Preparation of Esterified Styrene-maleic Anhydride Copolymer and Investigation of Physical and Mechanical
Properties of Its Blends with LLDPE
Linear low density polyethylene (LLDPE) was blended with esterified styrene-maleic anhydride (ESMA) and its physical and mechanical properties were studied. Styrene-maleic anhydride (SMA) copolymer was synthesized by precipitation reaction. Then, SMA was esterified by 1-decanol in methylethyl ketone solvent. From the FTIR spectrum of ESMA it is evident that the corresponding peaks of anhydride groups have disappeared and on the other hand, the acidic and ester groups are observed. Thermal behavior of SMA and ESMA was studied by DSC and TGA. In DSC micrograph, a single peak at 143oC was observed for SMA, while for ESMA a broad peak appeared, showing the different thermal characteristics of two samples. TGA micrograph showed that SMA was degraded in one stage, while, two stages of weight loss were observed for ESMA. LLDPE was blended with different amounts of ESMA in an internal mixer. Films of various blends were produced by pressure molding. Tensile modulus of the blends shows improvements by increasing the ESMA fractions of the system. On the other hand the tensile strength and elongation-at-break for various blends decreased with increasing ESMA content. Contact angle measurement and incubation in a buffer solution (pH=8) showed that hydrophilicity and water solubility were increased along with ESMA content of the blends.