利用电磁动态注射机注射成型聚丙烯试样制品,并用热老化试验箱人工加速其试样的老化降解。对比分析了稳态注射和动态注射成型的聚丙烯试样制品热氧老化期间力学性能的变化规律,用红外光谱(FT-IR)分析了聚丙烯试样制品老化前后羰基含量的变化情况。研究结果表明,采用动态注射成型技术,不但可以提高聚丙烯制品的力学性能,而且还能有效提高制品的抗热氧老化性能。制品在热氧老化过程中,其力学性能保持率高于稳态注射成型的聚丙烯制品。采用振频为8Hz、振幅为0.10mm的动态注射成型的聚丙烯试样制品的抗热氧老化性能最好。
The polypropylene products were molded by the electromagnetic dynamic injection molding machine. Polypropylene was degraded by accelerated aging test with thermal aging test chamber. The variation laws for mechanical properties of polypropylene products molded by the steady injection and dynamic injection were studied separately during the thermal oxidation aging. The change of carbonyl content in the polypropylene products during the aging was also analyzed by FT-IR. The result shows that the dynamic injection molding can improve the mechanical properties and the anti-thermal oxidation aging properties of the polypropylene. During the process of thermal oxidation aging, the mechanical properties maintenance of dynamic injection molded products is higher than that of steady injection molded products. The anti-thermal oxidation aging properties of dynamic injection molded products are the best when the frequency is 8 Hz and the amplitude is 0.10 mm.