Structural Study on styrene/ε‐caprolactone block copolymers in absence and in presence of a solvent of the polystyrene block

The lamellar crystalline structure of styrene/ε‐caprolactone block copolymers (SCL) of different compositions and molecular weights is studied by X‐ray diffraction and differential scanning calorimetry. The studies were performed in the absence and in the presence of diethyl phthalate, a preferential solvent of the amorphous polystyrene block. The influence of the molecular characteristics of the copolymer and of the solvent concentration on the parameters of the lamellar structure and especially on the number of folds and on the crystallinity of the crystallizable poly(ε‐caprolactone), (PCL), chains is established. It is shown that copolymers SCL can be divided in three categories depending upon their composition.