摘要
采用FT IR ,XPS ,凝胶分析以及熔融指数、接触角和力学性能测定 ,研究了不同紫外辐照光强对高密度聚乙烯 (HDPE)的化学结构、流动性、亲水性和辐照改性HDPE在HDPE/聚碳酸酯 (PC)共混体系中的增容效应的影响 .在相同辐照时间下 ,随紫外光强提高 ,引入HDPE分子链的含氧基团数量增加 ;在辐照过程中 ,紫外光强对HDPE的交联有显著影响 ,在较低光强 (32W/m2 )下辐照 2 4h的HDPE无凝胶生成 ,但在较高光强 (4 5和 78W/m2 )下辐照 2 4h后 ,HDPE产生凝胶 ,其含量随紫外光强提高而增多 ;与未辐照HDPE相比 ,较高光强下辐照HDPE的熔融指数有所下降 ,但其亲水性得到明显改善 ;紫外辐照改性HDPE对HDPE/PC体系有增容作用 ,随紫外光强提高其增容效应明显增强 .与未增容HDPE/PC(80 /2 0 )体系相比 ,加入 2 0 %辐照 2 4hHDPE(光强 78W/m2 )的HDPE/PC共混物的拉伸屈服强度从 2 6 3MPa提高到 30 2MPa ,缺口冲击强度从 5 1J/m提高到 15 8J/m .
Chemical structure, melt flow and hydrophilic properties of high density polyethylene (HDPE) functionalized by ultraviolet irradiation at different light intensity and compatibilization of the functionalized HDPE in HDPE/polycarbonate (PC) blend are studied through FT-IR, XPS, crosslinking, melt index (MI), contact angle with water and mechanical properties measurements. After ultraviolet irradiation, oxygen containing groups are introduced onto the HDPE chain, and the amount of the introduced groups increases with light intensity under the same irradiation time. The amount of oxygen containing groups on surface layer of the HDPE irradiated at 32, 45 and 78 W/m 2 for 72 h are 12.76%, 15.32% and 19.74%, respectively. The HDPE irradiated at lower light intensity (32 W/m 2) for 24 h is not crosslinked, and its MI increases. However, gelation takes place in the HDPE irradiated at higher light intensity (45 and 78 W/m 2) for 24 h, the gel content increases with increasing light intensity, and their MI are smaller than that of unirradiated HDPE. The contact angle with water of the irradiated HDPE decreases with light intensity. The compatibilization of the functionalized HDPE in HDPE/PC blend increases with light intensity. Compared with HDPE/PC (80/20) blend, the yield strength and notch impact strength of HDPE/HDPE irradiated at 78 W/m 2 for 24 h/PC (60/20/20) blend are increased from 26.3 MPa and 51 J/m to 30.2 MPa and 158 J/m, respectively.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
2002年第7期1353-1356,共4页
Acta Chimica Sinica
