scholarly journals Cross-Linkable Epoxidized Maleinated Castor Oil: A Renewable Resin Alternative to Unsaturated Polyesters

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Yeşim Müge Şahin ◽  
Gökhan Çaylı ◽  
Jesmi Çavuşoğlu ◽  
Emre Tekay ◽  
Sinan Şen
Keyword(s):  
Mechanical Properties ◽  
Castor Oil ◽  
Unsaturated Polyester ◽  
Mechanical Analysis ◽  
Carboxyl Groups ◽  
Spectroscopic Techniques ◽  
Thermal And Mechanical Properties ◽  
Unsaturated Polyesters ◽  
H Nmr ◽  
And Storage

As an alternative resin to conventional synthetic unsaturated polyesters (UPEs), epoxidized maleinated castor oil (EMACO) was synthesized in two steps. For this purpose, castor oil was reacted with maleic anhydride at 70°C to obtain maleinated castor oil (MACO). Then, epoxidation of MACO was carried out by using a mixture of formic acid and hydrogen peroxide at 0–5°C. Then, the free carboxyl groups of the synthesized EMACO were further reacted with free epoxide groups of EMACO at 90°C. At the end of the reaction, an unsaturated polyester precursor-prepolymer was obtained (P-EMACO). FTIR and1H NMR spectroscopic techniques were used to characterize the monomers synthesized. The P-EMACO was then mixed with styrene and cross-linked in the presence of AIBN at 50°C. Thermal and mechanical properties of the final cross-linked product were investigated by thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA) techniques. The degradation onset temperature of the material at which cross-linked X-EMACO loses 5% of its weight was found to be 209°C. Its dynamicTgand storage modulus at 25°C were determined as 72°C and 1.08 GPa, respectively. These results are higher than some of the different oil based polymers reported in the literature.

Effect of Carbon Nanotube on Electrical, Thermal and Mechanical Properties of Epoxy

2007 ◽  
Author(s):  
Yuanxin Zhou ◽  
Peixuan Wu ◽  
Zhongyang Cheng ◽  
Biddut Kanti Dey ◽  
Shaik Jeelani
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Carbon Nanotube ◽  
High Speed ◽  
Mechanical Test ◽  
High Vacuum ◽  
Mechanical Analysis ◽  
Thermal And Mechanical Properties ◽  
Multi Walled Carbon Nanotubes ◽  
Mechanical Agitator

In this study, electrical, thermal and mechanical properties of multi-walled carbon nanotubes (CNTs) reinforced Epon 862 epoxy have been evaluated. Firstly, 0.1 wt%, 0.2 wt%, 0.3 wt%, and 0.4 wt% CNT were infused into epoxy through a high intensity ultrasonic liquid processor and then mixed with EpiCure curing agent W using a high speed mechanical agitator. The trapped air and reaction volatiles were removed from the mixture using a high vacuum. Neat epoxy sample also was made as reference. Electrical conductivity, dynamic mechanical analysis (DMA, three point bending tests and fracture tests were performed on unfilled, CNT-filled epoxy to identify the loading effect on the properties of composites. Experimental results show significant improvement in electric conductivity. The resistivity of epoxy decreased to 15Ωm with 0.4% CNT. DMA studies revealed that filling the carbon nanotube into epoxy can produce a 90% enhancement in storage modulus and a 17° C increase in Tg, but CNT has little effect on decomposing temperature. Mechanical test results showed that modulus increased with higher CNT loading percentages, but the 0.3 wt% CNT-infusion system showed the maximum strength and fracture toughness enhancement. The decrease in strength and fracture toughness in 0.4% CNT/epoxy was attributed to poor dispersions of nanotubes in the composite.

Thermal and Mechanical Properties of Cyclized Polybutadiene Dielectrics

1986 ◽  
Vol 76 ◽  
Author(s):  
C. W. Wilkins ◽  
H. E. Bair ◽  
M. G. Chan ◽  
R. S. Hutton
Keyword(s):  
Mechanical Properties ◽  
Differential Scanning Calorimetry ◽  
Physical And Mechanical Properties ◽  
Mechanical Analysis ◽  
Infrared Analysis ◽  
Thermal And Mechanical Properties ◽  
Scanning Calorimetry ◽  
The Difference ◽  
Thermal Mechanical Analysis ◽  
Lower Glass Transition Temperature

ABSTRACTWe have studied some of the physical and mechanical properties of cyclized polybutadiene (CBR) dielectrics by dynamic mechanical analysis, thermal mechanical analysis, thermogravimetry, infrared analysis, and differential scanning calorimetry. Of interest is the difference in properties between thin (<30 μm) films which have been cured under vacuum and those which have been cured in air. Our results indicate that curing under vacuum prevents oxidation and reduces crosslinking. Vacuum cured films have 20% smaller moduli and 200 lower glass transition temperature than do films produced in air.

Mechanical and Thermal Properties of Carbon-Nanofiber Infused Polyurethane Foam

2008 ◽  
Author(s):  
Md. Atiqur Bhuiyan ◽  
Mahesh V. Hosur ◽  
Yaseen Farooq ◽  
Shaik Jeelani
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanofibers ◽  
Polyurethane Foam ◽  
High Speed ◽  
Carbon Nanofiber ◽  
Mechanical Analysis ◽  
Mechanical And Thermal Properties ◽  
Diphenylmethane Diisocyanate ◽  
Thermal And Mechanical Properties ◽  
Mechanical Agitator

In this study, thermal and mechanical properties of carbon nanofiber infused polyurethane foam were investigated. Low density liquid polyurethane foam composed of Diphenylmethane Diisocyanate (Part A) and Polyol (Part B) was doped with carbon nanofibers (CNF). A high-intensity ultrasonic liquid processor was used to obtain a homogeneous mixture of Diphenylmethane Diisocyanate (Part A) and carbon nanofibers (CNF). The CNF were infused into the Part A of the polyurethane foam through sonic cavitation. The modified foams containing nanoparticles were mixed with Part B (Polyol) using a high-speed mechanical agitator. The mixture was then cast into pre-heated rectangular aluminum molds to form the nano-phased foam panels. Flexure, static and high strain rate compression, and dynamic mechanical analysis (DMA) were performed on neat, 0.2 wt%, 0.4 wt% and 0.6 wt% CNF filled polyurethane foam to identify the effect of adding CNF on the thermal and mechanical properties. The highest improvement on thermal and mechanical properties was obtained with 0.2 wt% loading of CNF. Morphology of the samples was studied through X-ray diffraction.

Study on Thermal and Mechanical Properties of Natural Rubber Latex Modified by Trichlorobromomethane

2011 ◽  
Vol 295-297 ◽  
pp. 36-40
Author(s):  
Xiao Xue Liao ◽  
Shuang Quan Liao ◽  
Bing Tang ◽  
Ming Chao Luo ◽  
Yan Fang Zhao ◽  
...  
Keyword(s):  
Natural Rubber ◽  
Storage Modulus ◽  
Loss Modulus ◽  
Natural Rubber Latex ◽  
Mechanical Analysis ◽  
Thermal And Mechanical Properties ◽  
Rubber Latex ◽  
Scanning Calorimetry ◽  
And Storage ◽  
Thermal Stability Of

Natural rubber latex (NRL) modified by holgonated addition with trichlorobromomethane was prepared. The thermal properties of modified NRL were analyzed by thermogravimetric analysis (TG/DTG),differential scanning calorimetry (DSC) and dynamic mechanical analysis(DMA). The results showed that the thermal stability of modified NRL was lower than NRL and the thermal degradation of modified NRL was two-stage decomposition. With increasing of stress frequency, loss modulus and storage modulus of latex increased,while loss modulus and storage modulus of modified latex decreased,compared with NRL.

scholarly journals The Effects of Epoxidized Acrylated Castor Oil (EACO) on Soft Poly (vinyl chloride) Films as a Main Plasticizer

2018 ◽  
Vol 20 (4) ◽  
pp. 13-19 ◽  
Author(s):  
Fei Song ◽  
Haoyu Xia ◽  
Puyou Jia ◽  
Meng Zhang ◽  
Lihong Hu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Hydrogen Peroxide ◽  
Solvent Extraction ◽  
Castor Oil ◽  
Second Step ◽  
H Nmr ◽  
Plasticized Pvc ◽  
Poly Vinyl Chloride ◽  
Nmr Techniques

Abstract In this work, an environmentally friendly type plasticizer was introduced. The synthesis consisted of two steps. In the first step, castor oil (CO) was acrylated and then the acrylated castor oil (ACO) was epoxidized with the presence of formic acid and hydrogen peroxide in the second step. The epoxidized acrylated castor oil (EACO) was characterized by FTIR and 1H-NMR techniques. The EACO was used as a main plasticizer to obtain plasticized PVC materials and compared with DOP. The results showed that EACO improved polyvinyl-chloride (PVC) plasticization performance and reduced Tg from 81.06°C to 1.40°C. Plasticized PVC materials with EACO showed similar mechanical properties and better thermal stability than DOP. EACO had better volatility stabilities, migration and solvent extraction in PVC than DOP. EACO can be used to replace DOP to prepare soft films.

scholarly journals Improvement of Thermal and Mechanical Properties of Vietnam Deproteinized Natural Rubber via Graft Copolymerization with Methyl Methacrylate

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Thi Nhan Nguyen ◽  
Hieu Nguyen Duy ◽  
Dung Tran Anh ◽  
Thuong Nghiem Thi ◽  
Thu Ha Nguyen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Natural Rubber ◽  
Methyl Methacrylate ◽  
Graft Copolymer ◽  
Graft Copolymerization ◽  
Graft Copolymers ◽  
Thermal And Mechanical Properties ◽  
H Nmr ◽  
Tert Butyl Hydroperoxide ◽  
Deproteinized Natural Rubber

In this study, we investigated the improvement of the thermal and mechanical properties of Vietnam deproteinized natural rubber (DPNR) via graft copolymerization of methyl methacrylate (MMA). The graft copolymerization was achieved successfully in latex stage using tert-butyl hydroperoxide (TBHPO) and tetra-ethylenepentamine (TEPA) as radical initiators at 30°C. By grafting with various MMA feeds and initiator concentration of 6.6×10−5 mol/g-rubber, the highest grafting efficiency and conversion were achieved at MMA of 15 wt.% per kg of rubber, 68% and 90%, respectively. The structure of grafted copolymers was characterized by 1H NMR, FTIR-ATR, and GPC, and thermal properties were investigated through DSC and TGA measurements. These showed that graft copolymers were more stable and rigid than DPNR. Storage modulus (G′) of graft copolymer was found to double that of DPNR, which contributed to the formation of graft copolymer. After sulfur vulcanization, the mechanical properties of DPNR-graft-PMMA, such as tensile strength, tear strength, and hardness, were improved significantly. Curing behaviors of the graft copolymers were found to be remarkably better than virgin DPNR.

Synergistic effect of carbon nanotubes and nano-hydroxyapatite on mechanical properties of polyetheretherketone based hybrid nanocomposites

2020 ◽  
pp. 096739112096950
Author(s):  
Manjeet Kumar ◽  
Rajesh Kumar ◽  
Sandeep Kumar
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Elastic Modulus ◽  
Storage Modulus ◽  
Fracture Resistance ◽  
Compression Molding ◽  
Mechanical Analysis ◽  
Hybrid Nanocomposites ◽  
Hybrid Nanocomposite ◽  
And Storage

Hybrid nanocomposites utilize the benefits of properties of different fillers to enhance its desired properties. Polyetheretherketone (PEEK) based hybrid nanocomposites have immense potential applications in aerospace, automobile, high-temperature electrical applications, and medical and health care. The present work is an attempt to improve the elastic modulus, hardness, fracture resistance, and storage modulus simultaneously by reinforcing the PEEK matrix with multiwall carbon nanotubes (MWCNTs) filler and 30 wt.% nano hydroxyapatite (nHA)-MWCNT hybrid filler. The nanocomposites having 0,1,3,5 and 7 wt.% of MWCNTs were fabricated by the Ball Mixing and Compression Molding Method. Customized Die Heater setup was used to ensure uniform heating and cooling during compression molding. The morphology was examined by Field Emission Scanning Electron Microscopy (FESEM) and Energy-Dispersive X-ray Spectroscopy (EDS) and uniform distribution of nano-fillers was observed. The nanoindentation method was adopted to investigate the Static Mechanical Analysis (SMA) and Dynamic Mechanical Analysis (DMA) at varying frequencies of loading, of nanocomposites. At 5 wt.% of MWCNTs, the enhancements in elastic modulus, hardness, fracture resistance, and storage modulus were observed to be 80%, 36%, 32%, and 58% respectively in case of PEEK/(0–7%)MWCNT nanocomposite and 104%, 76%, 16%, and 80% respectively in case of PEEK/30%nHA-(0–7%)MWCNT hybrid nanocomposite. The decrements in loss factor indicated the improvement in elastic behavior of nanocomposites with increasing wt.% of MWCNTs. The elastic modulus of PEEK/30%nHA-5%MWCNT hybrid nanocomposite was observed to be 7.67 GPa, which falls within the range of elastic modulus of the human cortical bone. The results revealed that 5 wt.% of MWCNTs is optimum filler composition for improving the mechanical properties.

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