Research on Properties of PBAT/CaCO3 Composite Films Modified with Titanate Coupling Agent

Zhekun Liu; Fantao Meng; Xianggang Tang; Chengzhuang Su; Qinglin Mu; Guannan Ju

doi:10.3390/polym15102379

Research on Properties of PBAT/CaCO₃ Composite Films Modified with Titanate Coupling Agent

Polymers (Basel). 2023 May 19;15(10):2379. doi: 10.3390/polym15102379.

Authors

Zhekun Liu¹, Fantao Meng¹, Xianggang Tang¹, Chengzhuang Su¹, Qinglin Mu¹, Guannan Ju¹

Affiliation

¹ School of Materials Science and Engineering, Shandong University of Technology, Zibo 255000, China.

Abstract

High cost, low crystallinity, and low-melt strength limit the market application of the biodegradable material poly (butylene adipate-co-terephthalate) (PBAT), which has become a major obstacle to the promotion of PBAT products. Herein, with PBAT as resin matrix and calcium carbonate (CaCO₃) as filler, PBAT/CaCO₃ composite films were designed and prepared with a twin-screw extruder and single-screw extrusion blow-molding machine designed, and the effects of particle size (1250 mesh, 2000 mesh), particle content (0-36%) and titanate coupling agent (TC) surface modification of CaCO₃ on the properties of PBAT/CaCO₃ composite film were investigated. The results showed that the size and content of CaCO₃ particles had a significant effect on the tensile properties of the composites. The addition of unmodified CaCO₃ decreased the tensile properties of the composites by more than 30%. TC-modified CaCO₃ improved the overall performance of PBAT/CaCO₃ composite films. The thermal analysis showed that the addition of titanate coupling agent 201 (TC-2) increased the decomposition temperature of CaCO₃ from 533.9 °C to 566.1 °C, thereby enhancing the thermal stability of the material. Due to the heterogeneous nucleation of CaCO₃, the addition of modified CaCO₃ raised the crystallization temperature of the film from 97.51 °C to 99.67 °C and increased the degree of crystallization from 7.09% to 14.83%. The tensile property test results showed that the film reached the maximum tensile strength of 20.55 MPa with the addition of TC-2 at 1%. The results of contact angle, water absorption, and water vapor transmission performance tests showed that TC-2 modified CaCO₃ increased the water contact angle of the composite film from 85.7° to 94.6° and decreased the water absorption from 13% to 1%. When the additional amount of TC-2 was 1%, the water vapor transmission rate of the composites was reduced by 27.99%, and the water vapor permeability coefficient was reduced by 43.19%.

Keywords: CaCO3 particles; PBAT; compatibility; titanate coupling agent.

Grants and funding

This research was funded by the Shandong Province Science and Technology Small and Medium Enterprises Innovation Capacity Enhancement Project, project Number (2022TSGC1168). This research was funded by the Zhangdian District School City Integration Development Program Project, project Number (2021JSCJ0011). This research was funded by Shandong University of Technology—Yiyuan County Industrial Technology Research Institute Science and Technology Project, project Number (202006).