Modification of LLDPE using esterified styrene maleic anhydride copolymer: Study of its properties and environmental degradability

Abstract

Linear low-density polyethylene (LLDPE) was blended with decanol-esterified styrene maleic anhydride copolymer (MDESMA) with an aim to enhance the environmental degradability of polyethylenes. Styrene-maleic anhydride copolymer (SMA) was synthesized by precipitation polymerization, using benzoyl peroxide (BPO) as initiator. SMA was esterified with a long-chain monoalcohol, n-decanol, using methyl ethyl ketone (MEK) as solvent at 80°C to obtain monoesterified styrene-maleic anhydride (MDESMA). Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimeter (DSC), and thermogravimetric analysis (TGA) were performed to characterize SMA and MDESMA. IR spectra of MDESMA showed a decrease in intensity of peak responsible for carbonyl absorption of a five-membered ring anhydride group along with broadening of carboxyl O-H stretching peak. TGA showed two-stage degradation for SMA and MDESMA. LL-DPE was blended with MDESMA in single-screw extruder and blends were characterized thermally by DSC and TGA. A single endothermic melting peak of LLDPE/MDESMA blend was observed. Films of the blends, formed by compression molding, showed an increase in modulus of elasticity but a decrease in elongation at break with increasing concentration of MDESMA. LLDPE/MDESMA blend compositions when kept in phosphate/citric acid buffer solution (pH ϳ 8) showed initial weight gain because of water absorption and subsequently loss in weight due to dissolution of soluble component of blends. Film samples of blends kept for soil burial also showed similar behavior. Contact-angle measurement of film samples of the blends showed an increase in value on soil burial, indicating degradation/dissolution of MDESMA

In vitro amoebicidal activity of poly(maleic anhydride-co-vinyl acetate) copolymer on Acanthamoeba spp. trophozoites and cysts

“…MAVA copolymer (Fig. 1) had anhydride units at 1880 cm -1 , and 1804 cm -1 as expected, indicating symmetric and asymmetric C=O stretching vibrations, respectively [28][29][30]. Characteristic C-O stretching vibrations at 1242 cm -1 and 1012 cm -1 and a CH3 group of VA stretching vibration at 1395 cm -1 were observed [31].…”

Design, synthesis, structural characterization and cell cytotoxicity of a new derivative poly(maleic anhydride-co-vinyl acetate)/miltefosine polymer/drug conjugate

“…Frequency vibrations of C-O-C bond on anhydride ring were found at 1025.21 cm -1 and 934.96 cm -1 [28]. Another carbonyl (C=O) symmetric and asymmetric stretches of VA was at 1715.67 cm -1 [29], CH3 and CH2 belong to VA stretching frequencies at 1373.80 cm -1 and 1430.38 cm -1 , respectively [30,31], characteristic acetyl (-COCH3) group stretching frequencies of VA were at 1095.30 cm -1 [26], C-C vibration at 603.84 cm -1 , C-O-C stretching at 1214.91 cm -1 , and C-H group stretching vibration at 2943.19 cm -1 [32,33].…”

“…Characteristic -CH stretching vibration of VA along with the copolymer backbone stretching vibrations at 1403 cm -1 [35], CO-O-C ester groups or C-C of VA located at 1226.97 cm -1 , and a CH2 deformation at 1585 cm -1 [36]. Peak observed at 1755 cm -1 could be assigned to -COOH carboxylic acid units [32]. 1394.31 cm -1 could be associated with MF because the same peak was also observed on pure MF spectrum.…”

Synthesis, characterization and antiproliferative activities of novel modified poly (maleic anhydride-co-vinyl acetate)/cytosine ?-Darabinofuranoside hydrochloride conjugate

“…MAVA copolymer (Fig. 1a) had anhydride units at 1880 and 1804 cm -1 , indicating symmetric and asymmetric C=O stretching vibrations of MA unit, respectively (22,26,27). C-O-C stretching vibrations, from MA ring, were observed at the 936 cm -1 (28).…”