A Study of the Thermolysis Behaviour of Pmma in Polymer/SiO2-PbO-B2O3 Glass Powder Mixtures

Abstract

ABSTRACTThe binder burn-out behavior in PMMA/glass powder composites was studied as a function of glass composition in the PbO-SiO2-B203 system. The PbO content was varied to obtain glasses having optical basicities in the range of 0.62-0.81. TGA measurements on PMMA/glass composites show that the main decomposition end temperatures of PMMA increase with decreasing PbO content, and therefore, decreasing optical basicity. This indicates that PMMA interacts strongly with more acidic surfaces. The effect of the milling fluid was also studied. Milling in toluene does not significantly alter the behavior. Milling in water of a PbO-rich glass leads to significant leaching of lead. During drying, the leached lead deposits on the glass particle surfaces and drastically alters the thermal behaviour of the glass powder and PMMA/glass composites.