Long-Chain Branched Bio-Based Poly(butylene dodecanedioate) Copolyester Using Pentaerythritol as Branching Agent: Synthesis, Thermo-Mechanical, and Rheological Properties

The introduction of long-chain branched structures into biodegradable polyesters can effectively improve the melt strength and blow-molding properties polyesters. In this study, pentaerythritol (PER) was used as a branching agent to synthesize poly(butylene dodecanedioate) (PBD), resulting polymers were characterized by Nuclear Magnetic Resonance Proton Spectra (1H NMR) Fourier Transform Infrared spectroscopy (FT-IR). It found that small amount PER (0.25–0.5 mol%) generate even crosslinking structures. Both impact tensile modulus be greatly improved agent. With 1 mol% content in PBD, notched PBD has been increased 85%, 206%. Wide-angle X-ray diffraction differential scanning calorimetry results showed PER-branched PBDs exhibited crystallization ability compared with linear PBDs. Dynamic viscoelastics revealed shear-thickening behaviors for all under low shear rates.