枣核/低密度聚乙烯复合材料的力学性能

Mechanical properties of jujube pit/linear low density polyethylene composites

为充分利用红枣精深加工产生的废弃物,以枣核(JP)和低密度聚乙烯(LLDPE)为主要材料,采用注塑成型法制备JP/LLDPE复合材料,并对其静态力学性能(拉伸、弯曲和冲击)和动态力学性能(动态黏弹性、蠕变行为和应力松弛行为)进行系统测试分析。静态力学性能分析表明,随JP含量的增加,JP/LLDPE复合材料的拉伸强度和冲击强度逐渐降低,但复合材料的弯曲强度得到明显的提升。当JP添加量为20wt%时,JP/LLDPE复合材料的弯曲强度最高,较纯LLDPE的弯曲强度提高63.57%;动态力学分析表明,JP含量的增加有利于提高JP/LLDPE复合材料的刚性、抗蠕变性能和抗应力松弛性能,而温度的升高会对JP/LLDPE复合材料的抗蠕变性能和抗应力松弛性能产生不利的影响。

In order to make full use of the waste generated during the deep processing of red jujube, jujube pit(JP)and linear low density polyethylene(LLDPE) composites were prepared by injection molding method with JP and LLDPE as the main components. The static mechanical properties(tensile, flexural and impact) and dynamic mechanical properties(dynamic viscoelastic, creep behavior and stress relaxation behavior) were fully tested and analyzed. The static mechanical properties analysis show that the tensile and impact strength of JP/LLDPE composites are decreased as the JP contents increase, while the flexural strength of the composites is obviously improved. When the addition contents of JP reach 20 wt%, the JP/LLDPE composite exhibit optimal flexural strength, which is 63.57%higher than that of pure LLDPE. Dynamic mechanical analysis confirms that the increase of JP contents is beneficial to improve the rigidity, creep resistance and stress relaxation of JP/LLDPE composites, but the increase of temperature adversely affects the creep resistance and stress relaxation resistance of JP/LLDPE composites.