Binley Gillian, Mekonnen Tizazu H
Department of Chemical Engineering, Institute of Polymer Research, Waterloo Institute of Nanotechnology, University of Waterloo, Waterloo, Ontario, Canada.
Macromol Rapid Commun. 2025 Sep;46(17):e2500276. doi: 10.1002/marc.202500276. Epub 2025 Jul 10.
This study utilized the chain-scission capability of peroxides, such as aqueous hydrogen peroxide (HO), to induce controlled degradation of poly(butylene adipate-co-terephthalate)(PBAT) through reactive batch mixing with the objective of increasing the melt flow index (MFI). The effects of the peroxide concentration and processing time were examined, and the results showed that concentration had the greatest impact, with an approximate 450% increase in MFI at the optimal peroxide concentration. On the other hand, the peroxide treatment had a minimal impact on crystallinity and thermal properties. Degradation was deemed to occur chiefly via random chain scission with contributions from heat and hydrolysis, as supported by proton nuclear magnetic resonance spectroscopy (HNMR). The treated PBAT sample showed promise in melt-blown micro-fiber production, producing fibers with a 68% smaller average diameter than that of the untreated PBAT. The treated PBAT was then blended with various levels of high MFI poly(lactic acid) (PLA) to optimize properties and cost of the resulting micro-fiber material. As expected, the blends demonstrated increased tensile strength and decreased elongation at break with higher PLA contents, up to 30% and 13%, respectively, successfully balancing the material properties of the PBAT starting material. Despite these favorable tensile properties, the material blend remained suboptimal due to evidence of phase separation. To bridge this incompatibility, maleation was implemented, resulting in a polymer characterized by improved homogeneity, thereby enabling the production of uniform fibers without compromising desired tensile properties. The melt-blowing generated PBAT-PLA micro-fibers can have applications as a sustainable alternative for polypropylene-dominated HVAC air filters, medical masks, etc.
本研究利用过氧化物（如过氧化氢水溶液（HO））的断链能力，通过反应性间歇混合诱导聚（己二酸丁二醇酯-对苯二甲酸丁二醇酯）（PBAT）的可控降解，目的是提高熔体流动指数（MFI）。研究了过氧化物浓度和加工时间的影响，结果表明浓度影响最大，在最佳过氧化物浓度下MFI提高了约450%。另一方面，过氧化物处理对结晶度和热性能的影响最小。如质子核磁共振光谱（HNMR）所示，降解主要通过随机断链发生，伴有热和水解的作用。经处理的PBAT样品在熔喷微纤维生产方面显示出前景，生产出的纤维平均直径比未处理的PBAT小68%。然后将经处理的PBAT与不同含量的高MFI聚乳酸（PLA）共混，以优化所得微纤维材料的性能和成本。正如预期的那样，共混物的拉伸强度随着PLA含量的增加而提高，断裂伸长率降低，分别提高了30%和降低了13%，成功地平衡了PBAT原料材料的性能。尽管具有这些良好的拉伸性能，但由于存在相分离的迹象，材料共混物仍不理想。为了弥合这种不相容性，进行了马来酸化处理，得到了一种具有改善均质性的聚合物，从而能够生产出均匀的纤维，同时不影响所需的拉伸性能。熔喷产生的PBAT-PLA微纤维可作为以聚丙烯为主的暖通空调空气过滤器、医用口罩等的可持续替代品。
