Preparation and characterization of biodegradable blends of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) and poly(butylene adipate-co-terephthalate)

2016 ◽  
Vol 36 (5) ◽  
pp. 473-480 ◽  
Author(s):  
Min Zhang ◽  
Xiaoqian Diao ◽  
Yujuan Jin ◽  
Yunxuan Weng
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Thermal Properties ◽  
Crystallization Temperature ◽  
Molecular Interaction ◽  
Mechanical And Thermal Properties ◽  
Elongation At Break ◽  
Tear Strength ◽  
Biodegradable Blends

Abstract Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH) was blended with poly(butylene adipate-co-terephthalate) (PBAT) by extrusion at different weight ratios (PHBH/PBAT: 100:0, 80:20, 60:40, 50:50, 40:60, 20:80 and 0:100). Films were then prepared from the blends and characterized in terms of their morphological, rheological, mechanical and thermal properties. The morphological and rheological results indicated that PHBH/PBAT blends are immiscible but exhibit possible molecular interaction. The crystallization temperature of PHBH in the blends decreased, indicating that the addition of PBAT inhibited the crystallization of PHBH. Blending PBAT with PHBH improved the processability compared with that of pure polymers. The mechanical properties, including tensile strength, elongation at break and tear strength, increased with increasing PBAT content. The PHBH/PBAT 20:80 blend exhibited significantly improved mechanical properties, which was due to the reinforcing and toughening effect of the finely dispersed PHBH phase.

scholarly journals Preparation and Characterization of Modified Natural Rubber Blends For Water Purification Treatment Usage

2020 ◽  
Author(s):  
Ruogu Tang ◽  
Wenfa Dong
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Relative Volume ◽  
Curing Time ◽  
Water Industry ◽  
High Modulus ◽  
Elongation At Break ◽  
Tear Strength ◽  
Rubber Blends

<div>The water industry used NR was selected for blending with SBR. A series of NR/SBR vulcanizates were prepared through three different vulcanization systems, conventional vulcanization (CV), effective vulcanization (EV) and semi-effective vulcanization (SEV) respectively, basing on each formulation and optimum curing time. We examined the mechanical properties of NR/SBR vulcanizates including tensile strength, tear strength, elongation at break, modulus, Shore A hardnessand and relative volume abrasion. The results indicated that NR/SBR vulcanizates prepared in different systems differed in mechanical properties. Vulcanizates prepared via CV showed higher tensile and tear strength; vulcanizates prepared via EV had high modulus and hardness, and vulcanizates prepared via SEV performed high abrasion resistance. </div>

scholarly journals Preparation and Characterization of Modified Natural Rubber Blends For Water Purification Treatment Usage

2020 ◽  
Author(s):  
Ruogu Tang ◽  
Wenfa Dong
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Relative Volume ◽  
Curing Time ◽  
Water Industry ◽  
High Modulus ◽  
Elongation At Break ◽  
Tear Strength ◽  
Rubber Blends

<div>The water industry used NR was selected for blending with SBR. A series of NR/SBR vulcanizates were prepared through three different vulcanization systems, conventional vulcanization (CV), effective vulcanization (EV) and semi-effective vulcanization (SEV) respectively, basing on each formulation and optimum curing time. We examined the mechanical properties of NR/SBR vulcanizates including tensile strength, tear strength, elongation at break, modulus, Shore A hardnessand and relative volume abrasion. The results indicated that NR/SBR vulcanizates prepared in different systems differed in mechanical properties. Vulcanizates prepared via CV showed higher tensile and tear strength; vulcanizates prepared via EV had high modulus and hardness, and vulcanizates prepared via SEV performed high abrasion resistance. </div>

Effect of Algerian Halloysite on the Mechanical and Thermal Properties of Starch-Grafted-Polyethylene Nanocomposites

2018 ◽  
Vol 762 ◽  
pp. 192-196 ◽  
Author(s):  
Walid Fermas ◽  
Remo Merijs Meri ◽  
Mustapha Kaci ◽  
Janis Zicans
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Thermal Properties ◽  
Melt Flow Index ◽  
Halloysite Nanotubes ◽  
Polymer Chains ◽  
Flow Index ◽  
Mechanical And Thermal Properties ◽  
Melt Compounding

This paper deals with the characterization of the physico-mechanical properties of starch-grafted-polyethylene (Starch-g-PE)/unmodified Algerian halloysite nanotubes (HNT) nanocomposites prepared by melt compounding. The nanoclay was incorporated at various filler contents, i.e., 1.5, 3 and 5 wt%. Rheological and tensile properties of the nanocomposites were evaluated by different techniques and the results obtained are compared with those of virgin Starch-g-PE matrix. The study shows a decrease in melt flow index (MFI) values upon increasing the HNT content, which indicates a restriction in the polymer chains mobility due to the confinement effect of HNT. Further, a tensile strength is also improved.

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

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
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.

Mechanochemical Devulcanization of Vulcanized Gum Natural Rubber

2005 ◽  
Vol 21 (3) ◽  
pp. 183-199
Author(s):  
G.K. Jana ◽  
C.K. Das
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Natural Rubber ◽  
Three Dimensional ◽  
Elongation At Break ◽  
Tear Strength ◽  
Vulcanized Rubber ◽  
Dimensional Network ◽  
Polymeric Chains ◽  
Cure Time

De-vulcanization of vulcanized elastomers represents a great challenge because of their three-dimensional network structure. Sulfur-cured gum natural rubbers containing three different sulfur/accelerator ratios were de-vulcanized by thio-acids. The process was carried out at 90 °C for 10 minutes in an open two-roll cracker-cum-mixing mill. Two concentrations of de-vulcanizing agent were tried in order to study the cleavage of the sulfidic bonds. The mechanical properties of the re-vulcanized rubber (like tensile strength, modulus, tear strength and elongation at break) were improved with increasing concentrations of de-vulcanizing agent, because the crosslink density increased. A decrease in scorch time and in optimum cure time and an increase in the state of cure were observed when vulcanized rubber was treated with high amounts of de-vulcanizing agent. The temperature of onset of degradation was also increased with increasing concentration of thio-acid. DMA analysis revealed that the storage modulus increased on re-vulcanization. From IR spectroscopy it was observed that oxidation of the main polymeric chains did not occur at the time of high temperature milling. Over 80% retention of the original mechanical properties (like tensile strength, modulus, tear strength and elongation at break) of the vulcanized natural rubber was achieved by this mechanochemical process.

scholarly journals Effect of Selected Commercial Plasticizers on Mechanical, Thermal, and Morphological Properties of Poly(3-hydroxybutyrate)/Poly(lactic acid)/Plasticizer Biodegradable Blends for Three-Dimensional (3D) Print

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1893 ◽  
Author(s):  
Přemysl Menčík ◽  
Radek Přikryl ◽  
Ivana Stehnová ◽  
Veronika Melčová ◽  
Soňa Kontárová ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Thermal Properties ◽  
Three Dimensional ◽  
Poly Lactic Acid ◽  
Mechanical And Thermal Properties ◽  
Modulated Differential Scanning Calorimetry ◽  
3D Print ◽  
3D Printed ◽  
Biodegradable Blends

This paper explores the influence of selected commercial plasticizers structure, which are based on esters of citric acid, on mechanical and thermal properties of Poly(3-hydroxybutyrate)/Poly(lactic acid)/Plasticizer biodegradable blends. These plasticizers were first tested with respect to their miscibility with Poly(3-hydroxybutyrate)/Poly(lactic acid) (PHB/PLA) blends using a kneading machine. PHB/PLA/plasticizer blends in the weight ratio (wt %) of 60/25/15 were then prepared by single screw and corotating meshing twin screw extruders in the form of filament for further three-dimensional (3D) printing. Mechanical, thermal properties, and shape stability (warping effect) of 3D printed products can be improved just by the addition of appropriate plasticizer to polymeric blend. The goal was to create new types of eco-friendly PHB/PLA/plasticizers blends and to highly improve the poor mechanical properties of neat PHB/PLA blends (with majority of PHB) by adding appropriate plasticizer. Mechanical properties of plasticized blends were then determined by the tensile test of 3D printed test samples (dogbones), as well as filaments. Measured elongation at break rapidly enhanced from 21% for neat non-plasticized PHB/PLA blends (reference) to 328% for best plasticized blends in the form of filament, and from 5% (reference) to 187% for plasticized blends in the form of printed dogbones. The plasticizing effect on blends was confirmed by Modulated Differential Scanning Calorimetry. The study of morphology was performed by the Scanning Electron Microscopy. Significant problem of plasticized blends used to be also plasticizer migration, therefore the diffusion of plasticizers from the blends after 15 days of exposition to 110 °C in the drying oven was investigated as their measured weight loss. Almost all of the used plasticizers showed meaningful positive softening effects, but the diffusion of plasticizers at 110 °C exposition was quite extensive. The determination of the degree of disintegration of selected plasticized blend when exposed to a laboratory-scale composting environment was executed to roughly check the “biodegradability”.

MECHANICAL AND THERMAL PROPERTIES OF SAWDUST CONCRETE

2017 ◽  
Vol 79 (6) ◽  
Author(s):  
Ruhal Pervez Memon ◽  
Abdul Rahman Mohd. Sam ◽  
A. S. M. Abdul Awal ◽  
Lemar Achekzai
Keyword(s):  
Heat Transfer ◽  
Mechanical Properties ◽  
Tensile Strength ◽  
Thermal Properties ◽  
Lightweight Concrete ◽  
Physical And Mechanical Properties ◽  
Developing Nations ◽  
Mechanical And Thermal Properties ◽  
Construction Technology ◽  
Long Duration

 Industrialization in developing countries has resulted in an increase in agricultural output and consequent accumulation of unmanageable agro wastes. Pollution arising from such wastes is a matter of concern for many developing nations. The aim of this study is to investigate the behavior of lightweight concrete and the utilization of sawdust as waste material in concrete. This paper focuses on the manufacturing of concrete which possess long duration heat transfer by using sawdust waste. In this research, cement to sawdust ratio of 1:1, 1:2 and 1:3 by volume was prepared for sawdust concrete, and the ratio of sand was kept constant that is 1. At these ratios, the mechanical and thermal properties like density, workability, strength and heat transfer were measured after, 7, 28 and 56 days of air curing. The tests results show that with the increase in the amount of sawdust, the workability, compressive strength, tensile strength and flexural strength decreased. It also resulted in reduction of heat transfer of sawdust concrete. Taking into account the overall physical and mechanical properties, sawdust concrete can be used in construction technology. 

Influences of Particle Sizes on Properties of Natural Rubber/Waste Ground Rubber Powders Blends

2013 ◽  
Vol 773 ◽  
pp. 668-672
Author(s):  
Jun Liang Liu ◽  
Ping Liu ◽  
Xiao Qiang Tang ◽  
Dong Zeng ◽  
Xing Kai Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Natural Rubber ◽  
Chemical Activation ◽  
Cross Linking ◽  
Particle Sizes ◽  
Elongation At Break ◽  
Tear Strength ◽  
Rubber Waste ◽  
Ground Rubber

In this paper, the blends of natural rubber with waste ground rubber powders have been prepared by mechano-chemical activation method. The influences of particle sizes on both processing performances and mechanical properties have been investigated. The results indicated that: the blends with waste ground rubber powders of smaller particle sizes approached to higher surface tensile and easily mechano-chemical activation, which led to the formation of complete homogenous re-vulcanization cross-linking structure and resulted in the improvements of the whole performances of the final products. The tensile strength, the elongation at break and tear strength approached to the highest value of 20.7MPa, 530% and 33.0 kN/m as the 100mesh waste ground rubber powders were used as the starting materials.

Effect of chain extender on the mechanical and thermal resistance properties of polyurethane liners for composite propellants

Polyurethanes ◽  
2016 ◽  
Vol 1 (1) ◽  
Author(s):  
P. Ross ◽  
G. Sevilla ◽  
J. Quagliano
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Thermal Properties ◽  
Chain Extender ◽  
Molecular Structures ◽  
Polymer Chains ◽  
Mechanical And Thermal Properties ◽  
Thermal Changes ◽  
Ft Ir ◽  
Chain Lengths

AbstractPolyurethane formulations utilized as liners for composite propellants were prepared by the reaction of toluene-2,4-diisocyanate (TDI) and isophorone diisocyanate (IPDI) with hydroxyl terminated polybutadiene (HTPB), while polymer chains were further extended with neopentyl glycol diol, NPG triol and two different triols (monoglyceryl ricinoleate, MRG and trimethylolpropane, TMP). Liners were formulated with micronized titanium dioxide mechanically dispersed in hydroxyl-terminated polybutadiene (HTPB). The molecular structures of liners were confirmed by FT-IR. Thermal properties indicated that the nature of chain extender (crosslinker) only slightly affected the temperatures for decomposition of liners. Two main thermal changes were found at 370∘C and another at around 440–500∘C, depending on the chain extender utilized. On the other side, mechanical properties varied within the range of 0,7-1,8 MPa, consistent with this kind of elastomers. Tensile strength at break was only significantly affected with TMP and MRG-chain extended liners at the lowest concentrations tested of 1,3 and 2% (w/w), respectively. However, the behaviour depended on whether TDI or IPDI isocyanate was utilized for curing. TMP 1,3% crosslinked liner cured with TDI had a tensile strength of 1,82MPa whileMRG-crosslinked liner cured with IPDI had a tensile strength of 1,56 MPa. It was observed that at the higher NCO/OH ratios essayed, tensile strength and hardness increased, improving mechanical properties. Our results confirmed that TMP and MRG triols together with NPG diols can be used to tailor mechanical and thermal properties of liners, considering their different hydroxyl functionalities and chain lengths.

Study on Mechanical Properties Aging of Spray Pure Polyurea for Hydraulic Concrete Protection

2011 ◽  
Vol 374-377 ◽  
pp. 1325-1329 ◽  
Author(s):  
Wei Bo Huang ◽  
Jia Yu Xiang ◽  
Ping Lv ◽  
Xin Mao Li
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Development Trend ◽  
Elongation At Break ◽  
Tear Strength ◽  
Hydraulic Concrete ◽  
Before And After ◽  
Ultraviolet Ray ◽  
Resistance Performance

Researches of spray pure polyurea technology for hydraulic concrete protection in water conservancy facilities to ensure long term security operation has a great significance. With an emphasis upon mechanical properties and surface morphology of spray pure polyurea coatings comparing before and after aging by means of the artificial accelerated xenon arc lamp(AAXAL) and scanning electron microscope(SEM) in this paper. Besides, the dry-wet circulation resistance performance of coatings wre analyzed through experiment. It is shown that tensile strength, elongation at break and tear strength of coatings increased by 0.2%, 0.5% and 1.7% respectively after AAXAL aging 720h. By contrast, after aging 3000h the results were 22.6%, 3.8% and 17.4% respectively, the tendency of increasing at first and then reducing can be obtained. The mechanical properties reduced slightly for adding defects of coating surface after aging, however, the resistance performance of ultraviolet ray was excellent. The similar development trend of mechanical properties were gained from dry-wet circulation experiment. After aging 200 cycles, the tensile strength and tear strength descended by 4.1% and 1.7% severally but the elongation at break ascended by 5.0%. In a word, it is suggested that the aging of coatings were negligible in dry-wet circulation in short term.

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