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采用微注塑(MIM)分别成型厚度为0.7 mm的聚丙烯(PP)制品及其与埃洛石纳米管(HNT)的复合材料制品(μ-PP和μ-PP/HNT),采用普通注塑(CIM)成型厚度为3.5 mm的PP制品(m-PP),研究了制品力学性能与晶体结构之间的关系以及HNT对制品力学性能和热稳定性的影响.结果表明,与m-PP制品相比,μ-PP制品的拉伸强度和储能模量(40℃)分别提高67%和48%,这是由于μ-PP制品的结晶度(76.7%)和剪切层厚度(占制品半壁厚的57.8%)明显较高所致.少量(2 phr)HNT的加入可进一步提高μ-PP制品的拉伸强度、储能模量和热稳定性,这主要得益于HNT能均匀分散于PP基体中.虽然μ-PP和μ-PP/HNT制品β晶含量(20.0%和26.3%)显著高于m-PP制品β晶含量(8.5%),但前两种制品的断裂伸长率却明显较低,这表明该2种制品中因分子链取向所致的韧性降低效应明显强于β晶的增韧效应.
Polypropylene (PP) and its composites (μ-PP and μ-PP / HNT) with halloysite nanotubes (HNT) were molded by microinjection molding (MIM) CIM) was used to fabricate PP product (m-PP) with a thickness of 3.5 mm. The relationship between the mechanical properties and the crystal structure of the product and the effect of HNT on the mechanical properties and thermal stability of the product were investigated. The tensile strength and storage modulus (40 ℃) of μ-PP products increased by 67% and 48% respectively because of the crystallinity (76.7%) and the thickness of the shear layer Thick 57.8%) was significantly higher.Adding a small amount of (2 phr) HNT can further improve the tensile strength, storage modulus and thermal stability of μ-PP products, mainly due to HNT can be evenly dispersed in PP matrix.While the β crystal content (20.0% and 26.3%) in μ-PP and μ-PP / HNT products is significantly higher than that of m-PP products (8.5%), the elongation at break But it is obviously lower, which indicates that the ductility reduction effect of the two kinds of products due to the molecular chain orientation is obviously stronger than the toughening effect of β-crystal.