The Influence of Hollow Polysiloxane Microspheres for Syntactic Foam Energy Absorption
Sofia Gomez, University of Texas at El Paso
Polymer hollow microspheres with superior elastic properties, high thermal stability, and energy absorption capabilities are necessary for many applications, such as in the civil, medical, and defense industries, where shock and vibration must be minimized. To produce hollow polymer microspheres, core-shell composites were developed, and the polystyrene core was thermally removed to yield a polysiloxane shell, resulting in hollow polysiloxane microspheres (HPMs). A syntactic foam was formed by embedding HPMs in a polydimethylsiloxane (PDMS) matrix. A cyclic uniaxial compression test was conducted in accordance with ASTM 575 to measure the mechanical energy absorption characteristic of polymer syntactic foams. Engineered compression responses were demonstrated by fabricating and testing syntactic foams with different porosities, between 50 volume percent and 70 volume percent. We have observed that HPM contributes to the syntactic foam's energy absorption through scanning electron microscopy (SEM). Additionally, Fourier Transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) confirmed the need for a comprehensive study to better understand the effects of varying HPM synthesis parameters as well as the manufacturing process for the syntactic foam. According to our findings, synthesized HPM syntactic foams with 70 percent porosity can be used over bulk PDMS to increase compressive modulus and toughness by 20 percent. Using fabricated HPM-PDMS syntactic foams with 50 volume percent porosity also resulted in an increase of 540 percent in energy absorption.
Abstract Author(s): Sofia G. Gomez, Andrea Irigoyen, Stephanie Gonzalez, Kevin Estala-Rodriguez, Evgeny Shafirovich, Md Sahid Hassan, Saqlain Zaman, Yirong Lin