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Journal ArticleDOI

Preparation and characterization of thermoplastic starch/zein blends

TL;DR: The use of zein in thermoplastic starch compositions causes a decrease in the water sensitivity of these materials and lower its melt viscosity during processing making zein a suitable and very promising component in TPS compositions as mentioned in this paper.
Abstract: Blends of starch and zein plasticized with glycerol were prepared by melting processing in an intensive batch mixer connected to a torque rheometer at 160 °C. The resulting mixtures were compression molded and then characterized by scanning electron microscopy, differential scanning calorimetry, wide-angle X ray diffraction and water-absorption experiments. The blends were immiscible, showing two distinct phases of starch and zein. The water uptake at equilibrium and its diffusion coefficient were determined. The water uptake at equilibrium decreased with increasing zein content. The diffusion coefficient fell sharply on addition of 20% zein and remained constant as zein content was increased. No appreciable effect of zein on starch crystallization was observed by X ray diffraction. The use of zein in thermoplastic starch compositions causes a decrease in the water sensitivity of these materials and lower its melt viscosity during processing making zein a suitable and very promising component in TPS compositions.

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Citations
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Book ChapterDOI
01 Jan 2017
TL;DR: Diverse processing methods as well as characteristics and properties of these functionalized materials, particularly, actual biodegradability/compostability and food contact compliance of these novel starch-based materials are included in this section.
Abstract: Structural modifications of native starches could be considered as an alternative to obtain derivatives with enhanced properties, relevant in the materials field. In this chapter, the use of several modified starches from different botanical origin for this purpose is well discussed. Thus, diverse processing methods as well as characteristics and properties of these functionalized materials, are described. Particularly, actual biodegradability/compostability and food contact compliance of these novel starch-based materials are also included in this section.

19 citations

Journal ArticleDOI
TL;DR: In this article, the effect of zeolite 5A on compatibility between PE and TPS, as well as morphological, thermal, and tensile properties of PE/TPS/Z composites was investigated.
Abstract: Polymer composites consisting of linear low-density polyethylene (LLDPE), thermoplastic starch (TPS), and zeolite 5A (Z), with a constant PE to TPS weight ratio of 70 : 30 and zeolite 5A contents of 1–5 wt % were prepared in the forms of pellets and films by using a co-rotating intermeshing twin-screw extruder and a blown film extrusion line, respectively. The objective of this work was to investigate the effect of zeolite 5A on compatibility between PE and TPS, as well as morphological, thermal, and tensile properties of PE/TPS/Z composites. The presence of zeolite 5A increased the miscibility and tensile properties of the PE/TPS blend. Tensile properties of the blend considerably improved after compounding with zeolite 5A, as the tensile strength, modulus, and elongation at break increased significantly (P ≤ 0.05) by up to ∼ 60, 30, and 70%, respectively. Increasing the zeolite 5A content from 1–5 wt % significantly increased (P ≤ 0.05) the tensile strength, modulus, and elongation at break of PE/TPS/Z composites from ∼ 12 to 16 MPa, 133 to 154 MPa, and 305 to 390%, respectively. However, the addition of zeolite 5A slightly decreased the thermal stability of the PE/TPS blend by ∼ 5–15°C. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

19 citations

Journal ArticleDOI
TL;DR: In this article, different strategies to produce thermoplastic materials using starch and zein were studied, aiming to investigate their effect on the compatibility of starch and zerotime.
Abstract: Different strategies to produce thermoplastic materials using starch and zein were studied, aiming to investigate their effect on the compatibility of starch and zein. Research strategies comprised the use of two different plasticizers for starch, two different compatibilizing agents, and two blending procedures. The plasticizers were mixtures of sorbitol and glycerol (SG) or urea and formamide (UF). UF and maleated starch (MS) were used as compatibilizing agents. The blending procedures included: (1) thermoextruding starch and zein as premixed powder materials (TP[Mix]) and (2) coextruding the biopolymers previously thermoplasticized with suitable plasticizers. As observed by the tensile tests, scanning electronic microscopy, and dynamic mechanical analysis, segregation of phases occurred at different extents in all the starch–zein blends. Materials made with MS through the TP[Mix] procedure presented the most severe phases segregation, while the materials made with UF showed higher compatibility between starch and zein. Fourier Transform Infrared Spectroscopy (FTIR) suggests that increased zein content leads to a lower molecular order, which was ascribed to diminished molecular entanglement. Thermogravimetric analysis and FTIR analysis showed that the chemical interaction between starch and zein occurred more extensively in slabs made with UF than those made with MS. In addition, foamability was evaluated for the selected materials using supercritical CO2. Neat thermoplasticized starch plasticized with UF and themoplasticized zein with polyethylene-glycol 400 showed good suitability to be foamed, producing foams with porosities above 85 %. Starch plasticized with SG and starch–zein blends yielded compact structures with low porosity values after foaming.

18 citations

Journal ArticleDOI
TL;DR: In this article, the development and characterization of thermoplastic corn starch-based composites, reinforced with barley straw particles made by thermal compression, is presented. But the study materials were prepared by using three particle concentrations (5, 10, and 15 %), while the matrix (0 %) was used as a reference.
Abstract: Currently, greater environmental awareness promotes research and development advances in biodegradable materials; they represent an alternative that decreases the environmental impact caused by traditional synthetic plastics. This study consists of the development and characterization of thermoplastic corn starch-based composites, reinforced with barley straw particles made by thermal compression. The study materials were prepared by using three particle concentrations (5, 10, and 15 %), while the matrix (0 %) was used as a reference. A mechanical evaluation of all samples was carried out, as well as that of their water absorption properties. They were also characterized by scanning electron microscopy (SEM), infrared spectroscopy (FTIR), X-ray diffraction (XRD), and flammability tests. The inclusion of straw in the thermoplastic matrix increased water absorption and quickened carbon formation, although it also increased its tensile strength (7 MPa) and the Young’s modulus of activity (MOE) (420 MPa) with a 15 % reinforcement. The FTIR analysis highlights the presence of a carbonyl signal (1720 cm-1) caused by a thermal breakdown (caramelization) linked to barley particles. Moreover, X-ray diffraction demonstrated a VA-type crystallinity pattern (anhydrous) within the biocomposites and an increase of the crystallinity index, through incorporating barley particles in the thermoplastic corn starch-based matrix.

18 citations

Journal ArticleDOI
Bin Guo1, Li-Jian Wang1, Peng Yin1, Bengang Li1, Panxin Li 
TL;DR: The ultra-high molecular weight polyethylene (UHMWPE) fibers were first used to reinforce thermoplastic starch (TPS) by a twin screw extruder as discussed by the authors.
Abstract: The ultra-high molecular weight polyethylene (UHMWPE) fibers, as the fibrous morphology of polyethylene (PE), were first used to reinforce thermoplastic starch (TPS) by a twin screw extruder. The i...

16 citations


Cites methods from "Preparation and characterization of..."

  • ...The torque rheological test simulates the processing conditions in an extruder and provides the basis for developing quantitative levels of processability as a function of mixing time.(34) Typically, a very sharp peak of torque can be detected during processing that occurs at the loading stage....

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References
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Book
01 Jan 1956
TL;DR: Though it incorporates much new material, this new edition preserves the general character of the book in providing a collection of solutions of the equations of diffusion and describing how these solutions may be obtained.
Abstract: Though it incorporates much new material, this new edition preserves the general character of the book in providing a collection of solutions of the equations of diffusion and describing how these solutions may be obtained

20,495 citations

Journal ArticleDOI
TL;DR: The combination of bio-fibers such as kenaf, hemp, flax, jute, henequen, pineapple leaf fiber, and sisal with polymer matrices from both nonrenewable and renewable resources to produce composite materials that are competitive with synthetic composites requires special attention as discussed by the authors.
Abstract: Sustainability, industrial ecology, eco-efficiency, and green chemistry are guiding the development of the next generation of materials, products, and processes. Biodegradable plastics and bio-based polymer products based on annually renewable agricultural and biomass feedstock can form the basis for a portfolio of sustainable, eco-efficient products that can compete and capture markets currently dominated by products based exclusively on petroleum feedstock. Natural/Biofiber composites (Bio-Composites) are emerging as a viable alternative to glass fiber reinforced composites especially in automotive and building product applications. The combination of biofibers such as kenaf, hemp, flax, jute, henequen, pineapple leaf fiber, and sisal with polymer matrices from both nonrenewable and renewable resources to produce composite materials that are competitive with synthetic composites requires special attention, i.e., biofiber–matrix interface and novel processing. Natural fiber–reinforced polypropylene composites have attained commercial attraction in automotive industries. Natural fiber—polypropylene or natural fiber—polyester composites are not sufficiently eco-friendly because of the petroleum-based source and the nonbiodegradable nature of the polymer matrix. Using natural fibers with polymers based on renewable resources will allow many environmental issues to be solved. By embedding biofibers with renewable resource–based biopolymers such as cellulosic plastics; polylactides; starch plastics; polyhydroxyalkanoates (bacterial polyesters); and soy-based plastics, the so-called green bio-composites are continuously being developed.

1,921 citations

Journal ArticleDOI
TL;DR: In this paper, the composites were conditioned at various moisture contents in order to evaluate the effect of amylopectin on the composite structure, and the resulting films were characterized using scanning electron microscopy, differential scanning calorimetry, water absorption experiments, and wide-angle X-ray scattering.
Abstract: Nanocomposite materials were obtained using glycerol plasticized starch as the matrix and a colloidal suspension of cellulose whiskers as the reinforcing phase. The cellulose whiskers, prepared from tunicin, consisted of slender parallelepiped rods with a high aspect ratio. After mixing the raw materials and gelatinization of starch, the resulting suspension was cast and evaporated under vacuum. The composites were conditioned at various moisture contents in order to evaluate the effect of this parameter on the composite structure. The resulting films were characterized using scanning electron microscopy, differential scanning calorimetry, water absorption experiments, and wide-angle X-ray scattering. An accumulation of plasticizer in the cellulose/amylopectin interfacial zones was evidenced. The specific behavior of amylopectin chains located near the interface in the presence of cellulose probably led to a transcrystallization phenomenon of amylopectin on cellulose whiskers surface.

622 citations

Journal ArticleDOI
TL;DR: In this article, a review of the early literature on zein is presented, which reexamines the old literature and reconciles it with new zein research to illustrate some of the unique properties of and opportunities for zein.
Abstract: Corn is the largest and most important agricultural commodity in America. Zein, one of the components in corn, has long been investigated for uses other than food and feed. Zein is a unique and complex material, and it is one of the few cereal proteins extracted in a relatively pure form. Today, because of environmental concerns, interest in zein utilization is again growing. Some of the more important research on zein is more than 50 years old. Most of this work has been either forgotten, lost, or difficult to locate. Much of this work was done at the USDA laboratory in Peoria, IL. Since most early zein literature is still easily accessible at that laboratory, this review on zein has been prepared making use of this old literature. This review reexamines the old literature and reconciles it with new zein research to illustrate some of the unique properties of and opportunities for zein.

461 citations

Trending Questions (1)
How does zein and phosphorylated starch form bonds?

The provided paper does not mention anything about the formation of bonds between zein and phosphorylated starch.