Study of mechanical, enzymatic degradation and antimicrobial properties of poly(butylene succinate)/pine-resin blends

Abstract

Pine resin obtained from the plant (Pinus Caribaea—Hondurensis) was melt blended with poly(butylene succinate) (PBS) in mass ratios of the pine resin up to 50 wt%. The blends were tested for mechanical strength, melting and decomposition temperature and internal and spherulitic morphology using tensile test, differential scanning calorimetry, thermogravimetric analysis, scanning electron microscopy (SEM) and polarized microscopy, respectively. Enzymatic degradation of PBS and the pine-resin blends were investigated by porcine pancreatic and candida rugosa lipases while the antimicrobial property was studied against Pseudomonas aeruginosa, Escherichia coli, Bacillus subtilis and Staphylococcus aureas using the zone inhibition method. The two components were reported to be miscible and in blends with low pine resin, the thermal stability was similar to PBS. SEM micrographs showed homogeneity in the morphology of the blends. The mechanical properties of the blends showed a decrease in Young’s modulus, but an improvement in flexibility was seen when compared to PBS. Enzymatic degradation was prominent in pine resin and blends containing pine-resin content but not with PBS. The pine resin was active against all the bacteria tested except E. coli while the blends were active against P. aeruginosa and B. subtilis.