Biochar Reinforced Polyvinyl Alcohol /Corn Starch Biocomposites

Abstract

The utilization of biochar in polymer composites can be considered as a sustainable approach that provide valorization of a waste to a value-added material and at the same time diminish biowaste in a smart way. This study is focused on the evaluation of biochar as a filler in polyvinyl alcohol /corn starch composites. The composites were prepared via solution mixing and casting method using citric acid as a plasticizer and glutaraldehyde as a cross-linker. Distribution of biochar in the PVA/starch matrix was evaluated by optical microscopy. The structural features of composites were characterized using FTIR spectroscopy. Effects of biochar loading ratio (0-12 wt%) on the thermal stability of the PVA/starch blends were determined by differential scanning calorimetry and thermogravimetric analyses. The decomposition temperatures of the PVA/starch/biochar composites decreased in comparison to PVA/starch composites.

Physical Properties of Thermoplastic Cornstarch/Hibiscus sabdariffa Fiber Obtained by Evaporation Casting

“…The composites with fiber present slightly a lower resistance to mass loss, with the degradation onset temperature ( T onset ) of 261 °C shown for starch. [ 33 ] For the composites with HS fibers, a T onset displacement toward low temperatures was observed, together with the progressive loss of mass, demonstrating the effect of biodegradation acquired with the progressive addition of the fibers. The SH10 sample was the one that presented the greater loss of mass and greater displacement of T onset relative to the reference sample (starch).…”

“…Starch consists of a large number of glucose units connected by glycosidic bonds; the fundamental formula of this polymer is (C 6 H 10 O 5 ) n . [ 33 ] Likewise, the HS fiber is mainly composed of cellulose, a molecule derived from d ‐glucose units, which condense through β(1→4)‐glycosidic bonds.…”

“…These main signals have already been recognized before by other authors. [ 7,33 ] No structural and conformational modifications were detected in the composites due to the effects of the fiber composition ratio.…”

“…[7,32] The FTIR spectra of the composites are illustrated in Figure 3, where the principal functional groups in their structures are highlighted. Starch consists of a large number of glucose units connected by glycosidic bonds; the fundamental formula of this polymer is (C 6 H 10 O 5 )n. [33] Likewise, the HS fiber is mainly composed of cellulose, a molecule derived from dglucose units, which condense through 𝛽(1→4)-glycosidic bonds.…”

Electrical and Mechanical Properties of Sugarcane Bagasse Pyrolyzed Biochar Reinforced Polyvinyl Alcohol Biocomposite Films

“…The decrease in peak intensity at approximately 2930 cm −1 , 1400 cm −1 , and 1080 cm −1 corresponding to -CH 2 -asymmetric stretching, -CH 2 -bending stretching, and -C-O-H stretching vibration indicated that biochar functional groups developed during pyrolysis could strongly interact with these groups. This observation indicated that the biochar could form a chemical bond with the PVA matrix during the biocomposite film formation, which indicated the good compatibility between biochar and PVA [3,30,38]. The absence of intensity of peak for -OH indicated lower moisture content in the biochar than that in the PVA and hydrogen bond formation with -OH in the PVA and the oxygen containing group in the biochar.…”