![Sample our Physical Sciences journals, sign in here to start your FREE access for 14 days]({"type":"image" , "src" : "/sda/110819/TOC-Subject-Sample-2021-Physical-Sciences.jpg"})
Abstract
Maleic acid-alt-styrene (MAaS) copolymer with number-average molecular weight [Mbar] n = 2500 was used as a compatibilizer in blends of poly(ethylene oxide) (PEO) and poly(styrene) (PS). PEO with weight-average molecular weight [Mbar] w = 105 (PEO100) and two PS samples with [Mbar] w = 9 × 104 and 4 × 105, respectively (PS90 and PS400, respectively) were used. A depression of the melting temperature T m of PEO in blends containing MAaS relative to pure PEO and PEO/PS blends was observed. The melting enthalpy ΔH m for the PEO/PS blends containing MAaS was lower than those of pure PEO and PEO/PS blends without compatibilizer. The crystallization kinetics of PEO and the blends were studied by differential scanning calorimetry (DSC) at different crystallization temperatures T c. Flory-Huggins interaction parameters χ12 for the blends were estimated. Their values are in good agreement with those obtained for similar systems and suggest that the free energy of mixing ΔG mix should be negative. Polarized optical microscopy shows differences in the macroscopic homogeneity of the blends containing compatibilizer that could be attributed to a compatibilization process.
ACKNOWLEDGMENT
We express our thanks to Fondecyt, grants 8970011 and 2970010, for partial financial help. V. V. thanks to DIPUC for a doctoral fellowship. D. R. and A. O. express their thanks to Ca′tedra Presidencial en Ciencias ’95 for financial support.