Prediction studies of environment-friendly biodegradable polymeric packaging based on PLA. Influence of specimens’ thickness on the hydrolytic degradation profile

Abstract

17Application of new biodegradable polymer packaging based on polylactide (PLA), susceptible 18 to organic recycling, can help in the waste reduction in landfills. In this paper, the results of 19 the study on abiotic degradation of PLA and its blend containing 15 mol% of poly[(R,S)-3-20 hydroxybutyrate], as a model for the first step of organic recycling were presented. The 21 samples used for this study have different shapes and thicknesses: rigid films and cuboid-bars. 22Particular emphasis was placed on determining the pattern of degradation products released 23 into the medium. Originally, the results of present study revealed that the application of 24 electrospray ionization mass spectrometry supported by high performance liquid 25 2 chromatography allowed envisaging the differences in the degradation products pattern 26 released from the studied PLA-based samples differing in thickness. The significant 27 differences in degradation products pattern were predominately observed in the first steps of 28 incubation process and are caused by an autocatalytic effect, which occurs mainly during 29 degradation of the large size PLA samples. Although, the thickness of PLA-based packaging 30 changes the degradation product patterns, however this does not increase the total amounts of 31 acids released to the medium. Thus, it may be concluded that thickness should not affect 32 significantly organic recycling of the packaging. 33 34

Forensic Engineering of Advanced Polymeric Materials—Part VII: Degradation of Biopolymer Welded Joints

“…Thus, lactic acid oligomers terminated by hydroxyl and carboxyl end groups were identified as water-soluble degradation products of welded PLA 2 samples. This observation was in agreement with the results of the hydrolytic degradation of PLA after multiple extrusion as previously reported [27,[30][31][32][33][34][35][36]. Figure 9 shows the positive ESI-MS spectrum of the low molar mass compounds released from the welded PHA 3 sample to the water after 9 months of hydrolysis.…”

“…However, further heating of the PLA 2 and 2W samples above the glass transition temperature exhibit the so-called "cold crystallization" phenomenon which was not observed for the starting PLA filament (see Table 2, Figure 3). It seems that the observed phenomena in the case of samples PLA 2 and 2W, can be explained by a crystallization and/or nucleation processes that can be initiated by PLA oligomers which could form during the 3D-printing of PLA 2 sample [24][25][26][27][28].…”

“…A 10 µL volume of the sample solutions in chloroform (0.5% w/v) was injected into the system. Polystyrene standards with low dispersity were used to generate a calibration curve [27].…”

“…To investigate the impact of the welding methods used on the stability of the obtained welded joints of the PLA and PHA biopolymer samples, hydrolytic degradation tests were carried out. The progress of the degradation process was monitored by pH changes in the degradation medium, as well as the macroscopic changes of the surface of welded samples [27,33]. Figure 4 shows the changes in the pH of the degradation media versus incubation time of the PLA 1, PLA 2 and PHA 3 samples.…”

3D-Printed Polyester-Based Prototypes for Cosmetic Applications—Future Directions at the Forensic Engineering of Advanced Polymeric Materials

“…The purpose of composting is the disposal of biodegradable waste and, as a result, to produce a stabilized product that can be used or stored without further treatment. The organic recycling of biodegradable polymeric materials enables controlled biological decomposition of these polymers to safe and eco-friendly products for the environment and human life and health [21,22,23,24].…”