In this study the advantages of using bio-based multi-functional malonic acid salt as chain extender in preparing closed cell polyurethane foams is demonstrated. We found that the presence of malonic acid salt can alter the reaction kinetics, segmental mobility and hence the relative kinetics of polyurethane and polyurea formation. By analyzing the infrared active vibrations, it is demonstrated that the formation of urethane and urea linkages is accelerated at the initial stage of reaction, resulting in enhanced viscosity build-up attributed to the catalytic activity of the triethylamine complexed with malonic acid. The relative kinetics in formation of different morphological features thus can be used to control the cell opening process. These results, combining information on polymerization kinetics, gas evolution and phase separation, illustrate the capability of using malonic acid salt as the chain extender to manipulate polyurethane foam morphology and its potential application in polyurethane closed cell foam systems.

在这项研究中，证明了在制备闭孔聚氨酯泡沫塑料中使用生物基多功能丙二酸盐作为扩链剂的优势。我们发现丙二酸盐的存在可以改变反应动力学，链段流动性，从而改变聚氨酯和聚脲形成的相对动力学。通过分析红外主动振动，表明在反应的初始阶段，氨基甲酸酯和尿素键的形成被加速，这归因于丙二酸与三乙胺配合的催化活性而导致的粘度增加。因此，可以使用形成不同形态特征的相对动力学来控制细胞的开放过程。这些结果结合了聚合动力学，气体逸出和相分离的信息，