Copolymerization Of Propylene Oxide, CO₂ And Phthalic Anhydride Catalyzed By DMC With Co-complexing Agents Incorporated Via Ball Milling

Polycarbonate synthesized with carbon dioxide and epoxides, is the most widely used environmental polymer, which has good thermal stability, mechanical property,biocompatibility, biodegradability, etc. However, there are still some problems in the ring-opening polymerization of cyclic anhydrides, CO2 and epoxides, such as low catalytic activity, low number-average molecular weight, narrow molecule weight distribution, etc. Therefore, the design and development of effective catalyst applied in the ring-opening polymerization of cyclic anhydrides, CO2 and epoxides has become the research hotspot.This article includes following aspects:First,(co-CA)Zn-Ni DMC and(co-CA)Zn-Co DMC were prepared via mechanical ball milling method using K3[Co(CN)6]?K2Ni(CN)4, Zn Cl2, co-CAs(PEG,PPG, PTMEG, PEG-PPG-PEG) and a small amount of auxiliary complexing agent(t Bu OH). And they were characterized by infrared(IR), elemental-analysis(EA),scanning-electron-microscope(SEM), X-Ray diffraction(XRD) and Thermal Gravity Analysis(TGA). The results showed that the(co-CA)Zn-Ni DMC and(co-CA)Zn-Co DMC catalysts incorporated with co-CAs were lower crystallinity and amorphous.Second, PA-PO polyester was prepared by the ring-opening copolymerization of phthalic anhydride and propylene oxide catalyzed by(co-CA)Zn-Ni DMC. The polyester were catalyzed by IR, 1H-NMR, 13C-NMR, gel permeation chromatography(GPC). The results showed that these polyesters were alternating copolymer. And DMC incorporated with different copolymerization complexing agent enhanced the good catalytic activity. The obtained polyester exhibithighest yield(90.79%) and poly(PO-co-PA)content(95.5%).Third, copolymerization of CO2, acid anhydride(phthalic anhydride(PA), maleic anhydride(MA), succine anhydride(SA)) and propylene oxide(PO)was catalyzed by(co-CA)Zn-Co DMC. The polyesters were characterized by IR,1H-NMR, GPC. The results showed that polyesters were successfully catalyzed by(co-CA)Zn-Co DMC. And the number-average molecular weight of polymers varied from 2.2×103 to 4.0×103, and molecular weight distribution varied from1.03 to 1.22.Fourth, the copolymerization of acid anhydride(PA, MA, SA) and propylene oxide(PO) was catalyzed by the(co-CA)Zn-Co DMC. The characterization of the results showed that the number-average molecular molecular weight of polyesters varied from 2.2×103 to 3.0×103, and molecular weight distribution(PDI) varied from1.03 to 1.18.Overall, the DMC catalysts prepared by mechanochemistry is a green,convenient and rapid method, DMC incorporated with different copolymerization complexing agents has the good catalytic activity in the copolymer copolymerization of carbon dioxide, anhydride and propylene oxide.