Title

New Wood-Polymer Composites Containing Ethyl Alpha-(hydroxymethyl)acrylates

Date of Award

1992

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Polymers and High Performance Materials

First Advisor

Lon J. Mathias

Advisor Department

Polymers and High Performance Materials

Abstract

Wood-polymer composites (WPCs) from Southern pine and balsa wood have been prepared by impregnating whole wood samples with ethyl $\alpha$-(hydroxymethyl)acrylate (EHMA) alone and with comonomers which included vinyl azlactone, styrene, and methyl methacrylate plus free radical initiator. The monomers were polymerized in situ using thermal activation or a combination of thermal and microwave energy. The WPCs were tested for increased dimensional stability (water soaking swell resistance) and mechanical properties over untreated wood. Increased dimensional stability was observed for all WPCs containing copolymers of EHMA with a maximum antiswell efficiency (ASE) of 85% being achieved by impregnation with EHMA alone. Improvements of 91% in toughness and 85% in modulus were attained by impregnating with comonomers of EHMA and styrene. Solid state $\sp{13}$C NMR verified complete conversion of monomers with difference spectra showing strong interaction between the wood and polymer components. Scanning electron microscopy confirmed good polymer-cell wall interaction and energy dispersive x-ray analysis verified the presence of polymer within the cell walls.