Abstract
Effects of the alkyl short chain branches and of the acetoxy branches on the crystallization of ethylene-vinyl acetate copolymer (EVA) were studied by the differential scanning calorimetric method.
The following equations were obtained for the reducing effect of the short chain branches on the crystallization of EVA,
χ=0.78exp(-0.24λ)
λ=λm+1.2λa
where χ is the crystallinity of EVA, λm and λa is the number of alkyl short chain branch and acetoxy short chain branch per 100 carbons, respectively.
Therefore it is concluded that the crystallinity of EVA exponentially decreases with the increase in the contents of short chain branches, and that the reducing effect of the acetoxy branch is 1.2 times larger than that of alkyl short chain branch on the crystallization of EVA.
