Physical, mechanical and thermal properties of low-density polyethylene reinforced with PET-coated SBS paperboard shavings applying different processing conditions

ABSTRACT Awareness about environmental problems has generated interest in the research for new materials in line with the sustainability principles. The recycling of industrial solid waste has contributed to the transformation of environmental liabilities into new products with added commercial value. In this study, the physical, me-chanical and thermal properties of low-density polyethylene (LDPE) composites reinforced with polyeth-ylene terephthalate (PET)-coated solid bleached sulfate (SBS) paperboard shavings were investigated ac-cording to composite formation process variables: preparation temperature, mean particle diameter of com-ponents and reinforcement concentration. Very few studies on the characterization of composites reinforced with PET-coated SBS paperboard shavings have been reported to date. The analyses were carried out based on standard methods published by the American Society for Testing and Materials. The results indicate an increase in the moisture content and water absorption occurred as a function of the increase in the rein-forcement. With regard to the density, there was no significant influence of variations in the granulometry or concentration of the PET-coated SBS paperboard shavings. Composites formed with particles of 0.73 mm at 140 ºC presented satisfactory tensile and flexural strength, compared with the values for the LDPE resin. Composites with 20% reinforcement formed by particles of 4.05 mm at 140 ºC showed 14% improvement in impact resistance properties. The thermal analysis indicated that shavings degradation occurred at 190 °C. Thus lower temperatures need to be applied in the processing of this composite material. The processing conditions of the composites resulted in different performance for each evaluated property. The use of the composite in manufacturing products must follow the process conditions that will provide to material the desirable level of properties for the best performance of the final product.

摘要：随着社会对环境问题的关注度日益提升，符合可持续发展原则的新型材料研究逐渐成为热点。工业固体废物的回收利用，可将原本的环境负担转化为具备商业附加值的新型产品。本研究针对以经聚对苯二甲酸乙二醇酯（PET）涂布的漂白硫酸盐纸板（solid bleached sulfate，SBS）刨花作为增强相的低密度聚乙烯（LDPE）复合材料，围绕制备温度、组分平均粒径及增强相添加浓度等成型工艺变量，系统探究了该复合材料的物理、力学及热学性能。截至目前，针对PET涂布SBS纸板刨花增强复合材料的性能表征相关研究尚不多见。
本次测试均遵循美国材料与试验协会（American Society for Testing and Materials）发布的标准方法开展。结果表明，复合材料的含水率与吸水率随增强相添加量的增加而升高；就密度而言，PET涂布SBS纸板刨花的粒径与添加浓度变化对其无显著影响。在140℃下采用0.73mm粒径组分制备的复合材料，其拉伸与弯曲性能相较于纯LDPE树脂表现优异；在140℃下采用4.05mm粒径组分制备且增强相添加量为20%的复合材料，其抗冲击性能提升了14%。热分析结果显示，纸板刨花的降解温度为190℃，因此该复合材料的加工需采用更低的工艺温度。
复合材料的加工工艺条件对各项性能指标存在差异化影响。将该复合材料用于产品制造时，需匹配能够使材料达到目标性能水平的工艺条件，以保障最终产品的最优性能。