Starch/zirconium phosphate composite films: Hydration, thermal stability, and mechanical properties

Abstract

Composite films of plasticized potato starch filled with 1, 4, and 6 wt% zirconium phosphate (ZrP) particles have been prepared by casting mixtures of gelatinized starch, a gel of partially exfoliated ZrP in water, and glycerol. The XRD patterns of the composite films reveal the formation of glycerol intercalated ZrP for the highest filler loadings (4 and 6 wt%) while suggest partial filler exfoliation for the composite with 1 wt% ZrP, in agreement with TEM analysis. The presence of the filler improves the thermal resistance of the starch, both at low and, particularly, at high temperature. The composites also exhibit a significant enhancement in the Young's modulus (from ∼700 MPa for neat starch up to ∼1600 MPa for 6 wt% filler loading) and in the yield stress (from ∼17 to ∼38 MPa). The increase in stiffness is concomitant with a water uptake reduction, which is maximum at 100% relative humidity.

Preparation of thermoplastic starch/treated bagasse fiber composites

“…Figure 4 presents the TGA thermograms of the TPS and the TPS/treated bagasse fiber composites with 10 and 20 wt% of treated bagasse fiber. There were two steps of weight loss in all samples the first, from 50 to 110°C, that was assigned to water evaporation [20,21]. However, the percentages of the weight loss in the TPS and the composites at this step were significantly different.…”

A brief review on α-zirconium phosphate intercalation compounds and nano-composites

“…The presence of -ZrPO 3 decreased the moisture uptake of the nano-composite films, resulting from the hydrogen bonding formed between -ZrPO 3 and starch molecules. Composite films of potato starch and -ZrPO 3 were also prepared by using glycerol as plasticizer agent and gels of -ZrPO 3 in water as a source of high aspect ratio filler particles [55]. In this work, the presence of the filler improves the thermal resistance of the starch at both low and high temperatures.…”

“…Accordingly, several experimental methods have been developed to synthesize polymer/-ZrPO 3 inorganic nano-composites, including exfoliation-adsorption, in-situ intercalative polymerization, melt intercalation and template synthesis [37][38][39][40]. There have been several experimental investigations on polymer/-ZrPO 3 nano-composites including poly (ethylene terephthalate)(PET)/-ZrPO 3 [41], epoxy/-ZrPO 3 [42][43][44][45], polyacrylamide (PAM)/-ZrPO 3 [46,47], poly(vinyl alcohol) (PVA)/-ZrPO 3 [48][49][50][51][52][53], and starch/-ZrPO 3 [54,55]. These nano-composites will be reviewed in detail in the following paragraphs and the combustion and mechanical properties of some nano-composites are listed in Tables 1 and 2.…”

Surface modification of layered zirconium phosphates: a novel pathway to multifunctional materials

“…Pica and co-workers have shown the organic modification of α-ZrP with aminoalcohols and phosphonic acids for the use as fillers in starch. 46,47 In these cases the organic molecule interacts with the surface and the interlayer to produce an organically modified material.…”