scholarly journals Surface cross-linked thermoplastic starch with different UV wavelengths: mechanical, wettability, hygroscopic and degradation properties

RSC Advances ◽  
2020 ◽  
Vol 10 (73) ◽  
pp. 44815-44823
Author(s):  
Peng Yin ◽  
Chunhao Chen ◽  
Hongpeng Ma ◽  
Huijuan Gan ◽  
Bin Guo ◽  
...  
Keyword(s):  
Thermoplastic Starch ◽  
Cross Linking ◽  
Degradation Properties

Here, we report a method to improve the properties of thermoplastic starch (TPS) by surface ultraviolet (UV) cross-linking.

scholarly journals Synthesis and characterization of thermoresponsive hydrogels cross-linked with chitosan

2008 ◽  
Vol 6 (1) ◽  
pp. 107-113 ◽  
Author(s):  
Yueqin Yu ◽  
Xianzhi Chang ◽  
Hansheng Ning ◽  
Shusheng Zhang
Keyword(s):  
Acrylic Acid ◽  
Pure Water ◽  
Solution Temperature ◽  
Feed Ratio ◽  
Cross Linking ◽  
Environmentally Responsive ◽  
Extracellular Materials ◽  
Degradation Properties ◽  
Phosphate Buffered Saline

AbstractHydrogels composed of N-isopropylacrylamide (NIPAAm) and acrylic acid (AAc) were prepared by redox polymerization with degradable chitosan cross-linkers. Chitosan degradable cross-linkers were synthesized by the acrylation of the amine groups of glucosamine units within chitosan and characterized with 1H NMR. With the chitosan cross-linkers, loosely cross-linked poly(N-isopropylacryamideco-acrylic acid) [P(NIPAAm-co-AAc)] hydrogels were prepared, and their phase transition behavior, lower critical solution temperature (LCST), water content and degradation properties were investigated. The chitosan cross-linked P(NIPAAm-co-AAc) hydrogels were pliable and transparent at room temperature. The LCST could be adjusted at 32∼39°C by alternating the feed ratio. Swelling was influenced by NIPAAm/AAc monomer ratio, cross-linking density, swelling media, and temperature. All hydrogels with different feeding ratios contained more than 95% water at 25°C in the ultra pure water and phosphate-buffered saline (PBS, pH = 7.4 ± 0.1), and had a prospective swelling in the simulated gastric fluids (SGF, pH = 1.2) > 72.54%. In degradation studies, breakdown of the chitosan cross-linked P(NIPAAm-co-AAc) hydrogels was dependent on the cross-linking density. The chitosan cross-linked P(NIPAAm-co-AAc) hydrogels which can be tailored to create environmentally-responsive artificial extracellular materials have great potential for future use.

Modifications of Biodegradable Thermoplastic Starch (TPS) From Sago Starch via Cross-Linking Method

2020 ◽  
pp. 77-91
Author(s):  
Yusriah Lazim ◽  
Abdul Baith Abu Hanafi ◽  
Mohd Syazwan Adura ◽  
Siti Afifah Muda ◽  
Lily Suhaila Yacob ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermoplastic Starch ◽  
Environmental Problems ◽  
Cross Linking ◽  
Palm Tree ◽  
Sago Starch ◽  
Sago Palm ◽  
Starch Modification ◽  
Literature Overview ◽  
Plant Sources

The increasing amount of synthetic plastic waste has contributed to environmental problems worldwide. As an alternative to synthetic plastics, thermoplastic starch (TPS) has been used for many applications, especially packaging application, since TPS provides good biodegradation and ease of disposal and reducing the consumption of petroleum. However, TPS tends to experience loss in mechanical properties and stability due to retrogradation of the starch. Modification of starch is often carried out to overcome this shortcoming in TPS. TPS can be made of various type of starch from various plant sources such as corn, cassava, rice, and potato. Sago starch is a plant-based starch that originates from the sago palm tree. The chapter aims to give a short literature overview on the sago starch, issues related to starch and thermoplastic starch, modification of sago starch via crosslinking method, properties of crosslinked sago starch, and limitation and opportunities of modification of sago starch via crosslinking method.

Effect of ultra-violet cross-linking on the properties of boric acid and glycerol co-plasticized thermoplastic starch films

2019 ◽  
Vol 19 ◽  
pp. 184-192 ◽  
Author(s):  
Bahram Khan ◽  
Muhammad Bilal Khan Niazi ◽  
Zaib Jahan ◽  
Wasif Farooq ◽  
Salman Raza Naqvi ◽  
...  
Keyword(s):  
Boric Acid ◽  
Ultra Violet ◽  
Thermoplastic Starch ◽  
Cross Linking ◽  
Starch Films

Cross-Linking and Degradation Properties of Plasma Enhanced Chemical Vapor Deposited Poly(2-hydroxyethyl methacrylate)

2008 ◽  
Vol 30 (2) ◽  
pp. 126-132 ◽  
Author(s):  
Courtney A. Pfluger ◽  
Rebecca L. Carrier ◽  
Bing Sun ◽  
Katherine S. Ziemer ◽  
Daniel D. Burkey
Keyword(s):  
Chemical Vapor ◽  
Cross Linking ◽  
Hydroxyethyl Methacrylate ◽  
Chemical Vapor Deposited ◽  
Degradation Properties

Preparation of Cross-Linked Sodium Hyaluronate Gels with Different Molecular Weights of PEG and Research for its Viscoelasticity and Enzyme-Resistant Properties In Vitro

2011 ◽  
Vol 399-401 ◽  
pp. 1552-1558
Author(s):  
Wei Guo Wang ◽  
Yu Jia Cui ◽  
Peng Li ◽  
Yong Liang Zhao ◽  
Ya Nan Gu ◽  
...  
Keyword(s):  
Orthogonal Experiment ◽  
Sodium Hyaluronate ◽  
Cross Linking ◽  
Optimal Conditions ◽  
Range Analysis ◽  
Molecular Weights ◽  
Enzyme Degradation ◽  
Degradation Properties ◽  
Significant Factors

Abstract: Purpose To screen out the optimal conditions of cross-linking reaction of preparing for an injectable cross-linked sodium hyaluronate gel(CHA-gel) with higher resistance to hyaluronidase and research for its viscoelasticity and anti-enzyme degradation properties. Methods The CHA hydrogels were prepared with different molecular weights of PEG as cross-linking agent, such as PEG400, PEG1000, PEG6000, PEG10000, PEG20000. The optimal preparing conditions were determined by single factor test and orthogonal experiment. The Enzyme-resistant degradation properties in vitro of CHA-gels were analysed by carbazole and spectrophotometry. Its viscoelasticity was also compared with natural HA-gel by Stabinger method. Results the results of range analysis and variance analysis show that the pH of CHA solution and the ratio of cross-linking agent to HA were significant factors. The optimal preparing conditions of the parameters are 1.5% of HA, 0.001mol/L NaOH, at 37°C, reacting 4hr and 1:15 PEG20000/HA (g/g). Under these conditions, the CHA-gel has excellent Enzyme-resistant properties, R=85.1%, an high percentage of enzyme-resistant property. Its viscoelasticity can reach 61.3×104mPa.s, three times as much as natural HA-gel. Conclusion The CHA-gel with excellent physicochemical properties can be prepared under the optimal conditions, which can set foundation for developing better mechanical and Enzyme-resistant properties products of CHA-gel.

scholarly journals Tartaric Acid Cross-Linking of Starch: Effect of Reaction Conditions on the Maximum Tensile Strength of Cast Plastic Films

2015 ◽  
Vol 8 (3) ◽  
Author(s):  
Arturo José Mendoza
Keyword(s):  
Tensile Strength ◽  
Tartaric Acid ◽  
Low Cost ◽  
Thermoplastic Starch ◽  
Cross Linking ◽  
Reaction Conditions ◽  
Maximum Tensile Strength ◽  
Polycarboxylic Acids ◽  
The Cross ◽  
London Dispersion

Modification of starch by cross-linking is used in many fields, as the process improves many of the properties of starch, yet most cross-linking agents in common use tend to be toxic, expensive, or both. Polycarboxylic acids could function as nontoxic alternatives to these – some, such as tartaric acid (TA) being also of low cost. This study presents a method to cross-link thermoplastic starch films with TA, as well as the effect of this modification on the tensile strength of the material when films are prepared using different reaction conditions. An increase in strength was observed, which is believed to occur due to an increase in the London dispersion forces acting within the cross-linked starch (CLS). The greatest observed increase in the maximum tensile strength of the plastic was 6%. Monosodium tartrate was used as a catalyst for the cross-linking reaction. The maximum tensile strengths of the plastics produced were determined by using adapted binder clips, a hook (total mass 10g) and hanging masses to subject films of the plastics to progressively greater tension. Incremental weights of 10g were used, with recorded tensions at fracture of 1.2~8.9 N.

Solid-state photo-cross-linking of cassava starch: improvement properties of thermoplastic starch

2017 ◽  
Vol 75 (8) ◽  
pp. 3341-3356 ◽  
Author(s):  
Amirah Hulwani Mohd Zain ◽  
Mohamad Kahar Abdul Wahab ◽  
Hanafi Ismail
Keyword(s):  
Solid State ◽  
Thermoplastic Starch ◽  
Cassava Starch ◽  
Cross Linking

Influence of Calcium Ions on the Plant Cell Surface: Membrane Fusions and Conformational Changes

1974 ◽  
Vol 32 ◽  
pp. 154-155
Author(s):  
D. James Morré ◽  
Charles E. Bracker ◽  
William J. VanDerWoude
Keyword(s):  
Cell Wall ◽  
Cell Surface ◽  
Conformational Changes ◽  
Calcium Ions ◽  
Surface Membrane ◽  
Carboxyl Groups ◽  
Cross Linking ◽  
Ultrastructural Evidence ◽  
Glycine Max L ◽  
Wall Extensibility

Calcium ions in the concentration range 5-100 mM inhibit auxin-induced cell elongation and wall extensibility of plant stems. Inhibition of wall extensibility requires that the tissue be living; growth inhibition cannot be explained on the basis of cross-linking of carboxyl groups of cell wall uronides by calcium ions. In this study, ultrastructural evidence was sought for an interaction of calcium ions with some component other than the wall at the cell surface of soybean (Glycine max (L.) Merr.) hypocotyls.

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