Characteristics of Self-Healable Copolymers of Styrene and Eugenol Terminated Polyurethane Prepolymer

With limited biomass that can be currently utilized as a renewable resource, it is important to develop a method to convert biomass into materials that can replace fossil fuel product. In this paper, eugenol, a bio-based allyl chain-substituted guaiacol, was used to synthesize self-healable copolymers. Eugenol terminated polyurethane prepolymer (ETPU) was synthesized from eugenol and polyurethane prepolymers terminated with isocyanate groups. ETPU contained two allyl groups. Self-healing copolymer networks were obtained by copolymerization of ETPU and styrene monomer via free radical polymerization. Effects of ETPU content on the properties of copolymers were then studied. These copolymers containing ETPU exhibited good thermal stability and mechanical properties. These copolymers showed higher tensile strength and elongation at break than PS. Their maximum tensile strength reached 19 MPa. In addition, these copolymers showed self-healing property at elevated temperature due to the reversible nature of urethane units in ETPU.

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Experimental assessment on preparation of biodegradable polythylene/polylatic acid-chithosan composite from renewable resources

Bayero Journal of Pure and Applied Sciences ◽

10.4314/bajopas.v14i1.7 ◽

2021 ◽

Vol 14 (1) ◽

pp. 45-53

Author(s):

B.U. Gumel ◽

S.M. Gumel ◽

A.A. Bawa ◽

A.S. Auwal

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Polylactic Acid ◽

Renewable Resources ◽

Enzymatic Degradation ◽

Renewable Resource ◽

Natural Polymers ◽

Homogeneous Surface ◽

Elongation At Break ◽

Potato Waste

Due to poor degradability and contamination risk of synthetic plastics, utilization of renewable resources is encouraged. Biobased thermoplastic polymers from renewable resource that is inexpensive, biodegradable, compostable and renewably non-toxic, is focused. In this paper mixtures of synthetic and natural polymers were used as a potential option to reduce pollution by plastic waste. The study is aimed at assessing utilization of sweet potato waste as a source of bioplastic for package application, the polymer was modified with a biopolymer chitosan to obtain polylactic acid-chitosan plastic. The developed polymer matrix was blended with polyethylene to obtain biodegradable packaging material. The bioplastic was characterized using Fourier Transformed Infra-Red Spectroscopy (FTIR) and scaning electron microscope (SEM). Physical and mechanical properties of the composites were evaluated by measuring enzymatic degradation, tensile strength, and elongation at break. The results have shown that the film obtained have homogeneous surface by (SEM). Mechanical properties of the bio plastics revealed that tensile strength increases with increases in the concentration of chitosan and hence, the elongation at break decreases with increase in chitosan content. While the fastest enzymatic degradation was observed to have high microbial growth on the bio plastics with high content of Chitosan-Polylactic acid.

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The Structure and Mechanical Properties of Hemp Fibers-Reinforced Poly(ε-Caprolactone) Composites Modified by Electron Beam Irradiation

Applied Sciences ◽

10.3390/app11125317 ◽

2021 ◽

Vol 11 (12) ◽

pp. 5317

Author(s):

Rafał Malinowski ◽

Aneta Raszkowska-Kaczor ◽

Krzysztof Moraczewski ◽

Wojciech Głuszewski ◽

Volodymyr Krasinskyi ◽

...

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Electron Beam ◽

Impact Strength ◽

Flexural Modulus ◽

Natural Fibers ◽

High Energy ◽

Electron Radiation ◽

Elongation At Break ◽

Hemp Fibers

The need for the development of new biodegradable materials and modification of the properties the current ones possess has essentially increased in recent years. The aim of this study was the comparison of changes occurring in poly(ε-caprolactone) (PCL) due to its modification by high-energy electron beam derived from a linear electron accelerator, as well as the addition of natural fibers in the form of cut hemp fibers. Changes to the fibers structure in the obtained composites and the geometrical surface structure of sample fractures with the use of scanning electron microscopy were investigated. Moreover, the mechanical properties were examined, including tensile strength, elongation at break, flexural modulus and impact strength of the modified PCL. It was found that PCL, modified with hemp fibers and/or electron radiation, exhibited enhanced flexural modulus but the elongation at break and impact strength decreased. Depending on the electron radiation dose and the hemp fibers content, tensile strength decreased or increased. It was also found that hemp fibers caused greater changes to the mechanical properties of PCL than electron radiation. The prepared composites exhibited uniform distribution of the dispersed phase in the polymer matrix and adequate adhesion at the interface between the two components.

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Effect of Moisture Content on the Processing and Mechanical Properties of a Biodegradable Polyester

Polymers ◽

10.3390/polym13101616 ◽

2021 ◽

Vol 13 (10) ◽

pp. 1616

Author(s):

Vincenzo Titone ◽

Antonio Correnti ◽

Francesco Paolo La Mantia

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Moisture Content ◽

Mechanical Testing ◽

Hydrolytic Degradation ◽

Slight Reduction ◽

Biodegradable Polyester ◽

Molding Process ◽

Elongation At Break ◽

Effect Of Moisture

This work is focused on the influence of moisture content on the processing and mechanical properties of a biodegradable polyester used for applications in injection molding. The pellets of the biodegradable polyester were exposed under different relative humidity conditions at a constant temperature before being compression molded. The compression-molded specimens were again placed under the above conditions before the mechanical testing. With all these samples, it is possible to determine the effect of moisture content on the processing and mechanical properties separately, as well as the combined effect of moisture content on the mechanical properties. The results obtained showed that the amount of absorbed water—both before processing and before mechanical testing—causes an increase in elongation at break and a slight reduction of the elastic modulus and tensile strength. These changes have been associated with possible hydrolytic degradation during the compression molding process and, in particular, with the plasticizing action of the moisture absorbed by the specimens.

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Effect of Castor Oil Impregnation on the Physical and Mechanical Properties of Bacterial Cellulose

Polymers from Renewable Resources ◽

10.1177/204124791200300102 ◽

2012 ◽

Vol 3 (1) ◽

pp. 13-26

Author(s):

Myrtha Karina ◽

Lucia Indrarti ◽

Rike Yudianti ◽

Indriyati

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Bacterial Cellulose ◽

Young’S Modulus ◽

Castor Oil ◽

Young's Modulus ◽

Physical And Mechanical Properties ◽

Scanning Electron Micrographs ◽

Elongation At Break ◽

Acetone Water

The effect of castor oil on the physical and mechanical properties of bacterial cellulose is described. Bacterial cellulose (BC) was impregnated with 0.5–2% (w/v) castor oil (CO) in acetone–water, providing BCCO films. Scanning electron micrographs revealed that the castor oil penetrated the pores of the bacterial cellulose, resulting in a smoother morphology and enhanced hydrophilicity. Castor oil caused a slight change in crystallinity indices and resulted in reduced tensile strength and Young's modulus but increased elongation at break. A significant reduction in tensile strength and Young's modulus was achieved in BCCO films with 2% castor oil, and there was an improvement in elongation at break and hydrophilicity. Impregnation with castor oil, a biodegradable and safe plasticiser, resulted in less rigid and more ductile composites.

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Numerical Studies of the Effects of Water Capsules on Self-Healing Efficiency and Mechanical Properties in Cementitious Materials

Advances in Materials Science and Engineering ◽

10.1155/2016/8271214 ◽

2016 ◽

Vol 2016 ◽

pp. 1-10 ◽

Cited By ~ 1

Author(s):

Haoliang Huang ◽

Guang Ye

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Elastic Modulus ◽

Cementitious Materials ◽

Self Healing ◽

Negative Effects ◽

Numerical Studies ◽

Healing Efficiency ◽

The Impact ◽

Positive Effect

In this research, self-healing due to further hydration of unhydrated cement particles is taken as an example for investigating the effects of capsules on the self-healing efficiency and mechanical properties of cementitious materials. The efficiency of supply of water by using capsules as a function of capsule dosages and sizes was determined numerically. By knowing the amount of water supplied via capsules, the efficiency of self-healing due to further hydration of unhydrated cement was quantified. In addition, the impact of capsules on mechanical properties was investigated numerically. The amount of released water increases with the dosage of capsules at different slops as the size of capsules varies. Concerning the best efficiency of self-healing, the optimizing size of capsules is 6.5 mm for capsule dosages of 3%, 5%, and 7%, respectively. Both elastic modulus and tensile strength of cementitious materials decrease with the increase of capsule. The decreasing tendency of tensile strength is larger than that of elastic modulus. However, it was found that the increase of positive effect (the capacity of inducing self-healing) of capsules is larger than that of negative effects (decreasing mechanical properties) when the dosage of capsules increases.

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Graphite/Bio-Based Epoxy Composites: The Mechanical Properties Interface

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.799-800.115 ◽

2015 ◽

Vol 799-800 ◽

pp. 115-119 ◽

Cited By ~ 3

Author(s):

Anika Zafiah M. Rus ◽

Nur Munirah Abdullah ◽

M.F.L. Abdullah ◽

M. Izzul Faiz Idris

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Elastic Modulus ◽

Filler Content ◽

Weight Percent ◽

Epoxy Composites ◽

Elongation At Break ◽

Graphite Content ◽

Dispersion Condition ◽

Strong Interfacial Bonding

Graphite reinforced bio-based epoxy composites with different particulate fractions of graphite were investigated for mechanical properties such as tensile strength, elastic modulus and elongation at break. The graphite content was varied from 5 wt.%, 10 wt.%, 15 wt.%, 20 wt.%, 25 wt.%, 30 wt.% by weight percent in the composites. The results showed that the mechanical properties of the composites mainly depend on dispersion condition of the treated graphite filler, aggregate structure and strong interfacial bonding between treated graphite in the bio-based epoxy matrix. The composites showed improved tensile strength and elastic modulus with increase treated graphite weight loading. This also revealed the composites with increasing filler content was decreasing the elongation at break.

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Fabrication and Characterization of Electrospun Polycaprolactone Blended with Chitosan-Gelatin Complex Nanofibrous Mats

Journal of Nanomaterials ◽

10.1155/2014/964621 ◽

2014 ◽

Vol 2014 ◽

pp. 1-7 ◽

Cited By ~ 20

Author(s):

Yongfang Qian ◽

Zhen Zhang ◽

Laijiu Zheng ◽

Ruoyuan Song ◽

Yuping Zhao

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Weight Ratio ◽

Degree Of Crystallinity ◽

X Ray Diffraction ◽

Tissue Engineering Scaffolds ◽

Elongation At Break ◽

Nanofibrous Scaffolds ◽

Two Peaks

Design and fabrication of nanofibrous scaffolds should mimic the native extracellular matrix. This study is aimed at investigating electrospinning of polycaprolactone (PCL) blended with chitosan-gelatin complex. The morphologies were observed from scanning electron microscope. As-spun blended mats had thinner fibers than pure PCL. X-ray diffraction was used to analyze the degree of crystallinity. The intensity at two peaks at 2θof 21° and 23.5° gradually decreased with the percentage of chitosan-gelatin complex increasing. Moreover, incorporation of the complex could obviously improve the hydrophilicity of as-spun blended mats. Mechanical properties of as-spun nanofibrous mats were also tested. The elongation at break of fibrous mats increased with the PCL content increasing and the ultimate tensile strength varied with different weight ratios. The as-spun mats had higher tensile strength when the weight ratio of PCL to CS-Gel was 75/25 compared to pure PCL. Both as-spun PCL scaffolds and PCL/CS-Gel scaffolds supported the proliferation of porcine iliac endothelial cells, and PCL/CS-Gel had better cell viability than pure PCL. Therefore, electrospun PCL/Chitosan-gelatin nanofibrous mats with weight ratio of 75/25 have better hydrophilicity mechanical properties, and cell proliferation and thus would be a promising candidate for tissue engineering scaffolds.

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Synthesis of Cyclic Polysulfides and their Properties as Curing Agents

Rubber Chemistry and Technology ◽

10.5254/1.3547830 ◽

2004 ◽

Vol 77 (2) ◽

pp. 380-390

Author(s):

Wonmun Choi ◽

Tomoyuki Matsumura

Keyword(s):

Mechanical Properties ◽

Molecular Weight ◽

Tensile Strength ◽

High Molecular Weight ◽

Mass Spectra ◽

Elongation At Break ◽

Molecular Weights ◽

Aging Properties ◽

Curing Agents ◽

Polysulfide Polymer

Abstract The reactions of dichloroalkanes and sodium tetra-sulfide (Na2S4) were carried out in a mixture of water and toluene to produce corresponding cyclic polysulfides and polysulfide polymer. The low molecular weights of cyclic sulfides were obtained by the reaction at 90 °C, while the high molecular weight of polysulfide polymer was obtained by the reaction at 50 °C. GPC chromatograms and Mass spectra revealed that the structures of cyclic polysulfide were 1:1, 2:2, and 3:3 adducts of dichloroalkane and sodium tetra-sulfide. The mechanical properties of vulcanized NR at 148 °C with cyclic sulfides were similar to that with sulfur. However, both tensile strength and elongation at break of vulcanized NR at 170 °C with cyclic sulfides are much higher than that with sulfur. The aging properties of vulcanized NR at 148 °C or 170 °C with cyclic polysulfides indicate better stability.

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The effect of large area graphene oxide (LAGO) nanosheets on the mechanical properties of polyvinyl alcohol

Journal of Polymer Engineering ◽

10.1515/polyeng-2015-0271 ◽

2016 ◽

Vol 36 (4) ◽

pp. 399-405 ◽

Cited By ~ 1

Author(s):

Khalid Nawaz ◽

Muhammad Ayub ◽

Noaman Ul-Haq ◽

M.B. Khan ◽

Muhammad Bilal Khan Niazi ◽

...

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Graphene Oxide ◽

Polyvinyl Alcohol ◽

Molecular Level ◽

Large Area ◽

Graphene Oxides ◽

Elongation At Break ◽

Graphene Oxide Sheets ◽

Excellent Improvement

Abstract Large area graphene oxide sheets were synthesized, dispersed in water and used as nanofiller for mechanical improvement in terms of Young’s modulus and ultimate tensile strength (UTS) of polyvinyl alcohol (PVA) at low loading. The molecular level dispersion and interfacial interactions between the graphene oxides and polymeric matrix PVA were the real challenges. An excellent improvement in mechanical properties at 0.35 wt% loading was observed. Modulus improved from 1.58 GPa to 2.72 GPa (~71% improvement), UTS improved from 120 MPa to 197 MPa (~65% improvement), and in spite of these improvements, interestingly, there was no fall in elongation at break at this loading.

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Preparation and characterizations of ternary biodegradable blends composed of polylactide, poly(ε-caprolactone), and wood flour

Journal of Polymer Engineering ◽

10.1515/polyeng-2012-0043 ◽

2012 ◽

Vol 32 (6-7) ◽

pp. 435-444 ◽

Cited By ~ 3

Author(s):

Hsin-Tzu Liao ◽

Chin-San Wu

Keyword(s):

Mechanical Properties ◽

Weight Loss ◽

Tensile Strength ◽

Fourier Transform ◽

Wood Flour ◽

High Price ◽

Infrared Analysis ◽

Melt Blending ◽

Ternary Blends ◽

Elongation At Break

Abstract Melt blending of polylactide (PLA), poly(ε-caprolactone) (PCL), and wood flour (WF) was performed in an effort to overcome the major drawbacks (brittleness and high price) of PLA. In addition, the acrylic acid (AA)-grafted PLA70PCL30 (PLA70PCL30-g-AA) was used as the alternative for the preparation of ternary blends to improve the compatibility and the dispersability of WF within the PLA70PCL30 matrix. As expected, PCL improved the elongation at break and the toughness of PLA but decreased the tensile strength and modulus. Because the hydrophilic WF is dispersed physically in the hydrophobic PLA70PCL30 matrix, as the result of Fourier transform infrared analysis, the mechanical properties of PLA70PCL30 became noticeably worse when it was blended with WF. This problem was successfully conquered by using PLA70PCL30-g-AA to replace PLA70PCL30 due to the formation of an ester carbonyl group between PLA70PCL30-g-AA and WF. Furthermore, the PLA70PCL30-g-AA/WF blend provided a plateau tensile strength at break when the WF content was up to 50 wt%. PLA70PCL30/WF exhibited a tensile strength at break of approximately 3–25 MPa more than PLA70PCL30-g-AA/WF. By using p-cresol and tyrosinase, the enzymatic biodegradable test showed that PLA70PCL30-g-AA is somewhat more biodegradable than PLA70PCL30 because the former has better water absorption. After 16 weeks, the weight loss of the PLA70PCL30/WF (50 wt%) composite was >80%. PLA70PCL30-g-AA/WF exhibited a weight loss of approximately 1–12 wt% more than PLA70PCL30-g-AA/WF. It was also found that the addition of WF to PLA70PCL30 or PLA70PCL30-g-AA decreased the crystallinity of PLA and PCL in PLA70PCL30 or PLA70PCL30-g-AA and then increased their biodegradable property.

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