Recycling Thermosets by High-Pressure, High-Temperature SinteringEPA Grant Number: U916106
Title: Recycling Thermosets by High-Pressure, High-Temperature Sintering
Investigators: Williams, Drew E.
Institution: University of Massachusetts - Amherst
EPA Project Officer: Michaud, Jayne
Project Period: January 1, 2003 through January 1, 2006
Project Amount: $33,556
RFA: STAR Graduate Fellowships (2003) Recipients Lists
Research Category: Academic Fellowships , Engineering and Environmental Chemistry , Fellowship - Chemistry and Materials Science
The objectives of this research project are to: (1) understand the mechanism of high-pressure, high-temperature sintering (HPHTS) and design thermosets that are more easily recycled when they reach the waste stream; and (2) employ additives (mixed with recycled thermoset powder prior to sintering) to increase the mechanical properties of the produced parts (this targets the end use of these materials, and its purpose is to increase properties such that they fit into the ranges necessary for real-world products). Thermosetting materials have long been considered impossible to remold because they do not melt or dissolve. Few technologies have been developed to recycle waste thermosets (such as polyurethanes) compared to those available for the recycling of metals, glasses, and thermoplastics (meltable polymers). Because rubbers are a subcategory of thermosetting materials, they also suffer from these limitations to recycling. Scrap rubber tires and waste polyurethanes currently represent two of the largest recycling dilemmas for our society. I propose that a reasonable solution to this problem is recycling waste thermosets by sintering at high pressures and temperatures.
HPHTS can allow parts to be produced from 100 percent recycled material (current techniques use on average less than 15 percent recycled content). To achieve a practical method for conducting this, I am working at both ends of the lifecycle of thermosetting materials. First, I am investigating several thermosetting systems to understand why some are more recyclable than others. Secondly, I am employing additives (mixed with recycled thermoset powder prior to sintering) to increase the mechanical properties of the produced parts.