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.

Key words: HIGH-DENSITY POLYETHYLENE, POLYCARBONATE, ALLOY, MECHANICAL PROPETIES