Polymeric Systems Which Expand on Polymerization for Use in High Strength Composites.

摘要

For a number of industrial applications,it is highly desirable to have monomers that have essentially zero shrinkage or expansion on polymerization. Theoretical considerations for such reactions are discussed,including ring-opening polymerizations. Among the monomers that do indeed give essentially zero contraction or some expansion on polymerization are the spiro ortho esters,such as 2,4,6-trioxaspiro(4,4) nonane,spiro orthocarbonates,and bicyclo ketal lactones. The polymerization of the spiro orthocarbonate represents the first reported case in which a substantial amount of expansion in volume occurs during polymerization.