In this study, cellulose microparticle were prepared by sulfuric acid hydrolysis, glyoxal crosslinking and acetylation followed by air classifying mill, and their properties including chemical structure, particle size, appearance and crystallinity were investigated. The effect of cellulose microparticle properties on characteristics of polypropylene (PP) biocomposite, such as physical, thermal and mechanical properties, was also examined. The glyoxal crosslinking enhanced the brittleness of pulp fiber, resulting in smallest particle size of cellulose microparticle and thus less entanglement in the polymer matrix. When cellulose microparticle were incorporated into PP, the crystallinity of biocomposite decreased, irrespective of microfiber type due to interference crystallization during crystal growth. Additionally, glyoxal crosslinked cellulose microparticle decreased the crystallization temperature of biocomposite, which is different from the other types of cellulose microparticle. The good dispersibility and brittleness of glyoxal crosslinked cellulose microparticle contributed to enhanced mechanical properties of biocomposite compared to the other cellulose microparticle added biocomposites.

本研究采用硫酸水解、乙二醛交联和乙酰化，再经空气分级磨制备纤维素微粒，对其化学结构、粒径、外观和结晶度等性质进行了研究。还检查了纤维素微粒性能对聚丙烯 (PP) 生物复合材料特性的影响，例如物理、热和机械性能。乙二醛交联增强了纸浆纤维的脆性，导致纤维素微粒的粒径最小，因此在聚合物基质中的缠结更少。当纤维素微粒掺入 PP 时，由于晶体生长过程中的干扰结晶，生物复合材料的结晶度降低，与微纤维类型无关。此外，乙二醛交联纤维素微粒降低了生物复合材料的结晶温度，这与其他类型的纤维素微粒不同。与其他添加纤维素微粒的生物复合材料相比，乙二醛交联纤维素微粒的良好分散性和脆性有助于提高生物复合材料的机械性能。