Jin Kailong, Kim Sung-Soo, Xu Jun, Bates Frank S, Ellison Christopher J
Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, United States.
ACS Macro Lett. 2018 Nov 20;7(11):1339-1345. doi: 10.1021/acsmacrolett.8b00685. Epub 2018 Oct 17.
Melt blowing is a process in which liquid polymer is extruded through orifices and then drawn by hot air jets to produce nonwoven fibers with average diameters typically greater than one micron. Melt-blown nonwoven fiber products constitute a significant fraction (i.e., more than 10%) of the $50 billion global nonwovens market. Thermoplastic feedstocks, such as polyethylene, polypropylene, poly(phenylene sulfide), and poly(butylene terephthalate), have dominated melt-blown nonwovens because of their combined cost, good chemical resistance, and high-temperature performance. Cross-linked nonwovens from other commodity polymers (e.g., (meth)acrylates, styrenics, silicones, etc.) could be attractive alternatives; however, no commercial cross-linked nonwovens currently exist. Here, cross-linked fibers were produced via one-step melt blowing of thermoreversible Diels-Alder polymer networks comprised of furan- and maleimide-functional methacrylate-based polymer backbones. These dynamic networks de-cross-link and flow like viscous liquids under melt-blowing conditions and then revert to a network via cooling-induced cross-linking during/after melt blowing. Finally, the resulting cross-linked fibers can be recycled after use because of their reversible dynamic nature, which may help address microfiber waste as a significant source of microplastic pollution.
熔喷是一种将液态聚合物通过喷丝孔挤出，然后由热空气射流拉伸以生产平均直径通常大于一微米的非织造纤维的工艺。熔喷非织造纤维产品在全球500亿美元的非织造布市场中占很大比例（即超过10%）。热塑性原料，如聚乙烯、聚丙烯、聚苯硫醚和聚对苯二甲酸丁二醇酯，由于其综合成本、良好的耐化学性和高温性能，在熔喷非织造布领域占据主导地位。来自其他通用聚合物（如（甲基）丙烯酸酯、苯乙烯类、有机硅等）的交联非织造布可能是有吸引力的替代品；然而，目前尚无商业交联非织造布。在此，通过一步熔喷由呋喃和马来酰亚胺官能化的甲基丙烯酸酯基聚合物主链组成的热可逆狄尔斯-阿尔德聚合物网络来制备交联纤维。这些动态网络在熔喷条件下会解交联并像粘性液体一样流动，然后在熔喷期间/之后通过冷却诱导交联恢复为网络。最后，由于其可逆的动态性质，所得的交联纤维在使用后可以回收利用，这可能有助于解决作为微塑料污染重要来源的微纤维废物问题。
