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Procuring silicone rubber composite with different content of vinyl MQ silicone resin was prepared and its thermal stability was evaluated. A total of 50 wt% MQ resin containing 5 wt% vinyl MQ exhibited optimal thermal stability and was consequently chosen. This silicone rubber composite was blended with TPU at high temperature using an internal mixer to produce a modified TPU. The TPU modified by silicone rubber was firstly investigated by Fourier Transform Infrared Spectroscopy (FTIR) and Thermogravimetric Analysis (TGA). The FTIR results indicated that negligible chemical reactions occurred between TPU and silicone rubber during the mixing process. Furthermore, the TGA results demonstrated that the silicone rubber composite positively influenced the thermal stability of TPU. Additionally, the modified TPU displayed satisfactory thermal stability even after aging. Moreover, Scanning Electron Microscope (SEM) results indicated that uniform dispersion of silicone rubber was facilitated by the banburying method. The tensile strength of modified TPU initially increased and then decreased when the content of silicone rubber reached 3 wt%. On the other hand, the elongation at break of modified TPU demonstrated continuous improvement. Furthermore, the mechanical properties of the modified TPU were still acceptable after aging. [ABSTRACT FROM AUTHOR]

Large-diameter polyvinyl alcohol (PVA) fiber has a broad application prospect in the field of reinforcing geomorphic building materials owing to its large diameter and excellent mechanical properties. In this work, PVA2499 polymer was used as the raw material, DMSO/H2O as the hybrid solvent, and the staged heating approach was adopted to obtain high solid content of spinning solutions, and then a series of large-diameter medium-strength PVA fibers with different solid contents of spinning solutions (SCS) were prepared by dry-wet spinning, and the Fourier transform infrared spectroscopy (FTIR), scan electron microscope (SEM), differential scanning calorimetry (DSC), thermal analysis (TGA), X-ray diffractometer (XRD) and electronic universal testing machine were performed to explore the effect of the SCS on the structure and performance of PVA fiber. The results displayed that with the increase of the SCS, the -OH stretching vibration absorption peak of PVA fiber moved from 3276 cm−1 to 3262 cm−1; The tensile strength, initial modulus, the crystallization and orientation of PVA fibers all increased first and then decreased. Especially, when the SCS was 23.5wt%, the diameter of the PVA fiber was 110.6 ± 6.0 μm (124.8 ± 6.2 dtex), the tensile strength was 7.0 ± 0.3 cN/dtex, the initial modulus was 106.2 ± 10.3 cN/dtex, the crystallization and the orientation were 49.6% and 96.8%, respectively. [ABSTRACT FROM AUTHOR]

Two kinds of porous hollow glass microsphere (HGM) were synthesized using HGM as a raw material. Then, silicone rubber (SR) based composites with porous HGM as inorganic filler were prepared. The microstructures of the composites were characterized by a scanning electron microscope (SEM), and the relationship between the interface structure and strengthening mechanism was explained. Due to the formation of interpenetrating networks through SR chains inserting into porous HGM, the interfacial adhesion was enhanced. Therefore, tensile strength and elongation at break of SR were greatly improved by porous HGM. Especially for HGM-2 with high specific surface area and through-hole, tensile strength of SR/HGM-2 composite with only 2 phr HGM-2 increased from 0.41 MPa to 0.91 MPa, and elongation at break increased from 103 to 251%. The densities of composites with filler content ranging from 2 phr to 15 phr were also examined. Particularly, the density of SR/HGM-1 composite with 15 phr HGM-1 further decreased to 0.75 g/cm3 compared with that of SR/HGM (0.82 g/cm3). In addition, the thermal stability of SR composites with porous HGM was also significantly improved. Along with through-hole structure of HGM-2, another straightforward consequence of SR/HGM-2 composite was high transparency caused by reduction of light scattering. [ABSTRACT FROM AUTHOR]

Fluorine rubber (FKM) is often used in bearing seals, bearing seal will be affected by high temperature in the process of use and performance decline. Therefore, in this paper, the effect of CeO2 on the high temperature composite properties of FKM was studied by filling CeO2 nanoparticles into FKM. 5% CeO2/FKM composites were prepared by mechanical blending and hot-pressing process after nano CeO2 was treated with silane coupling agent KH-570. After mechanical and high temperature friction tests of CeO2/FKM composites, the morphology of CeO2/FKM composites was characterized by three-dimensional topography instrument and scanning electron microscope. The mechanical strengthening mechanism and anti-wear and anti-friction mechanism of CeO2 on FKM were expounded. The results showed that the microstructure of Fluor elastomer with CeO2 particles was reinforced, and the defects of fluorine rubber itself were filled. Specifically, compared with the original FKM, the strength of CeO2/FKM composite was improved, in which the tensile strength reached 20.75 MPa, increased by 18.5%, and the tear strength reached 43.44 N/mm, increased by 3.5%. CeO2/FKM composites show outstanding anti-wear and low friction coefficient properties at high temperature (200 °C). The main mechanism is that nano-CeO2 keeps high hardness of FKM, and CeO2/FKM composites have high crosslinking density. [ABSTRACT FROM AUTHOR]

Present work explores the utilization of forest waste (pine cone) and plastic waste (recycled HDPE) to fabricate wood plastic composites (WPCs) using microwave-assisted compression molding. The developed WPCs were experimentally subjected to physical, thermal, and mechanical characterization. Physical properties deteriorated when the filler loading level was maximized over the weight percentages due to poor wettability. The thermal study revealed that the melting point of the composites was influenced by filler weight percentage. The composites reinforced with 20 Wt.% filler exhibited the highest tensile, flexural, and impact strength of 20.01 MPa, 20.98 MPa, and 15.79 kJ/m2, respectively. Scanning electron microscope (SEM) micrographs revealed voids, microcracks, and poor filler dispersion were dominantly responsible for composites failure with increased filler weight fraction. [ABSTRACT FROM AUTHOR]

Cyanogen functionalized carbon nanotube and graphene/poly (arylene ether nitrile) (CNT-CN/GN-CN/PEN) nanocomposite films were prepared by a facile solution casting method. The weight ratio of CNT-CN/GN-CN was varied from CNT-dominated to GN-dominated for the purpose of investigating their synergetic effects on the mechanical and thermal properties of PEN nanocomposites. Consequently, GN-CN/PEN composites demonstrated better mechanical and thermal properties than CNT-CN/PEN composites due to larger contact area between GN-CN and PEN matrix. Nevertheless, all CNT-CN/GN-CN/PEN composites exhibit enhanced mechanical properties than those of GN-only nanocomposites. With the increasing of CNT-CN/GN-CN weight ratio, the mechanical properties of CNT-CN/GN-CN/PEN composites increase, then decrease, and reach their maximums when CNT-CN/GN-CN weight ratio is around 4/4. From scanning electron microscope images, it is found that around that point GN-CN is flatly dispersed and CNT-CN is penetrated into GN-CN, capable of transferring stress load and thus decreasing interface loss. Thermal properties of CNT-CN/GN-CN/PEN composites once again confirmed the joint effect of CNT-CN and GN-CN, leading to improved thermal properties. In short, a synergistic effect between one-dimensional (1-D) CNT and two-dimensional (2-D) GN on the mechanical and thermal properties of nanocomposites have been demonstrated in these systems. [ABSTRACT FROM AUTHOR]

A biodegradable elastomer (PLCA/PLGA blends) was prepared and characterized. First, poly(DL-lactide-co-ε-caprolactone) (PLCA) and poly(DL-lactide-co-glycolide) (PLGA) were synthesized. Infrared (IR) spectroscopy, 1H nuclear magnetic resonance (NMR), and gel permeation chromatography (GPC) were used to confirm the formation and structure of PLCA and PLGA. The solubility parameters of PLCA and PLGA were measured to estimate the miscibility between them. A series of PLCA/PLGA blends was prepared through solution blending. The morphology of all blends was examined by scanning electron microscope (SEM), and no obvious phase separation was detected at various ratios of PCLA and PLGA. Thermomechanical properties were characterized using thermogravimetry (TG), differential scanning calorimetry (DSC), and dynamic mechanical analysis (DMA), the results showed that the PLCA/PLGA blends were a type of immiscible but compatible polymer blend. Mechanical properties, particularly stress-strain behavior, were examined; with an increase in PLGA content, the tensile strength and Young’s modulus of the blends increased dramatically, while elongation at break decreased. [ABSTRACT FROM AUTHOR]

A graft copolymer composed of poly (2-hydroxy ethyl acrylate) (PHEA) as branched chains and chlorinated polyethylene (CPE) as backbone, CPE- cg-HEA, was synthesized by in situ chlorinating graft copolymerization (ISCGC). The polymer has special molecular structure with short graft chains and abundant branched points. The mechanical properties of CPE- cg-HEA were studied by tensile testing, differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA). The morphologies of tensile fractured surfaces for CPE and CPE- cg-HEA were investigated by scanning electron microscope (SEM). The testing results indicated the mechanical properties of the in situ chlorinating graft copolymers have greatly improved compared with CPE with about the same chlorine content. Particularly, there was a broad plateau on the stress–strain curve of the graft copolymer, which meant a high elastic-like deformation. [ABSTRACT FROM AUTHOR]

The biodegradation is becoming one of the most imperative properties of plastic products nowadays to promote the sustainable development and the conservation of the environment. In this framework, the main objectives of this study are to prepare an environmental friendly high density polyethylene (HDPE) nanocomposite and investigate the effect of the incorporation of nanoparticles of calcium carbonate (NPCC) and poly butylene succinate (PBS) on the prepared nanocomposites. The nanocomposites of HDPE/PBS/NPCC samples were prepared by the addition of PBS and NPCC at (1, 2 and 4 wt%) to HDPE matrix using the injection molding technique. Morphological, mechanical, thermal, physical and biodegradation analysis were conducted on the nanocomposite samples. The mechanical properties of the samples were improved (the elongation at break by 35%, and the impact strength by 26%) compared to the neat HDPE. Moreover, the thermal and physical properties were enhanced by reinforcement NPCC to the nanocomposites. The biodegradation occurrence in the HDPE nanocomposite samples was proved by the Scanning Electron Microscope (SEM) observations and the weight loss percentage (0.265 wt% after 8 weeks). [ABSTRACT FROM AUTHOR]

A comprehensive and comparative experimental study has been conducted to investigate the effect of thermal-oil ageing on mechanical, thermal and internal structural properties of E-glass fibre/epoxy composite materials. E-glass fibre/epoxy composite specimens were divided into 8 groups according to the certain experimental ageing temperatures. The temperature values were selected as −10, 25, 50, 80, 100, 120 and 140 °C, while the values of the ageing duration were selected as 24, 168, 360, 720 and 1080 h. Thermogravimetric Analysis (TGA) and Differential Thermal Analysis (DTA) tests were performed to determine the thermal properties, tensile tests were used to detect the mechanical properties and a Scanning Electron Microscope (SEM) was used to illustrate the changes in the internal structure of the composites. As a result of this work, unexpectedly no alteration was observed in the mechanical properties of the specimens aged at −10 °C; however, ageing at 120 and 140 °C reduced the maximum load carrying capacities (LCCs) of the specimens especially for further ageing exposure times. Furthermore, the thermal stability of the specimens aged at −10 °C increased with the increasing thermal ageing duration while, for the other thermal ageing temperatures, the thermal stability showed a decreasing trend as the thermal ageing exposure time increased. [ABSTRACT FROM AUTHOR]

Natural fiber composite laminates are nowadays used in structural application such as aerospace, automobile and in sports goods because of their high strength to weight ratio and renewability. Hence the study of mechanical behaviors of natural fiber composites is very important in using these composite laminates for such specific applications. This project aims at identifying the mechanical properties of hybrid natural Jute/Kenaf fiber. The major drawbacks in natural fiber are its Resin incompatibility. Surface treatment of fiber is made to improve the interfacial bonding between the fiber and resin and to reduce the moisture absorption. Laminates are fabricated using Hand lay-up technique. Mechanical properties such as tensile, flexural, and Impact test for jute/kenaf hybrid laminates were obtained. Specimen preparation and Mechanical property testing were carried out as per ASTM standards. Micro structures of the different layer of hybrid specimens are scanned by the Scanning Electron Microscope. [ABSTRACT FROM AUTHOR]