Effect of the Short Chain Branch Length on Crystallization and Melting Behavior of Ethylene/α-olefin Copolymers

Three different ethylene/α-olefin copolymers with 1-butene, 1-hexene and 1-octene as comonomers were slowly fractionated based on crystallizability using preparative temperature rising elution fractionation (P-TREF) method. The homogenous short chain branch (SCB) content fractions were subsequently tested by differential scanning calorimetry (DSC). By comparison of the same SCB content fractions with different SCB lengths from 2 (in 1-butene comonomer) to 6 carbons (in 1-octene comonomer), valuable results were obtained. Crystallization and melting behavior were deeply analyzed. Interesting correlations between melting temperature (Tm) as well as crystallization temperature (Tc) and SCB content were presented at each SCB length. To the best of our knowledge, for the first time a mathematical correlation between Tm as a function of both SCB content and SCB length was presented

کلیدواژه ها:

Ethylene/α-olefin copolymer ، short chain branch length ، crystallization ، melting ، preparative temperature rising elution fractionation (P-TREF)