Morphologies and properties of plasticized starch/polyamide compatibilized blends

The aim of this review is to discuss the recent developments in thermoplastic starch blends. Starch has been considered as an excellent candidate to partially substitute synthetic polymer in packaging, agricul tural mulch and other low cost applications. Recently, the starch granules were plasticized using different plasticizers under heating and shearing, giving rise to a continues phase in the form of a viscous melt which can be processed using traditional plastic processing techniques, such as injection molding and extrusion. This kind of starch composites is called thermoplastic starch. Unfortunately, thermoplastic starch presents some drawbacks, such as low degradation temperatures, which make it difficult to process, poor mechanical properties and high water susceptibility. Much work has been carried out to overcome these drawbacks, including the combination of thermoplastic starch with other polymers, aiming at lowering the cost and enhancing the biodegradability of the final product.

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“…Only the work of Landreau et al [84] focused on TPS/PA blends. They prepared and characterized TPS/PA11 blends.…”

Section: Tps/polylactic Acid Blendsmentioning

confidence: 99%

Thermoplastic starch blends: A review of recent works

2012

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“…Natural starch exists in granular form, and it has been used as filler in plastics to increase biodegradability [2][3][4][5][6] and to lower cost as well. Since 1970s, starch has been incorporated into biopolymer matrix such as ethylene vinyl alcohol (EVOH) copolymer [7][8][9][10], PCL [11][12][13][14], PLA [15,16], PVA [17][18][19] and polyamide [20]. In the past decades many researches have been undertaken to convert starch into thermoplastic or modifying materials [21,22] in order to improve their functionality for industrial applications.…”

Section: Introductionmentioning

confidence: 99%

Effects of Modified Starch and Different Molecular Weight Polyvinyl Alcohols on Biodegradable Characteristics of Polyvinyl Alcohol/Starch Blends

2012

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The common biodegradable properties of polymer make them an excellent pair for blending, and the water solubility of polyvinyl alcohol (PVA) makes it easy to mix evenly with the starch. In this study, PVAs with different molecular weights were blended with various compositions of cross-linked starch (CLS) to explore the effects of molecular weight of PVA on the biodegradable characteristics of the PVA/starch blends. Comparing the biodegradability of all the various PVA/starch blends, a PVA was singled out from the PVA/starch blends of higher biodegradability. Further, the chosen PVA was then blended with the acid-modified starch (AMS) to systematically investigate the effects of the modified processing of starch on the biodegradable characteristics of the PVA/starch blends. Differential scanning calorimetry (DSC) analysis of PVA and PVA/starch specimens reveal that the T m values of PVA/starch specimens reduce gradually as their CLS or AMS contents increase. After the CLS is blended in PVAs of different molecular weights, the tensile strength (r f ) and elongation at break (e f ) values of (P 100 S 0 )G 20 M 1 specimen increase and simultaneously reduce, respectively, as their molecular weights of PVA increase from about 80,000 (PVA BF-17 ) to 120,000 (PVA ). The r f and e f values of the PVA/modified-starch blends decrease with an increase in the modified starch contents. The r f values of the PVA/ AMS specimens decrease with an increase in the concentrations of hydrochloric acid. Comparing the r f values of the PVA/CLS specimens with those of the PVA/AMS specimens, the r f values of the PVA/CLS specimens are better than those of the PVA/AMS specimens. On the contrary, the e f values of the PVA/AMS specimens are better than those of the PVA/CLS specimens. According to the biodegradability of all the PVA/starch blends, PVA with higher molecular weights displays higher biodegradability. The biodegradability of the PVA/modified-starch blends increase as the modified starch contents of the PVA/ modified-starch blends increase. As evidenced by the results of the biodegradability test, the biodegradability of the PVA/modified-starch blends, therein PVA is blended with 1N AMS, shows better biodegradability. The result of bio-reaction kinetics experiment can evaluate the decomposition tendency of the PVA/starch blends up to any biodegradable rate under ambient environment. Using the kinetic model of the first order reaction, it is estimated that 16.20 years and 12.47 years will be needed for the PVA BF-17 /starch blends, containing 20 and 40% of CLS respectively, to be degraded up to 70% under ambient environment. In addition, it is 1.68 years for the PVA BF-26 blends with the 40% 2N AMS under decomposition environment while it is 1.94 years for the 40% 1N AMS. Overall, the decomposition potential of PVA/AMS specimens is better than PVA/CLS specimens. Furthermore, the 1N(26P 60 AS 40 ) 100 G 20 M 1 specimen is coincidence the biodegradable material criteria of Environmental Protection Administration (EPA) of Taiwan.

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“…The morphology of a polymer blend depends on the rheological properties of components (viscosity ratio and elasticity ratio), volume fractions, and interfacial tension . To reduce the interfacial tension, it is common to add compatibilizers …”

Section: Introductionmentioning

confidence: 99%

Rheology and morphology of polyester/thermoplastic flour blends

Démé

Peuvrel‐Disdier

Vergnes

2013

J of Applied Polymer Sci

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International audienceTwo maize flours (standard and waxy grades) were plasticized in an internal mixer with a constant amount of water and two glycerol contents. The resulting thermoplastic flours (TPFs) were characterized in dynamic oscillatory shear and creep/recovery rheometry. They displayed two different behaviors: the viscoelastic behavior of a high-molecular-weight polymer for the first one and a gel-like behavior for the second one. The TPFs were then mixed with a copolyester [poly(butylene adipate-terephtalate)]. All of the blends contained the same volume fractions and were prepared with the same mixing conditions. The morphology and rheological behavior of each blend were characterized. Different morphologies, ranging from cocontinuous to nodular, were observed. In fixed mixing conditions, the blend morphology was shown to be governed by the rheological behavior of the starchy phase and the plasticizer content. The gel-like behavior of the second TPF seemed to prevent droplet coalescence; this led to a very fine dispersion. The rheological behavior of each blend appeared to be linked to both the morphology and the rheological behavior of the two phases

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Morphologies and properties of plasticized starch/polyamide compatibilized blends

Cited by 45 publications

References 24 publications

Thermoplastic starch blends: A review of recent works

Thermoplastic starch blends: A review of recent works

Effects of Modified Starch and Different Molecular Weight Polyvinyl Alcohols on Biodegradable Characteristics of Polyvinyl Alcohol/Starch Blends

Rheology and morphology of polyester/thermoplastic flour blends

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