Application of β-sheet proteins as a compatibilizer in injection molding of kenaf core/polypropylene composites

ABSTRACT

Injection-molding was performed using ethylene–propylene copolymer as the matrix by varying the physicochemical treatment of the reinforcement, i.e., core portion of kenaf stem that was dry-distilled and coated with or without β-sheet protein derivatives. Although dry distillation reduced the moisture content, the Charpy impact strength of the molded composites was low. When molding was performed using the fillers coated with β-sheet protein derivatives, especially coated with liquid silk (LS), a satisfactory Charpy impact strength of the molded composites was markedly gained. Thus, the β-sheet protein derivatives had potential to work as a compatibilizer. Coating the fillers with β-sheet proteins was also effective in suppressing the generation of silver streaks on the surface of composites and in preventing the occurrence of defective injection molding.

摘要

以乙烯丙烯共聚物为基体，通过改变增强体的物理化学处理，即红麻茎干的芯部进行注射成型，该芯部被干馏，并涂有或不涂有β片蛋白衍生物。干馏虽然降低了含水率，但复合材料的夏比冲击强度较低。当使用涂覆有β片状蛋白质衍生物，特别是涂覆有液态丝(LS)的填料进行模塑时，模塑复合材料的夏比冲击强度显著提高。因此，β片状蛋白质衍生物具有作为增容剂的潜力。在填料上涂覆β片状蛋白也有效地抑制了复合材料表面银条纹的产生，并防止了缺陷注射成型的发生。

KEYWORDS:

• Liquid silk
• feather keratin
• compatibilizer
• polypropylene
• kenaf
• composite

关键词:

• 液体丝
• 羽毛角蛋白
• 增容剂
• 聚丙烯
• 红麻
• 混合成的

Acknowledgments

The author would like to thank Mr. Nobuo Kuwabara of Gunma Sericultural Technology Center for supplying mulberry silkworms.