Synthesis Of Ester-terminated Hyperbranched Polyesters And The Investigation Of Their Properties

Hyperbranched polymers (HBPs), are highly branched macromolecules withthree-dimensional, dendritic, globular architecture. It attracts more and morescientific and engineering attention these year s because of its unique physicaland chemical properties, such as a large population of functional groups, lowersolution or melt viscosity, and better solubility owning to their specialtopological structure. As one of the most important members of hyperbranchedpolymers, hyperbranched polyester acquired important applications in manyfields, like coating, resin, drug carrier, polymer blending. In this article, a seriesof ester-terminated aromatic hyperbranched polyesters were synthesized by usingbenzene1.2.4-tricarboxylic1.2–anhydride (BTAA), dihydroxy alcohols andmethanol… The plasticizing effect of these hyperbranched polyesters to PVCwere also investigated.A series of hyperbranched polyesters were synthesized by using benzene1.2.4-tricarboxylic1.2–anhydride (BTAA), dihydroxy alcohols and methanolthrough one-pot reaction. HBPE-1, HBPE-2HBPE-3were obtained when themolar ratio of dihydroxy alcohols and BTAA were1:1,1.1:1,1.2:1. Thesolubility investigation showed that it was easy for hyperbranched polyester todissolve in THF, DFM and DMSO, and the hyperbranched polyester was solublein DOP but insoluble in ethanol and methanol. The structure of HBPEs werecharacterized by FT-IR and1H-NMR. The degree of branching of HBPEs werecalculated by1H-NMR. The molecular weight and PDI of HBPEs werecharacterized by GPC. The Tg of HBPEs were characterized by DSC. Thethermostability of HBPEs were characterized by TGA. It was found that whenthe molar ratio of dihydroxy alcohols and BTAA was1.1:1, the HBPE-2hadhigher degree of branching, lower Tg, better thermostability, bigger molecularweight and wide molecular weight distribution.The HBPE-2was used as plasticizer of PVC competing with traditionalplasticizer DOP. The plasticizing efficient was characterized by DSC, TGA,elongation at break, impact strength, SEM. It was found that HBPE had the bestplasticizing effect when the concentration of plasticizer was not exceeding than30%. When the concentration of plasticizer was40%, the blends of HBPE andDOP had the best plasticizing effect. The volatility test and liquid phaseextractability test showed that there was no migration when HBPE was used as plasticizer in PVC, indicating that HBPE could be used as a substitution for DOP.