This investigation employed free radical melt grafting technology for the synthesis of (POE/R-LLDPE)-g-(GMA-co-St) graft copolymers. Subsequently, this graft copolymer was applied as a modifier for poly (butylene terephthalate) (PBT) resin. The effects of varying recycled linear low-density polyethylene (R-LLDPE) contents in the graft on the rheological behavior, thermal properties, mechanical properties, and toughening mechanism of PBT/(POE/R-LLDPE)-g-(GMA-co-St) blends were exhaustively explored. The findings revealed that glycidyl methacrylate (GMA) and styrene (St) were effectively grafted onto the poly (ethylene-octene) (POE) and R-LLDPE molecular chains. This process enabled the epoxy groups in the GMA of the graft to react with the terminal groups of the PBT resin, thereby enhancing its compatibility with PBT. The use of R-LLDPE-g-(GMA-co-St) or POE-g-(GMA-co-St) as singular modifiers did not produce optimal modification results. Conversely, the most effective modification of the PBT resin was observed when both were combined, indicating a pronounced synergistic modification effect. The optimal overall performance of the blend was noted when the R-LLDPE content in the graft copolymer was 50 wt%. This method significantly enhanced the toughness of the blend while preserving excellent thermal stability and mechanical strength, concurrently reducing the product cost. At this point, a high concentration of voids was observed in the stress-whitening area of the impact specimens. The PBT matrix displayed conspicuous shear yielding with a notably rough impact fracture surface, manifesting highly significant tough fracture characteristics.

中文翻译：

---

释放界面协同作用：原位多步反应诱导控制来自回收来源的高性能和功能性聚对苯二甲酸丁二醇酯/聚烯烃共混物


本研究采用自由基熔融接枝技术合成(POE/R-LLDPE)-g-(GMA-co-St)接枝共聚物。随后，将该接枝共聚物用作聚对苯二甲酸丁二醇酯（PBT）树脂的改性剂。接枝物中不同回收线性低密度聚乙烯（R-LLDPE）含量对PBT/(POE/R-LLDPE)-g-(GMA-co)流变行为、热性能、力学性能和增韧机理的影响-St) 混合物进行了详尽的探索。研究结果表明，甲基丙烯酸缩水甘油酯（GMA）和苯乙烯（St）有效地接枝到聚（乙烯-辛烯）（POE）和R-LLDPE分子链上。该过程使接枝物GMA中的环氧基团与PBT树脂的端基发生反应，从而增强了其与PBT的相容性。使用R-LLDPE-g-(GMA-co-St)或POE-g-(GMA-co-St)作为单一改性剂并没有产生最佳的改性结果。相反，当两者结合时，观察到对 PBT 树脂最有效的改性，表明显着的协同改性效果。当接枝共聚物中 R-LLDPE 含量为 50 wt% 时，共混物的整体性能达到最佳。该方法显着增强了共混物的韧性，同时保持了优异的热稳定性和机械强度，同时降低了产品成本。此时，在冲击试样的应力致白区域观察到高浓度的空隙。 PBT基体表现出明显的剪切屈服，冲击断裂面明显粗糙，表现出非常显着的韧性断裂特征。