Basswood-MMA composite

Figure 5. Time to exothermic peak (tp) vs. percent vazo catalyst added to basswood-MMA composite. Exothermic peak temperature and percent monomer conversion are shown on the curve.(Reproduced with permiS sion from Ref. 31. Copyright 1972, Springer-Verlag.)...

Table IQ. Effect of TMPTMA Cross-linker on Polymerization of Basswood-MMA Composite...

Figure 8 shows a plot of the time (tp) to the exothermic peak as a function of the percentage of TMPTMA added to the basswood-MMA composite. At TMPTMA concentrations above 10%, the time to the exothermic peak remains essentially constant. The increase in the rate of reaction, i.e., the decrease in the time to the exothermic peak, primarily is due to the formation of the three-dimensional gel structure because the rate of reaction becomes diffusion controlled as the viscosity increases. Thus, the rate of termination decreases and the radical becomes effectively fixed in space and only adds more monomer molecules. The probability of encountering another free radical and terminating the chain growth is small. 

Figure 15 illustrates the load-deflection curves that were obtained from the experimental data. The Heilman-Gulf epoxy and the f rf-butylstyrene monomers were an improvement over the MMA. When the t rf-butylstyrene was diluted with 50% methanol the wood-polymer composite contained half of the maximum polymer loading, and the load-deflection data were the same as the untreated basswood. To obtain the maximum improvement in physical properties the wood must be fully loaded with polymer. In another study... 

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