The amount of plastic waste generated is causing damage to the environment, such as sea and soil pollution, and one of the alternatives for disposing of polymers is recycling. This work proposes recycling expanded polystyrene using a biodegradable solvent, its plastification with glycerol, and the preparation of the composite with post-consumer recycled gypsum for applications to manufacturing by 3D printing and for finishing materials for construction. Specimen for tensile testing and shore D hardness were prepared by injection process and by 3D printing. In addition, Thermogravimetric (TG), Fourier-transform infrared spectrometry (FTIR), Differential scanning calorimeter, Scanning electron microscope (FESEM) analyses, and flame propagation tests were also carried out. TG and FTIR analyses show that the recycling process did not degrade the material, and the addition of glycerol and gypsum improved the thermal stability of the composite. The mechanical properties of the injected and 3D printed samples with gypsum were similar, due to the dimensional stability of the manufactured filament, which improved the speed and quality of the specimen printing. The increase in ductility and the reduction in the glass transition temperature showed that the recycled expanded polystyrene (RPS) were effectively plasticized with the addition of 2 wt% glycerol, preserving their flame self-extinguishment when subjected to the flame propagation test. Due to these properties, the plasticized RPS can be used to manufacture articles for finishing in civil construction, and the RPS composite can be used to manufacture 3D printed prototypes.

Graphical abstract

中文翻译：

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用可生物降解的溶剂回收发泡聚苯乙烯以制造 3D 打印原型和建筑装饰材料

产生的塑料废物量正在对环境造成破坏，例如海洋和土壤污染，而处理聚合物的替代方法之一是回收利用。这项工作建议使用可生物降解的溶剂回收膨胀聚苯乙烯，用甘油对其进行增塑，以及使用消费后回收石膏制备复合材料，用于 3D 打印制造和建筑装饰材料。通过注射工艺和3D打印制备用于拉伸试验和肖氏D硬度的试样。此外，还进行了热重（TG）、傅里叶变换红外光谱（FTIR）、差示扫描量热仪、扫描电子显微镜（FESEM）分析和火焰传播测试。TG和FTIR分析表明，回收过程没有降解材料，甘油和石膏的添加提高了复合材料的热稳定性。由于制造的长丝的尺寸稳定性，石膏注射样品和 3D 打印样品的机械性能相似，从而提高了样品打印的速度和质量。延展性的增加和玻璃化转变温度的降低表明，添加 2 wt% 的甘油有效地增塑了再生发泡聚苯乙烯 (RPS)，在进行火焰传播测试时保持了其火焰自熄性。由于这些特性，增塑的 RPS 可用于制造用于土木建筑的精加工制品，

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