PROPERTIES OF BIODEGRADABLE THERMOPLASTIC STARCH

Thermoplastic starch is a kind of modified starch produced by mixing starch with additives and processing the mixture in an extruder. The mechanical properties, including tensile strength and elongation at break, biodegradability and rheological properties were studied. Glycerol and urea, to some extent, can both decrease the tensile strength and increase percentage elongation at break, because the former acts as a plasticizer and the latter can break down interactions among starch macromolecules. Thermoplastic starch shows thermoplasticity and its melt behaves as a pseudoplastic liquid at a low shear rate. Its biodegrading extent is slightly higher than that of native starch. The molecular weight of starch displays a decreasing tendency after thermoplastic modification.

Influence of Phase Behavior and Miscibility on Mechanical, Thermal and Micro-Structure of Soluble Starch-Gelatin Thermoplastic Biodegradable Blend Films

Polymer blends of cold water soluble starches (amylose or amylopectin soluble starch) with gelatin were prepared using solvent casting method. The solid state miscibility and polymer-polymer interactions between the constituent polymers were studied by fourier transforms infrared spectroscopy (FTIR), X-ray diffraction (XRD), differential scanning calorirmetry (DSC), light optical microscopy (OP) and scanning electron microscopy (SEM), whereas the thermal stability of the blends was studied by thermogravimetric analysis (TGA). Furthermore, tensile and water vapor barrier properties of the blends were assessed. The obtained results exhibited that gelatin was more miscible with amylose soluble starch than with amylopectin soluble starch. Moreover, enhancing mechanical and water barrier properties of amylose soluble starch/gelatin blends were more pronounced than those of amylopectin soluble starch/gelatin blends. Generally, tensile strength (TS) and Elongation percentage (E) of the blend films were found to be gradually increased with increasing the proportion of gelatin. Nevertheless, increasing starch proportion was in favor of decreasing water vapor permeability (WVP). At equal proportions of starch and gelatin (1:1), TS was raised up to 8.69 MPa for amylose soluble starch/gelatin blend films while it raised up to 4.96 MPa for amylopectin soluble starch/gelatin blend films, and so on E was increased to its maximum by ~179.6% for soluble amylose starch/gelatin blends while it was increased to ~114.5% for amylopectin soluble starch/gelatin blends. On the other hand, WVP was significantly decreased to be 6.46 and 12.09 g·mm/m2·day·kPa for blends of amylose and amylopectin soluble?starches, respectively.

Biodegradation and Mechanical Property of Polylactic Acid/Thermoplastic Starch Blends with Poly (ethylene glycol)

The effects of adding poly （ethylene glycol） （PEG） into polylactic acid/thermoplastic starch blends （PLA/TPS） on the properties were investigated by DSC, SEM and mechanical property-testing. The blends of PLA/TPS blended with increasing content PEG exhibited lower temperature of glass transition （T） and lower temperature of melting （T） as well as higher melt flow index （MFI）, which indicates the plasticization and proeessability of the composites were dramatically improved. The tensile strength, flexural strength and izod impact strength of PLA/TPS （80/20） increased at first and then decreased with increasing content of PEG due to stronger interfacial adhesion. The optimized mechanical property can be obtained for the blend with 3 wt % PEG. The samples containing PEG after soil burial for 5 months showed quicker degradation being accompanied with large weight loss and mechanical properties loss.

Synthesis of aliphatic amidediol and used as a novel mixed plasticizer for thermoplastic starch

In this paper,aliphatic amidediol was synthesized and mixed with glycerol used as a plasticizer for preparing thermoplastic starch（AGPTPS）.The yield of aliphatic amidediol was 91%.FF-IR expressed that the mixture of aliphatic amidediol and glycerol formed stronger and stable hydrogen bond with starch molecules compared to the native cornstarch.By scanning electron microscope（SEM）native cornstarch granules were proved to transfer to a homogeneous continuous system.After being stored for a period time at room temperature,the mechanical properties of AGPTPS were also studied.As a mixed plasticizer,aliphatic amidediol and glycerol would be practical to extend TPS application scopes.

Thermoplastic Starch Prepared with Different Plasticizers: Relation between Degree of Plasticization and Properties

Ethylene glycol, glycerol, sorbitol, formamide, and urea were used as plasticizers for the preparation of thermoplastic starch（TPS） from corn starch. The properties of TPS were tested by analysis method. The results showed that TPSs were more highly plasticized with amines than alcohols. For the same type of plasticizer, the degree of plasticization decreased as the molecular weight of plasticizer increased. The relationship between plasticization degree and TPS properties was characterized and described by mechanical properties and water absorption. The experimental results showed that when the degree of plasticization increased, the tensile strength decreased and the elongation at breakage and water absorption increased.

Studies on Mechanical Properties of Full-Biodegradable Starch-PVA-Polyester Films

A kind of full biodegradable film material is discussed in this article. The film material is composed of starch, PVA, degradable polyesters(PHB, PHB V, PCL) with built plasticizer, a cross linking reinforcing agent and a wet strengthening agent. It contains a high percentage of starch, costs cheap and is excellent in weather fastness, temperature resistance and waterproof and it could be completely biodegraded. The present paper deals mainly with a new technical route using a new type of electromagnetic dynamic blow molding extruder and some effects on mechanical properties of the system.

Progress in Researches on Biodegradable Starch-Based Materials

As one type of environment-friendly polymer, biodegradable starch-based materials have been widely explored in recent years and considered one of the most promising plastics in the future. Currently, either synthetic biodegradable aliphatic polyesters or certain natural polymers are usually blended with thermoplastic starch to enhance hydrophobicity and service performance of starch-based materials. The main deficiency lies in the low compatibility between starch and polyester phases. Therefore amphiphilic compatibilizers, such as hydroxyl functioned polyesters, need to be developed in the future. Moreover, multi-phase blending systems including two or more polyester phases are also supposed to be designed.

A Novel Plasticizer for the Preparation of Thermoplastic Starch

in this paper, ethylenebisformamide was synthesized and used as a novel plasticizer for cornstarch to prepare thermoplastic starch （TPS）. FT-IR expressed that ethylenebisformamide formed stronger and stable hydrogen bond with starch molecules compared to the native cornstarch. X-ray diffraction （XRD） showed that the typical A-style crystallinity in the native starch has been destructed. By scanning electron microscope （SEM） native cornstarch granules were proved to transfer to a homogeneous system. After being stored for one week at RH=33%, the mechanical properties of EPTPS was also studied. The elongation reached to 264% utmost. As a novel plasticizer, ethylenebisformamide would be practical to extend TPS application scopes.

Preparation of Triethylene Glycol Maleate and Its Effect on Plasticization of Oxidized Starch

A plasticizer triethylene glycol maleate（TEG-MA） was synthesized. The dominated monoester of moderate hydrophobicity with apparent oil-water partition coefficient of 0.042 in the product was confirmed by acid value determination, HPLC and FTIR. Its plasticizing effect on oxidized starch was manifested by crystallization, aging behaviour, moisture absorption, and mechanical performance. X-ray diffraction data showed that the relative crystallinity of the plasticized starch decreased. Both the crystal and the crystallinity of starch films were rarely changed in aging. Moisture absorption relied on the ester content and relative humidity. The elongation at break increased significantly with plasticizer content more than 10% in the matrix.

Study on the Properties of Esterified Corn Starch/Polylactide Biodegradable Blends

Fully bio-based and biodegradable starch/polylactic acid blends have received increasing attentions for their biodegradability and potential to offset the use of unsustainable fossil resources,specifically,their application in packaging.Herein,corn starch was first esterified with maleic anhydride and then compounded with polylactide(PLA)to prepare esterified corn starch/polylactic acid blends with starch content up to 35 wt%.The structures,morphologies,thermal and mechanical properties of starch or blends were investigated.The results showed that corn starch was successfully grafted with maleic anhydride,which showed increased crystallinity and particle size than native starch.Esterified corn starch/polylactic acid blends showed good surficial compatibility and good thermal stability with main decomposition temperature in the range of 300℃to 400℃.Additionally,incorporation of corn starch increased the hydrophilicity and water uptake of composites.However,the tensile and flexural strengths of blends decreased with increasing esterified starch amount.

Extrusion of Thermoplastic Starch: Effect of “Green” and Common Polyethylene on the Hydrophobicity Characteristics

Novel plastics that are biodegradable, environmentally benign, and made from renewable natural resources are currently being researched as alternatives to traditional petroleum-based plastics. One such plastic, thermoplastic starch (TPS) is produced from starch processed at high temperatures in the presence of plasticizers, such as water and glycerol. However, because of its hydrophilic nature, TPS exhibits poor mechanical properties when exposed to environmental conditions, such as rain or humidity. The overall objective of this research work was to produce a thermoplastic starch based material with low water absorption that may be used to replace petroleum-based plastics. With a recent emergence of “green” polyethylene (GPE), sourced from renewable feedstock, it has become possible to develop novel biodegradable polymers for various applications. In this work, GPE was melt blended with starch in three different ways;reactive extrusion of GPE and starch facilitated by maleic anhydride (MAH) and dicumyl peroxide (DCP), melt blending of GPE and starch by extrusion, and melt blending of maleated polyethylene and starch by extrusion. Comprehensive testing and analysis has shown that all methods reduced water absorption significantly with some variations across the board.

Biodegradable Colour Polymeric Film (Starch-Chitosan) Development: Characterization for Packaging Materials

Biodegradable starch-based chitosan reinforced composite polymeric films were prepared by casting. The chitosan content in the films was varied from 20% to 80% (w/w). Tensile strength (TS) was improved significantly with the addition of chitosan but elongation at break (EB %) of the composites decreased. Tensile strength of the composites raised more with the addition of the acacia catechu content in the films varied from 0.05% to 0.2% (w/w). The better thermal stability of this prepared film was confirmed by thermo-gravimetric analysis. Structural characterization was done by Fourier transform infrared spectroscopy. Surface morphologies of the composites were examined by scanning electron microscope (SEM) which suggested sufficient homogenization of starch, chitosan and acacia catechu. Water uptake was found lower for final composites in comparison to starch/chitosan and chitosan films. The satisfactory rate of degradation in the soil is expected that the final composite film is within less than 6 months. The developed films intended to use as the alternative of synthetic non-biodegradable colored packaging films.

Structural and Thermomechanical Study of Plastic Films Made from Cassava-Starch Reinforced with Kaolin and Metakaolin

The structural and thermomechanical properties of starch-based plastic films reinforced with kaolin and metakaolin have been studied by various techniques (X-ray diffraction, IR-TF spectroscopy, scanning electron microscopy, tensile tests, and thermal resistance). The results obtained showed that kaolin, an inert material, prevents the starch from losing its granular structure and to solubilize during the heating, generating plastic films of low Young’s modulus (7 MPa). On the other hand, metakaolin, an amorphous and dehydroxylated material obtained after heating of kaolin at 700°C for 1 hour, substantially improves the thermomechanical properties of the plastic films. The Young’s modulus increases from 19 MPa to 25 MPa while the thermal resistance increases from 90°C to 120°C. This was attributed to good dispersion of the metakaolin in the polymer matrix after the loss of the granular structure of the starch during heating.

A Literature Review on Sustainability of Bio-Based and Biodegradable Plastics:Challenges and Opportunities

This study examines the literature on bio-based and biodegradable plastics published between 2000 and 2021 and provides insights and research suggestions for the future.The study gathers data from the Scopus and ISI Web of Science databases,then picks 1042 publications objectively and analyses their metadata.Furthermore,144 papers from the Web of Science are analysed to present insights and classifications of the literature based on content analyses,including assessment/evaluation of the sustainability of bio-based and biodegradable Plastics,sustainability of biodegradable Plastics,and factors driving the uptake of biodegradable plastics.The study finds that most research on bio-based and biodegradable plastic film evaluations considered only one dimension of sustainability,few considered two dimensions,and very few considered three dimensions.Though,in recent years,academic and industrial interest has grown dramatically in biodegradable plastics towards sustainability.The triple bottom line method in this report(economic benefit,social responsibility,and environmental protection)was employed to assess the biodegradable plastics towards sustainability.Top journals,Influential authors,top contributing institutions,top contributing nations,and contributions by fields are all identified in this study.This research gives a detailed but straightforward theoretical design of bio-based and biodegradable polymers.The study’s results and future research initiatives provide a new path for further investigation and contribution to the field.

Starch/PVA降解塑料的X-ray分析与力学性能研究

对以芭蕉芋淀粉、聚乙烯醇为原料制备的生物降解塑料 Ｓｔａｒｃｈ － Ｐ Ｖ Ａ（ 简称 Ｓ－ Ｐ） 进行了 Ｘ 射线分析，并对该塑料膜的力学性能进行了研究．结果表明：随着交联剂的增加， Ｓ－ Ｐ 膜的结晶度有所降低，而拉伸强度有所增大，延伸率出现极大值．这为获得具有较高力学性能的 Ｓ－ Ｐ

Study on Structure and Performance of Starch and Styrene Graft Copolymer

[Objective] The paper was to study the structure and performance of starch and styrene graft copolymer. [Method] The microscopic structure of corn starch and styrene graft copolymer was analyzed by using infrared spectrum and scanning electron microscope, and the property of starch and styrene graft copoly- mer was confirmed through grinding experiment, tensile strength, water absorption rate, hot water resistance properties and enzymatic properties analysis. [Result] The starch and styrene graft copolymer had the properties of thermoplastic and microbial degradation. IConclusion] The starch and styrene graft copolymer is expected to be developed as a biodegradable material.

State of Knowledge on Starch as an Alternative Solution to Petrochemical Resources—A Review

The use of plastics from petrochemical resources poses environmental impacts, and one of the alternative solutions is the use of starch. The objective of this present work has been to present the literature on starch, and to highlight the debate in the development of composite films. The approach adopted was to present the state of the art on starch and thermoplastic starch matrix composites. The work shows that starch is available worldwide and can be used in the manufacture of biodegradable plastics;the debate remains on the reinforcement of thermoplastic starch to improve its physical and mechanical properties poor;then researchers must diversify the reinforcements to see the impact on the properties of thermoplastic starch.

PVA／Starch共混体系的形态、结构和性能

采用聚乙烯醇（ＰＶＡ）与淀粉共混的方法制备自然降解的淀粉塑料薄膜，对不同成分的薄膜进行了结构表征、ＳＥＭ观察、力学性能测定和不同条件下粘度测定及数据处理。