This study aims to assess and understand the accelerated weathering performance of injection moulded PP and LDPE composites reinforced with calcium rich waste resources for the first time. Two different calcium rich wastes: FGD gypsum and marble waste are incorporated without any chemical treatment in the polymer matrices. Visual appearance, chemical changes, flexural properties (strength, modulus and elongation) and surface morphology are analysed. Weathered surfaces are studied to analyse the structural changes with morphology by FTIR and SEM. LDPE showed higher visual stability by weathering with enhanced flexural properties for FGD gypsum composites. FTIR analysis revealed that the composites prepared with LDPE had a stabilizing effect on photo-degradation (minimum carbonyl index=1.09–1.14), which correlates well with the results of mechanical testing, showing these composites retained remarkable mechanical properties (retention rate>85%.) after weathering. Visual appearances, physical and mechanical properties of polymer composites are affected by the accelerated weathering condition. UV radiation in combination with temperature, humidity and water spray leads to polymer crystallinity with degradation resulting in weaker interfacial bonding and detachment of filler from matrix. Results show that the flexural strength of weathered FGD gypsum-PP, marble waste-PP and marble waste-LDPE composites decreased about 7–38%, 50–59% and 5–6%, respectively. Flexural strength of the weathered FGD gypsum-LDPE composites increased about 7–12%. The present study implies that both the reinforcements can enhance the properties of PP and LDPE composites after accelerated UV weathering exposure with potential for civil engineering applications. FGD gypsum is more prominent while structural and durability performances are taken into account.

本研究旨在评估和了解首次用富钙废物资源增强的注塑成型 PP 和 LDPE 复合材料的加速老化性能。两种不同的富含钙的废物：FGD 石膏和大理石废物未经任何化学处理就加入聚合物基质中。分析视觉外观、化学变化、弯曲特性（强度、模量和伸长率）和表面形态。研究风化表面以通过 FTIR 和 SEM 分析结构变化与形态。低密度聚乙烯通过风化显示出更高的视觉稳定性，并增强了 FGD 石膏复合材料的弯曲性能。FTIR 分析表明，用 LDPE 制备的复合材料对光降解具有稳定作用（最小羰基指数 = 1.09-1.14），这与机械测试的结果非常相关，表明这些复合材料在风化后仍保持显着的机械性能（保留率>85%）。聚合物复合材料的视觉外观、物理和机械性能受加速老化条件的影响。紫外线辐射与温度、湿度和喷水相结合会导致聚合物结晶和降解，从而导致界面结合力减弱以及填料与基体的分离。结果表明，风化脱硫石膏-PP、大理石废料-PP和大理石废料-LDPE复合材料的抗弯强度分别下降约7-38%、50-59%和5-6%。风化 FGD 石膏-LDPE 复合材料的弯曲强度增加了约 7-12%。本研究表明，在加速紫外线老化暴露后，这两种增强材料都可以增强 PP 和 LDPE 复合材料的性能，具有土木工程应用的潜力。FGD石膏在考虑结构和耐久性性能的同时更为突出。