Models and Theories Regarding the Brittle-Ductile Transition of Rubber-Toughened Thermoplastics and Their Application in the Design of High-Impact Polymer Composites with Balanced Toughness and Rigidity
Yunbao Gao, Zonglin Jiang, Jianing Zhang, Haiying Tan, Jing Jin, Wei Jiang
Abstract
Toughness and stiffness are two parameters that determine whether a polymer can be used as an engineering material. Therefore, polymer toughening and stiffening have been continuously attractive and important topics for both polymer science and engineering. The brittle-ductile transition (BDT) of a polymer plays an important and special role in high-impact polymer preparation and its application because the critical BDT point is the reference point for designing a ductile polymer and the limit point for its application as a ductile material. Moreover, the BDT point also determines the balance between the toughness and rigidity of toughened polymers. In this review, factors such as morphology, properties of the toughening particles and matrix polymer, temperature, and deformation speed that can affect the BDT of particle-toughened thermoplastics are first summarized. Subsequently, the model and theory concerning the relationships among these factors at the critical BDT point are systematically introduced in detail. Finally, recent progress in designing and preparing high-impact polymer composites with balanced toughness and rigidity on the basis of the model and theory of the brittle-ductile transition is introduced and discussed.