Synthesis and Ultraviolet Resistance of Macromolecule Ultraviolet Absorbents

2-Hydroxy-4(2,3-epoxypropoxy) benzophenone (HEB) was prepared by the reaction of 2,4-dihydroxybenzophenone (DBP) with epichlorohydrin. The structure of HEB was characterized by ¹H-NMR, FT-IR, UV spectroscopy, respectively. Continuous feeding method of propylene oxide (PO) that obviously increased the apparent concentration of HEB was used to overcome the problem of low reactivity ratios of HEB during the terpolymerization of HEB with PO and CO₂. Polymeric UV-absorbent （PPCH） with number-average molecular weight of 3.0×10⁴, polydispersity index of 4.77 and HEB mol ratio of 0.9% was successfully synthesized. To show the advantage of anti-UV irradiation performance of this PPCH, PPC/DBP blends and PPC/PPCH blends with similar HBP (2-hydroxybenzophenone) mass fraction were prepared for 120 h of xenon-arc weathering. The apparent number-average molecular weight of PPC/DBP blends decreased by 36%, accompanied by tensile strength loss of 26.4%, while the apparent number-average molecular weight of PPC/PPCH blend decreased by only 13.4%, accompanied by insignificant tensile strength loss of 3.6%. The migration resistance of UV absorber in PPC/PPCH was confirmed, where PPC blend with the similar DBP content was used as a reference for hot water (50 ℃) extraction test for 120 h, few UV absorbers were extracted in PPCH providing stable UV absorption performances, while the PPC/DBP blend showed sharp drop in UV absorption upon the extraction of hot water. Therefore, the macromolecule-based of ultraviolet-absorbers are an effective way to solve the problems of external migration of ordinary small molecular UV absorbers.