In this work, a new class of fourth-generation, zero ozone depletion potential, hydrofluoroolefin-based blowing agents were used to prepare phenolic foam. While hydrofluoroolefin blowing agents have been used previously to prepare polyurethane foams, few studies have been reported on their use in phenolic foams. We introduce an effective method for foam preparation using two low-boiling blowing agents, cis-1,1,1,4,4,4-hexafluoro-2-butene and trans-1,1,1,4,4,4-hexafluoro-2-butene, and their combinations with hexane. Traditionally, phenolic foams have been prepared using chlorofluorocarbons and hydrochlorofluorocarbons, which can have harmful effects on the environment due to their high ozone depletion potential or global warming potential. Conductor-like screening model for real solvents (COSMO-RS) modeling studies were performed to understand the effects of different blowing agent combinations on their boiling points. A series of phenolic foams were prepared by varying the concentration of the hydrofluoroolefin and the hydrofluoroolefin–hexane blowing agent combinations. The concentrations of the surfactant, Agnique CSO 30, and the toughening agent, polyethylene glycol, were also varied to yield a formulation with the optimal properties. The foams formulated with the hydrofluoroolefin–hexane mixture displayed a higher compressive strength and a lower thermal conductivity than those prepared with either hydrofluoroolefin or hexane alone. The cell microstructure of all the foams was examined using scanning electron microscopy. By introducing flexible chains into the resin matrix, PEG facilitates proper distribution of hydrofluoroolefin–hexane blowing agents and other reagents and thereby increases the mechanical strength of the foam.

中文翻译：

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氢氟烯烃发泡剂制备酚醛泡沫及聚乙二醇的增韧作用


在这项工作中，使用了第四代新型、零臭氧消耗潜值、氢氟烯烃基发泡剂来制备酚醛泡沫。虽然氢氟烯烃发泡剂以前已用于制备聚氨酯泡沫，但很少有关于其在酚醛泡沫中使用的研究报道。我们介绍一种使用两种低沸点发泡剂顺式-1,1,1,4,4,4-六氟-2-丁烯和反式-1,1,1,4,4,4-制备泡沫的有效方法六氟-2-丁烯，以及它们与己烷的组合。传统上，酚醛泡沫是使用氯氟烃和氢氯氟烃制备的，由于其高臭氧消耗潜力或全球变暖潜力，可能对环境产生有害影响。进行了真实溶剂的类导体筛选模型 (COSMO-RS) 建模研究，以了解不同发泡剂组合对其沸点的影响。通过改变氢氟烯烃和氢氟烯烃-己烷发泡剂组合的浓度制备了一系列酚醛泡沫。表面活性剂 Agnique CSO 30 和增韧剂聚乙二醇的浓度也发生变化，以产生具有最佳性能的配方。与单独用氢氟烯烃或己烷制备的泡沫相比，用氢氟烯烃-己烷混合物配制的泡沫显示出更高的压缩强度和更低的导热率。使用扫描电子显微镜检查所有泡沫的泡孔微观结构。通过在树脂基质中引入柔性链，PEG 有助于氢氟烯烃-己烷发泡剂和其他试剂的适当分布，从而提高泡沫的机械强度。