溶液法制备PLA/改性长石复合材料及其性能表征

摘要

Modified feldspar was prepared by surface wet modification of feldspar from Hami with KH570 via solution.PLA/modified feldspar composites were prepared with modified feldspar as filler.The properties and structure of PLA/modified feldspar composites were characterized and analyzed.Interface contact angle measurement showed that compared with the original feldspar,the modified interface contact angle of the feldspar was increased,which showed that the surface of modified feldspar particle was hydrophobic and coincided with the FT-IR analysis.The mechanical properties showed that maximum tensile stress of PLA composites was improved when the loading content of modified feldspar was 5 wt％.TGA showed that the heat decomposition temperature increased by 4.47 ℃ compared with that of the PLA matrix,which showed the thermal stability was increased.DSC results showed that KH570 modified feldspar eliminated the cold crystallization process,and obviously promoted the crystallinity,which was supported by XRD analysis.The results showed that the KH570 modified feldspar played a heterogeneous nucleation role in accelerating the crystallization process of PLA matrix.%以KH570为改性剂对哈密长石进行湿法表面改性.以改性长石作为填料,通过溶液法制备了PLA/改性长石复合材料,对其性能及微观结构进行了测试和表征.界面接触角测试表明,经改性后界面接触角明显增大,表面有机憎水,具有亲油性,与FT-IR分析结果相吻合;力学性能测试表明,5％改性长石的加入有助于改善PLA复合材料的拉伸强度;TGA分析表明PLA/改性长石复合材料的热分解温度比PLA基体提高了4.47℃,表明其热稳定性得以提高;DSC分析表明,改性长石可以消除PLA复合材料的冷结晶,有助于提高PLA复合材料的结晶度,与XRD分析相吻合.测试结果表明,改性长石在PLA基质中起到了异相成核的作用,促进了PLA基质的结晶.