Ph.D. Proposal by Yifeng Hong
MSE PhD Proposal – Yifeng Hong
Tuesday, January 27
3515 MRDC, Hightower Conference Room
Donggang Yao, Advisor, MSE
Meisha Shofner, MSE
Youjiang Wang, MSE
Karl Jacob, MSE
Yulin Deng, ChBE
Title: Processing of Expandable Thermoplastic/Thermoset Syntactic Foam
Abstract: While hollow glass microspheres are commonly used in syntactic foam, their abrasive and brittle properties usually result in poor processability and have adverse effects on the foam performance. Therefore, a number of attempts have been made in the industrial to replace hollow glass microspheres with polymeric foamed microspheres. Among many choices, expandable thermoplastic (ETP) microspheres filled syntactic foam has shown its high potential to become a novel class of engineering materials, especially for lightweight structural applications. However, conventional syntactic foam processing techniques usually experience difficulties such as high processing viscosity, low loading of foamed fillers, ineffective microsphere expansion, and, etc.
To address these issues, a novel microwave expansion process is proposed to produce thermoset-matrix syntactic foam containing expandable thermoplastic microspheres. The proposed process is designed to have unexpanded ETP microspheres directly foamed in uncured thermoset matrix via microwave heating. This design is expected to considerably decrease the processing difficulty and effectively expand ETP of high loadings, fulfilling the requirement of industrial-scale production of syntactic foam filled with foamed polymeric microspheres.
The proposed process design will be validated by producing epoxy-based syntactic foam with expandable polystyrene (EPS) microspheres. The engineering aspect of this study will focus on the development and optimization of the proposed microwave expansion process, the establishment of process-structure-property relation, and the extension of the process application to broader areas. Moreover, in an effort to address the fundamental aspect, the expansion process of EPS microsphere will be modeled based on continuum mechanics. The modeling work can considerably contribute to the understanding in the basics of EPS expansion process, providing important references for the simulation and optimization of similar processes.