Cure in fillers presence

This section contains information on the cure response of UV-curable and thermosetting polymers in the presence of fillers. The discussion includes  

The kinetics of reaction is discussed in Section 6.10 and polymerization reactions in Section 6.7. Grafting is discussed in Section 6.8, crosslink density in Section 6.9, and bound rubber in Chapter 7. Here, UV-curable materials, epoxy resins, polyurethanes, rubbers, polyesters, and phenolic resins are discussed. 

Printing inks and wood fillers also take advantage of light curing. A1(OI I)-, is the usual choice in this application. Materials were cured by a mercury lamp and results evaluated by differential photocalorimetry and UV-visible spectroscopy. The sample weight and amount of filler were the essential variables. Addition of filler increased UV cure rate. At a low filler concentration (13.2%) the rate was only 

Densified polyurethane foam was used as a filler in rubber in an attempt to recycle this material. Small additions (up to 30%) did not much affect the cure rate but as the quantity was increased the rate of vulcanization slowed probably due to the effect of dilution and increasing viscosity. 

In interpenetrating polymer networks, chemical crosslinking and phase separation and their timing affect properties. Fumed silica, alumina, and carbon fiber were used in a network developed Ifom polyurethane and polycslcracrylalc. The presence of fillers affected many properties. Conversion rates were higher in the presence of fillers. Also, microphase separation was affected. As a result of these two changes the filled material was unrecognizable from the unfilled material. 

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