Synthesis of polybenzoxazole foam

CHED 827

Robert P. Smart, smartr@gvsu.edu1, Kevin D. Conkel2, Brandi Murrell1, Lauren Sanford1, and Anthony F. Schultz1. (1) Department of Chemistry, Grand Valley State University, 1 Campus Drive, Allendale, MI 49401, (2) Hudsonville High School, Hudsonville, MI 49426
The lack of qualified packing systems above +250ºC is a major obstacle in fully realizing the potential of advanced high performance semiconductor materials in military and commercial systems. It is therefore necessary to produce a packaging material able to withstand higher operating temperatures and increased thermomechanical capability with the semiconductor substrate. To this end, a novel polybenzoxazole (PBO) foam material was produced via a two step process involving a polyhydroxyimide (PHI) intermediate microsphere. When heated to >300ºC, the PHI microsphere cyclizes to PBO and absorbs large amounts of heat during the cyclization reaction. Examination of the resulting foam demonstrates lightweight, non-flammable, non-toxic, shock resistant foam with thermal stability from -260ºC to +600ºC.

K. Conkel was supported by a National Science Foundation, Teacher Professional Continuum Program grant ESI-0553215. B. Murrell was supported by the Ronald E. McNair Scholars Program.