This work is aimed to study the application of a bio-based plasticizer, obtained by acetylation and epoxydation of cardanol, for the production of soft PVC foams. The use of epoxidized cardanol acetate allowed obtaining a more efficient foaming of soft PVC compared to phthalate plasticizer bis(2-ethylhexyl) phthalate (DEHP), mainly due to the lower viscosity attained in the decomposition range of azodicarbonamide (AZDC). As a consequence, the foams produced by epoxidized cardanol acetate showed a lower density compared to those produced with DEHP. The lower density yielded lower values of compressive modulus. However, the modulus was shown to be not only dependent on the density, but also showed a direct dependence on the type of plasticizer used, in addition to processing temperature and AZDC content. As a consequence, the specific compressive modulus also showed a direct dependence on the type of plasticizer, processing temperature and AZDC content. Such dependence was explained by considering different cellular morphologies developed during foaming under different processing conditions, including type of plasticizer. In particular, it was shown that the lower viscosity attained by epoxidized cardanol acetate plasticized PVC involved an increase of the average pore size of the foam, which was shown to be the main cause of the variation of the specific compressive modulus.

中文翻译：

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腰果酚衍生增塑剂制备软质PVC泡沫的压缩行为

本工作旨在研究通过腰果酚乙酰化和环氧化获得的生物基增塑剂在生产软质 PVC 泡沫中的应用。与邻苯二甲酸酯增塑剂邻苯二甲酸双（2-乙基己基）酯（DEHP）相比，环氧化腰果酚乙酸酯的使用允许获得更有效的软PVC发泡，这主要是由于在偶氮二甲酰胺（AZDC）的分解范围内获得的粘度较低。因此，与使用 DEHP 生产的泡沫相比，由环氧化腰果酚乙酸酯生产的泡沫显示出较低的密度。较低的密度产生较低的压缩模量值。然而，模量不仅取决于密度，而且还直接取决于所用增塑剂的类型，此外还取决于加工温度和 AZDC 含量。作为结果，比压缩模量还显示出直接依赖于增塑剂的类型、加工温度和 AZDC 含量。这种依赖性可以通过考虑在不同加工条件（包括增塑剂类型）下发泡过程中形成的不同细胞形态来解释。特别是，结果表明环氧化腰果酚乙酸酯增塑 PVC 获得的较低粘度涉及泡沫平均孔径的增加，这是比压缩模量变化的主要原因。