聚(苯基壓克力)系之Fries重排反應及其做為紫外光安定劑之研究

Abstract

PET製品經常用於抽絲及製成薄膜，此類產品對於光氧老化之抵抗力總是較差的，本研究合成出兩種聚合物，將之和PET摻混，由於照光後皆有Photo Fries rearrangement的發生，而會有抑制PET之光氧老化現像，此兩個聚合物一為Poly(phenyl acrylate)─以下簡稱PPA；另一個為Poly(p-methylphenyl acrylate)─以下簡稱PMPA。首先利用FT-IR對於其不同UV光照射時數之PET摻混薄膜進行分析，由此來探討其斷鍵型式以及老化程度的差異，利用此方法來比較其光氧老化的安定效果，更可利用其FT-IR之相減圖結果來討論其重排反應之動力學。另外將PPA及PMPA分別和PET摻混後抽絲以進行照光，由其機械性質之衰減程度來比較其不同摻混比例的PPA及PMPA對PET的光氧老化之安定效果。

Poly(phenyl acrylate) (PPA) and poly(p-methylphenyl acrylate) (PMPA) weresynthesized and characterized. Upon irradiation of ultraviolet light, both PPAand PMPA underwent Photo Fries rearrangement, leading to the formation of a 6-membered ring structure of o-hydroxy phenone moieties. A first order of reactionof Photo Fries rearrangement was observed, with rate constant of 0.040 day-1 and 0.344 day-1. PPA and PMPA were then used as UV stabilizers for poly(ethylene tere-phthalate) (PET). 5% and 10% of PPA /or PMPA were respectively blended with PET. Fibers of the PPA/PET and PMPA/PET were spun, and irradiated with UV byusing an accelerated weathering tester (Q.U.V.). Experimental results revealedthat when incorporated with 5% of PPA or PMPA into PET, good stabilization wasfound, with PMPA exhibiting better retention of tensile strength after 42 daysof accelerated aging.