Mica-stabilized polyethylene glycol composite phase change materials for thermal energy storage

Mica was used as a supporting matrix for composite phase change materials(PCMs)in this work because of its distinctive morphology and structure.Composite PCMs were prepared using the vacuum impregnation method,in which mica served as the supporting material and polyethylene glycol(PEG)served as the PCM.Fourier transform infrared and X-ray diffraction analysis confirmed that the addition of PEG had no effect on the crystal structure of mica.Moreover,no chemical reaction occurred between PEG and mica during the vacuum impregnation process,and no new substance was formed.The maximum load of mica-stabilized PEG was 46.24%,the phase change temperature of M₄₀₀/PEG was 46.03℃,and the latent heat values of melting and cooling were 77.75 and 77.73 J·g^?1,respectively.The thermal conductivity of M₄₀₀/PEG was 2.4 times that of pure PEG.The thermal infrared images indicated that the thermal response of M₄₀₀/PEG improved relative to that of pure PEG.The leakage test confirmed that mica could stabilize PEG and that M₄₀₀/PEG had great form-stabilized property.These results demonstrate that M₄₀₀/PEG has potential in the field of building energy conservation.     

交联PE废旧料的回收方法及可逆交联高分子的研究进展

随着我国国民经济的快速发展，不可逆交联聚乙烯(XLPE)在日常生活中的应用越来越广泛，但同时也产生了大量的废旧料。通过不可逆化学键形成的XLPE交联结构很难被破坏，导致其加热难熔融、难以循环加工，因此XLPE废旧料回收困难，再生利用率低，并且造成了严重的环境污染。近年来发展起来的可逆交联技术通过在高分子中引入动态化学键形成分子链交联结构，使其在特定物理场下可以解除交联结构，从而具备可回收性和再加工性。本文综述了XLPE的传统回收方法和可逆交联高分子的研究进展，总结了XLPE回收方法的优点和局限性，重点介绍了解离型反应和缔合交换型反应在制备动态交联高分子材料中的应用。     

淀粉/聚乙烯薄膜中聚乙烯的降解特性研究

对含３０％淀粉的淀粉／聚乙烯薄膜进行环境降解、环境生物降解和环境曝晒试验,发现淀粉／聚乙烯薄膜在环境中暴晒降解的速度远远大于生物降解的速度,在应用环境中经过４周的降解,薄膜中聚乙烯的分子量损失达６２．５％;经５周的曝晒降解后,薄膜中聚乙炮的分子量损失达８７．５％;薄膜降解后,平板流变粘度降低２个数量级以上。