Evaluation of hydrolytic degradation of bionanocomposites through fourier transform infrared spectroscopy

Abstract

Studies about in vitro biodegradation of polymers have grown considerably due to the wide application of biodegradable polymers in biomedical areas. The objective of this study was to prepare bionanocomposites films of PHB, PEG, and organoclays by solution intercalation, and to evaluate the morphology, structure, hydrolytic degradation through FTIR and the calculation of carbonyl content. The results showed that bionanocomposites displayed intermediated dispersion of the filler, the polymer chains were intercalated into the organoclay layers and was observed some degree of exfoliation. There was an influence of PEG and of the clay on the degradation of the polymer, this fact was observed due to the decrease in the intensity of PHB carbonyl band in the region around 1275 cm-1 , affecting the amorphous and crystalline regions of the polymer. This reduction can be associated with the increase in hydrophilicity of the polymer caused by the presence of the PEG and clay, suggesting the possibility of increasing the biodegradability of the pure polymer. In future research, there will be made characterizations to know if these materials can be used in medical devices.

Accelerated Weathering Effects on Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and PHBV/TiO2 Nanocomposites

“…The chemical structure changes of the PHBV and the PHBV/TiO 2 samples before and after the weathering test were investigated by FTIR. It can be seen in Figure 6 , the PHBV presents the characteristic bands of the neat polymer identified in previous works [ 25 , 31 , 32 , 34 , 72 , 73 , 93 ], i.e., the observed region of 3000–2800 cm −1 is assigned to the asymmetric and symmetric deformations in the methylene chains (–CH 2 –), and the bands at 1472, 1448, 1425, 1338, 1335 and 1313 cm −1 are due to the CH 2 and CH 3 asymmetric and symmetric deformations, and the C–O stretching characteristic bands are seen at 1255–1245 cm −1 for the crystalline domains, while the amorphous phase is indicated by the 1180 cm −1 peak. The strong absorbance peaks at 1713 and 1720 cm −1 are attributed to the stretching vibrations of the crystalline C=O carbonyl groups, while the absorption bands at 1730 and 1740 cm −1 are assigned to the amorphous C=O stretching.…”

“…To further confirm the extent of the degradation of each phase, the carbonyl index (ratio of the intensity heights of C=O/CH 3 ) was quantified before and after accelerated weathering. The absorbance ratios of 1720/1388 and 1713/1388 cm −1 were used to quantify the crystalline C=O of the PHBV and its nanocomposites, whereas 1730/1388 and 1740/1388 cm −1 were used to measure the amorphous carbonyl content [ 31 , 32 , 72 , 73 ]. The quantitative analysis of the carbonyl index and the ratio of crystalline/amorphous phases are presented in Table 1 .…”

“…In addition, a quantitative analysis of the ratio of the crystalline/amorphous phases was conducted. The absorbance ratios of the 1720/1388 and 1713/1388 cm −1 were used to quantify the crystalline carbonyl (C=O) content, while 1730/1388 and 1740/1388 cm −1 were used to calculate the amorphous C=O content of PHBV and its composites [ 31 , 32 , 72 , 73 ].…”

Preparation and Characterization of Bio-Based PLA/PBAT and Cinnamon Essential Oil Polymer Fibers and Life-Cycle Assessment from Hydrolytic Degradation

“…For the experimental design, the buffer was not removed. The degradation time was 4, 8, and 12 weeks at room temperature (25 ± 1 • C) and in a thermostatic bath at 37 ± 1 • C. At the end of the experiment, the pH of the degradative medium was measured, and the mass of the fibers was verified, according to the following equation [34]:…”

Effect of glassy carbon addition and photodegradation on the biodegradation in aqueous medium of poly (3‐hydroxybutyrate‐co‐3‐hydroxyvalerate)/glassy carbon green composites

“…Probably, the process of macromolecular scission was accompanied by the rearrangement of polymeric chains in organized structures (crystallites), increasing the X c value of the material (as observed in the DSC results) and explaining the increase in the intensity of the band located at 1722 cm −1 , which is related to the crystalline phase. 50 The samples exposed to the biodegradation process in the C.2 condition presented a reduction in the intensity of all the absorption bands verified in the FT-IR curves. For example, there is a decrease in the intensity of the absorption band at 1182 cm −1 , which may be attributed to the consumption of the PHBV amorphous phase by microorganisms.…”