Observations of the effects of different chemical blowing agents on the degradation of poly(lactic acid) foams in simulated soil

Abstract

This work examined the influence of different chemical blowing agents (CBA), one endothermic and one exothermic, at the same concentration (2% by mass), on poly(acid lactic), PLA foams. The CBA was incorporated into the PLA in a single-screw extruder, and the foams were expanded by heating in an electric oven under free pressure conditions. Foam degradation in a simulated soil was performed according to the ASTM G160-03 standard. Changes in the physical-chemical, morphological and mechanical properties were used to evaluate the degradation. The results indicated that the different chemical blowing agents led to different mechanical and morphological properties for the foams, which resulted from the nature and decomposition rate of the blowing agents. Cells in the foams accelerated the degradation since they facilitated the infiltration of water toward the interior of the polymer and triggered the degradation process by hydrolysis.

Thermal and Mechanical Properties of Silica–Lignin/Polylactide Composites Subjected to Biodegradation

“…However, samples after biodegradation were characterized with slightly higher values of X c . Similar tendency was observed by Zimmermann et al [28]. According to literature this is probably a result of biodegradation process that in the first stage takes place in amorphous regions and thus enhances the crystallinity degree [29].…”

Effect of Cellulosic Waste Derived Filler on the Biodegradation and Thermal Properties of HDPE and PLA Composites

“…Paper consists mainly of cellulose fibers but also contains hemicellulose and lignin [48]. Cellulose is characterized by a) peak at 1425 cm −1 , known as the crystalline band, caused by the vibrations of the aromatic skeleton combined with the bending of the C-H (a lowering of its intensity reflects the decrease in the degree of crystallinity of samples), b) peak at 1032 cm −1 , associated both with the symmetrical CO stretching of the cellulose and with the CO deformation of the primary alcohols in the lignin, c) peaks between 3400-3300 cm −1 and 1593 cm −1 attributed to the stretching and bending, respectively, of OH groups of cellulose [48][49][50]. This modification, together with the shift of peak at 1316 cm −1 towards higher values, denotes the development of new inter-and intramolecular hydrogen bonds.…”

Foamability and Special Applications of Microcellular Thermoplastic Polymers: A Review on Recent Advances and Future Direction

“…Zimmermann et al. [ 300 ] conducted studies on the effect of different CBAs on the degradation of PLA foams in simulated soil. The CBA was compounded with PLA in a single‐screw extruder at low temperatures to avoid decomposition of CBA.…”