Eco-composite from poly(lactic acid) and bamboo fiber

Abstract

Bamboo fiber-filled poly(lactic acid) (PLA) eco-composites were prepared by mechano-chemical compositing with bamboo fiber (BF)-esterified maleic anhydride (MA) (BF-e-MA) in the presence of dicumyl peroxide as a radical initiator. Tensile properties of the composites were improved by adding BF-e-MA and the dicumyl peroxide. A sufficient effect of the addition on the tensile property of the composites was observed even in the presence of the dicumyl peroxide of 0.25%. However, the composites with BF-e-MA usually showed a higher activation energy for thermal flow, indicating that their flow became more difficult, because molecular motions were rather suppressed by cross-linking of BF-e-MA with the PLA matrix resin. The crystallization temperature of PLA became higher by the addition of BF and BF-e-MA in non-isothermal crystallization. It was confirmed by scanning electron microscope and polarizing microscope observation that interfacial properties between BF and PLA were improved after the addition of BF-e-MA. A diffusion coefficient (D) of water in the PLA/BF composites with BF-e-MA was smaller than that in the composites without BF-e-MA. An equilibrium water-sorption amount (M∞) was higher in the order of composites without BF-e-MA>composites with BF-e-MA>pure PLA.

Characterization of hydrolytic degradation of polylactic acid/rice hulls composites in water at different temperatures

“…As expected, the diffusion of water into the composites increased with the increase of rice hulls content. This agrees with the previous studies [5,18] by demonstrating the role of rice hulls as hydrophilic fillers in the composite.…”

“…The diffusion of water into these products was higher during the first periods and decreased gradually until they were saturated suggesting a classical Fickian diffusion phenomenon. A mixed diffusion behavior has been reported previously in other PLA products [5,18,2]. However, it is shown that most of the PLA products that were immersed at 69°C ( Figure 1c) did not reveal consistent saturations and therefore failed to exhibit Fickian diffusion phenomenon.…”

“…Absorption of water into the polymer composite is controlled by diffusion. If the diffusion follows Fickian behavior, an increase in weight can be described in terms of the diffusion coefficient, D, and the maximum moisture content, M m as shown by Equation (1) [5,18]. (1) where M t is the degree of water-sorption at time t; M m is the water-sorption amount at equilibrium sorption time; h is the thickness of the specimen; and t is the water-sorption time.…”

“…There has been a growing interest in the development of environmentally benign composites based on biodegradable poly(lactic acid) (PLA) polymer and various lignocellulosic materials such as kenaf [1,2], flax [3], hemp [4], bamboo [5,6], wood fibers [7], and reed fibers [8]. Addition of lignocellulosic materials in PLA is intended to improve the properties of this polymer without compromising its biodegradability.…”

Sustainable biocomposites based on autohydrolysis of lignocellulosic substrates

“…The latest trend in this field is to develop new materials which are based on 100% renewable resources [18]. In this way, "green bio-composites" or "eco-composites" [19,20], obtained by embedding biofibers with renewable resource-based biodegradable polymers, open the way to the next generation of sustainable, environmentally friendly, eco-efficient materials, products, and processes [21]. This kind of composites have been cited as one of the most keenly required materials in the 21 st century [20].…”