A Potential Alternative to Polystyrene: Ring-opening Terpolymerization of Different Epoxides with Phthalic Anhydride Using Metal-free Dual Catalysts

A series of semi-aromatic polyesters named as Poly(PO-CHO-PA)were facilely synthesized via ring-opening terpolymerization of bio-based cyclohexane oxide(CHO)/propylene oxide(PO)/phthalic anhydride(PA)using economical U1/PPNCI as dual catalyst.The proportion of CHO-PA and PO-PA segments in polymer can be readily altered by changing the feed ratio of CHO/PO because the reactivity ratios of CHO and PO with PA calculated by Fineman-Ross method are comparable.All synthesized amorphous polyesters with various compositions show one Tg ranging from 62 ℃ to 133 ℃.Significantly,the mechanical,thermal and barrier properties of these amorphous semi-aromatic polyesters are also adjustable and investigated for the first time.The results indicate the semi-polyesters exhibit superior thermostability(T5％ranging from 306 ℃ to 323 ℃)and high tensile strength(40.21-55.7 MPa)that is comparable with polystyrene(PS).Furthermore,Poly(PO-CHO-PA)films possess a promising prospect as packaging materials because of its colorless and highly transparent nature,along with low oxygen and water vapor transmission rate.All above performances may guarantee its potential alternative to commercial PS.