Performance of an acrylic-acid-grafted poly(3-hydroxybutyric acid)/starch bio-blend: characterization and physical properties

Abstract

Abstract-In this study, a fully biodegradable poly(3-hydroxybutyric acid) (PHB) and starch blend (PHB/starch) was prepared by means of a melt-blending method. In addition, the acrylic-acid-grafted PHB (PHB-g-AA) was studied as an alternative to PHB. It was found that the dispersion of starch in the polymer matrix and the water resistance of PHB-g-AA/starch were better those of PHB/starch, due to the formation of ester carbonyl function group via reaction between the -OH group of starch and the anhydride carbonyl group of PHB-g-AA. As the result of mechanical test, the PHB-g-AA/starch blends not only gave larger values of tensile strength than those of the PHB/starch blends, but also provided a plateau value of tensile strength when the starch content was up to 50 wt%. Furthermore, the PHB-g-AA/starch was more easily processed than the PHB/starch because the former had lower melt viscosity than the latter. Biodegradation tests of blends were also studied under the enzymatic environment, and the result showed that the mass of blends reduced by about the starch content within 6 weeks.

Poly(3-hydroxybutyrate)/multi-walled carbon nanotubes nanocomposites: preparation and characterizations

“…AA was purified before use by recrystallization from chloroform and BPO was purified by dissolving in chloroform and reprecipitating with methanol. According to the procedures described in our previous work [28], the PHB-g-AA copolymer was prepared in our laboratory and its grafting percentage was determined as being about 5.60 wt.% when BPO loading and AA loading were kept at 0.3 and 10 wt.%, respectively.…”

Structure–property relationships of reactively compatibilized PHB/EVA/starch blends

“…Whereas, the properties of PHB/starch blends are poor due to a lack of affinity between the two components (Reis et al, 2008). Although poly(vinyl acetate) (Don et al, 2010), nano-clay (Ismail & Gamal, 2010), peroxide (Avella, Errico, Rimedio, & Sadocco, 2002) and PHB-g-acrylic acid (Liao & Wu, 2007) could enhance the affinity between PHB and starch, the toughness of their blends was only improved to a certain extent.…”

Bulk composites from microfibrillated cellulose-reinforced thermoset starch made from enzymatically degraded allyl glycidyl ether-modified starch

“…The in-plane Young’s modulus was calculated according Timoshenko beam theory with the following formula: 28 where 1/ C b is the slope of the linear part of the load versus midpoint deflection curves, b the width of specimen, h the height of specimen, L the distance between the end supports, ν the Poisson’s ratio assumed to be 0.3, and β a geometrical factor assumed to be 1.2 for rectangular cross-sections. The ultimate strength was calculated from three-point bending as σ = ½ Mh/I , where the maximum moment is M = PL /4, and the second moment of area is I = bh 3 /12 and the applied load is P .…”

“…To eliminate the disadvantages such as water absorption, poor mechanical properties and processability, starch needs to be chemically modified or blended with plasticizers or other hydrophobic synthetic polymers. The polymers used to blend with starch include poly(ethylene-co-vinyl alcohol), 1 poly(3-hydroxybutyrate), 2,3 polycaprolactone, 4 polybutylene succinate adipate, 5 LDPE, 6,7 poly(lactic acid), 8,9 polyethylene-octene elastomer, 10 polybutylene succinate, konjac glucomannan 11 and lignosulfonate. 12 However, most polymers are intrinsically hydrophobic and are thermodynamically immiscible with starch leading to phase separation and often poorer mechanical properties.…”