Thermo-Mechanical Properties of Polypropylene Composites Filled with Recycled Office Waste Paper

ABSTRACT

The high production of paper, followed by a more significant concern with environmental and economic issues, has led to greater relevance to paper recycling and its raw uses as composite filler. Composites of polypropylene with 10, 20, and 30 wt.% of recycled office waste paper were produced by injection molding and characterized by mechanical and thermal properties. All composites presented a slight reduction of 15°C in thermal stability compared to the polymeric matrix. Moreover, as the filler amount increased, the degree of crystallinity was reduced proportionally. The mechanical test showed similar tensile strength values among neat polymer andcomposites but also showed an increase in the composite’s tensile modulus, related to the stiffness of the natural filler. The composite with a higher percentage of waste paper (30 wt.%) maintained equivalent properties as neatpolypropylene and other composites (10 and 20 wt.%). Thus, 30 wt.% composites proved to be an excellent material with less synthetic polymer percentage, keeping thermal and mechanical properties comparable to the neat PP.Furthermore, this composite does not need chemical treatment or additives harmful to the environment. It is suitable for future applications in various plastic products such as packaging and domestic utensils.

摘要

纸张的高产量, 以及对环境和经济问题的更大关注, 使得纸张回收及其作为复合填料的原始用途更加相s关. 聚丙烯与10、20和30重量%的回收办公废纸的复合材料通过注射成型生产, 并通过机械和热性能进行表征. 与聚合物基体相比, 所有复合材料的热稳定性略微降低15℃. 此外, 随着填料量的增加, 结晶度成比例地降低. 机械试验表明, 纯聚合物和复合材料之间的拉伸强度值相似, 但复合材料的拉伸模量也有所增加, 这与天然填料的刚度有关. 废纸百分比较高 (30重量%) 的复合材料保持与纯聚丙烯和其他复合材料 (10和20重量%) 相同的性能. 因此, 30重量%的复合材料被证明是一种合成聚合物百分比较少的优异材料, 保持了与纯PP相当的热性能和机械性能. 此外, 这种复合材料不需要化学处理或对环境有害的添加剂. 它适用于包装和家用器具等各种塑料产品的未来应用.

KEYWORDS:

• Waste paper
• polypropylene
• composite
• recycling
• thermal properties
• mechanical properties

关键词:

• 废纸
• 聚丙烯
• 混合成的
• 回收
• 热性能
• 机械性能

Acknowledgments

The authors would like to express their gratitude to Carolina Fumico Araujo and Daniela Luche for their support.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Ethical approval

We confirm that all the research meets ethical guidelines and adheres to the legal requirements of the study country. The research does not involve any human or animal welfare related issues.

Additional information

Funding

This research was supported by the São Paulo State Research Support Foundation (FAPESP) under grant #2019/02607-6; São Paulo Research Foundation (FAPESP) [2019/02607-6]. This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – Brasil (CAPES) – Finance Code 001 and 88887.495399/2020-00.