The properties of chemical cross-linked poly(lactic acid) by bis(tert-butyl dioxy isopropyl) benzene

To improve the thermal stability and mechanical properties of poly(lactic acid) (PLA), bis(tert-butyl dioxy isopropyl) benzene (BIBP) (0–0.4 wt%) as cross-linking agent was introduced into the PLA. The PLA/BIBP x samples were characterized by Fourier transform infrared spectrometry. The gel fraction and degree of swelling of PLA/BIBP x were studied. The thermal and degradation properties of samples were also investigated by means of differential scanning calorimetry and thermogravimetric analysis; the thermal stability of the samples was improved by the addition of BIBP. The complex viscosity ( η* ), storage modulus ( G′ ), and loss modulus ( G′′ ) were increased with the increase in BIBP content from rheological measurement. The mechanical properties of the PLA/BIBP x blends and PLA/BIBP x films were tested by tensile tests, and the blends’ tensile strength was enhanced due to the cross-linking effect of BIBP. The 0.2 wt% BIBP gave the PLA/BIBP x blends the best mechanical properties, while the 0.1% BIBP made PLA/BIBP x films an optimal mechanical property. The morphology of the tear-fractured surface of the films was also studied, and PLA/BIBP0.1 film revealed more clearly layered structure than PLA.