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

Ruixue Niu; Zhening Zheng; Xuedong Lv; Benqiao He; Sheng Chen; Jiaying Zhang; Yanhong Ji; Yi Liu; Liuchun Zheng

doi:10.3390/polym15153168

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

Polymers (Basel). 2023 Jul 26;15(15):3168. doi: 10.3390/polym15153168.

Authors

Ruixue Niu^{1

2}, Zhening Zheng³, Xuedong Lv¹, Benqiao He¹, Sheng Chen⁴, Jiaying Zhang¹, Yanhong Ji¹, Yi Liu¹, Liuchun Zheng^{1

5}

Affiliations

¹ School of Textile Science and Engineering, Tiangong University, Tianjin 300387, China.
² Hebei Tieke Yichen New Materials Technology Co., Ltd., Shijiazhuang 050000, China.
³ Department of Applied Biology and Chemical Technology, Faculty of Science Hong Kong Polytechnic University, Hong Kong 100872, China.
⁴ Technology Innovation Center of Risk Prevention and Control of Refining and Chemical Equipment for State Market Regulation, China Special Equipment Inspection and Research Institute, Beijing 100029, China.
⁵ School of Chemical Engineering and Technology, Xinjiang University, Urumqi 830046, China.

Abstract

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

Keywords: biodegradable; branched; mechanical properties; poly(butylene dodecanedioate); polyester; rheological properties.

Grants and funding

National Natural Science Foundation of China (Grant Nos. 52173009 and 81971711) and the TGU Grant for Fiber Studies (Grant No. TGF-21-A9).