Crystallization Behavior of Poly(ε-caprolactone) Grafted onto Cellulose Alkyl Esters: Effects of Copolymer Composition Miscibility

Graft copolymers of CA and CB with PCL were prepared at compositions rich in PCL. Kinetic DSC data were analyzed in terms of a folded-chain crystallization formula expanded for a binary mixing system of amorphous/crystalline polymers. The order of crystallization rates was plain PCL > CA-g-PCL (DS = 2.98) > CB-q-PCL (DS = 2.12.95) > CA-g-PCL (DS = 2.1-2.5), and the fold-surface free energy of the PCL crystals obeyed the reverse order. POM revealed a generally tardy growth of spherulites for all the graft copolymers. The slower crystallization process may be ascribed primarily to the compulsory effect of anchoring PCL chains onto the semi-rigid cellulose backbone. Intercomponent miscibility of the CA/PCL and CB/PCL pairs was also taken into consideration.