Δt_凝胶 ∼ -85%）。还发现，增加三聚体化催化剂的含量会显著提高发泡过程中达到的最高温度，从 122 °C 增加到 162 °C。泡沫样品的 ATR-FTIR 光谱分析表明，提高三聚体化催化剂水平会显著提高 PIR 基体的异氰尿酸酯含量，这证实了未反应的异氰酸酯的减少。还发现加速化学反应会显著降低泡沫密度和细胞高度（分别为 Δρ_f ∼ -18% 和 Δh ∼ -47%），从而通过减少细胞粗化和 Oswald 成熟，使细胞群密度增加 15 倍以上。开孔含量保持在非常低的水平，所有催化剂含量均低于 4%。