Addition Of Epoxidized Natural Rubber Research Articles

Effect of Electrospinning Parameters on the Morphological and Thermal Properties of ABS/ENR Electrospun Fibres

The electrospun of the Acrylonitrile-butadiene-styrene (ABS) blend with epoxidized natural rubber (ENR) is fabricated using the electrospinning technique. Research shows that ABS/ENR electrospun fibres have not been studied. The effects of electrospinning parameters were investigated to determine a significant effect on the microstructure, surface roughness, fibre diameter, and fibre distribution of the electrospun membranes. Sample preparation is made straightforwardly by dissolving ABS and ENR in acetone solvent using a magnetic stirrer. In this research, there are two solution parameters being studied: the ABS/ENR solution concentration (15 to 25 wt.%) and the ratio of ENR (100:0, 70:30, 50:50). Meanwhile, process parameters that are being studied are applied voltage (15 kV to 30 kV) and distance from syringe tip to collector (5cm to 15cm). FTIR results showed that hydrogen bond interaction occurs between ABS and ENR. According to the SEM images, micrometre and sub-micrometre fibres with a smooth surface and bead formation were produced at a concentration of 25%, a ratio of 70:30, a voltage of 30kV, and a distance of 15cm. The diameter of electrospun fibres increases with increasing solution concentration, ranging from 400 nm to 4.5 µm. The diameter of the electrospun fibres decreased with the addition of ENR, increasing voltage, and tip-to-collector distance. TGA results showed that ABS/ENR blends gave higher degradation temperature (393.7°C) than pure ABS (368.8°C), which enhanced thermal stability.

Thermoplastic mung bean starch/natural rubber/sericin blends for improved oil resistance

Oil resistant thermoplastic elastomers (TPE) were prepared using mung bean thermoplastic starch (MTPS) blending with rubbers and sericin. Sericin was incorporated into MTPS as a compatibilizer. MTPS with sericin (MTPSS) was blended with natural rubber (NR) and epoxidized NR (ENR). Sericin at 5% improved the tensile strength (10 MPa), elastic recovery (52%) and morphology of the MTPSS/ENR blend. The mechanical properties, elastic recovery and morphology of the MTPSS5/NR blend were improved by the addition of ENR. The MTPSS/ENR showed palm (28%) and motor oils (8%) swelling resistance because of the hydrophilicity of MTPS and high polarity of ENR. The MTPSS/ENR/NR showed gasoline swelling resistance (104%) because of the hydrophilicity of MTPS and low polarity of NR. FTIR confirmed a reaction between the –NH groups of sericin and the epoxy groups of ENR. This reaction improved the compatibility, mechanical properties, elastic recovery, morphology and oils swelling resistance of the blends.

Improved Viscoelastic Damping Properties of Carbon Black Reinforced EPDM Composites by Blending with ENR

EPDM/ENR blends were prepared from saturated nonpolar ethylene propylene diene monomer (EPDM) and unsaturated epoxidized natural rubber (ENR). The dynamic mechanical properties of EPDM/ENR compounds and their vulcanizates were studied by rubber processing analyzer and dynamic mechanical thermal analyzer. The results show that the addition of ENR is helpful to improve EPDM processability. With the increase of ENR content, the tensile strength of EPDM/ENR decreases first and then increases while the elongation at break increases. The lowest tensile strength is still greater than 12.5MPa, which shows the industrial usage. The temperature range for the loss factor being greater than 0.1 becomes wider from -40.1 ˚C ~ 7.7 ˚C for pure EPDM to -40.1 ˚C ~ 80 ˚C for 80 : 20 EPDM/ENR.

Unidirectional Rubber-Toughened Green Composites based on PHBV

The large-scale entry of bio-based polymers, such as poly(hydroxybutyrate-co-valerate) (PHBV), in applications commonly occupied by petroleum-based plastics is heavily limited by their poorer mechanical properties, thus, hindering efforts to reduce harmful plastic waste. Prior work to improve these properties has involved short natural fibre reinforcements, which do not produce substantial improvements. In this work, PHBV was simultaneously reinforced with unidirectional flax and toughened with poly(butylene adipate-co-terephthalate) (PBAT) or epoxidized natural rubber (ENR) to produce well-rounded composites. Toughened unidirectional composites were prepared by cryogenic grinding, powder layup and compression moulding. Unidirectional flax addition resulted in 4-fold increases in tensile properties, 3-fold increases in flexural properties and 20-fold increases in impact properties, whilst producing minimal change in the thermal properties. PBAT and ENR phases appeared well bonded to the PHBV within the composite. The addition of PBAT did not cause any significant changes in thermal or mechanical properties. The addition of ENR, however, reduced the tensile modulus and the flexural properties but produced a significant increase in impact strength, attributed to the coarse particle size of ENR. Unidirectional flax reinforcement of PHBV widens the scope of application of PHBV considerably where mechanical properties are of concern, while ENR has significant potential as a bio-based toughening agent for biocomposites.

Development of Biobased Poly(Lactic Acid)/Epoxidized Natural Rubber Blends Processed by Electrospinning: Morphological, Structural and Thermal Properties

This article reports the production of electrospun fibers from blends of poly(lactic acid) (PLA) and epoxidized natural rubber (ENR) solutions. The produced fibers were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA). SEM images showed the reduction in fiber size with ENR content of up to 25% in the mixture PLA/ENR. FTIR analysis revealed a possible interaction between carboxylic group of PLA and epoxi group of ENR. Thermal analysis showed the increase of the crystallinity fraction with ENR content and a decrease in thermal stability of eletrospun mats with the addition of ENR. The dynamic mechanical properties showed an enhancement of the stiffness of PLA/ENR blends with the increase of ENR content, which can support the production of interesting materials for tissue engineering based on renewable and biocompatible polymers. The reported properties indicate the possibility to use such fiber mats as potential materials in tissue engineering.

MECHANICAL PERFORMANCE OF MODIFIED EPOXY REINFORCED HYBRID NATURAL FIBER COMPOSITE

Kenaf fiber that is known as Hibiscus cannabinus, L. family Malvaceae is an herbaceous plant that can be grown under a wide range of weather conditions. The usage of kenaf fibers as a reinforcement material in the polymeric matrix has been widely investigated. In this research, liquid epoxidized natural rubber (LENR) was introduced to the epoxy to increase its toughness. Hybrid kenaf/carbon fibers, with different kenaf/carbon ratio weight, were used to reinforce the epoxy resins (with and without addition of epoxidized natural rubber) as the matrices. The flexural strength, flexural modulus and fracture toughness of the rubber toughened epoxy reinforced hybrid kenaf/carbon fiber composites were investigated. The results showed that the addition of liquid epoxidized natural rubber (LENR) had improved the flexural strength, flexural modulus and fracture toughness by 9.6%, 13.7%, and less 2% respectively at the ratio of 16:4 wt% fibre loading

Silica-reinforced tire tread compounds compatibilized by using epoxidized natural rubber

Silica-reinforced natural rubber (NR) tire tread compounds with epoxidized natural rubber (ENR) as a compatibilizer are investigated. The ENRs consisting of 10, 38 and 51mole% epoxide are used in a range of 2.5–15.0 parts per hundred parts of rubber (phr). The addition of ENRs, especially ENR-38 and ENR-51, decreases the Mooney viscosity, Payne effect, flocculation rate constant and filler networking factor, which implies an improvement of silica dispersion in the compounds. Chemically bound rubber contents and interaction parameters of the compounds also increase with higher epoxide-contents of the ENRs, indicating more interactions and/or reaction between the epoxide-groups of the ENR and silanol groups on the silica surface. Tensile strength of the vulcanizates is improved with increasing mole% epoxide, and the optimum value is observed at 7.5phr of ENR-51. The overall results show that silica-reinforced NR can be substantially improved by adding ENR as a compatibilizer, when compared to a compound without ENR, but somewhat less than with using a silane coupling agent.

Thermal and Mechanical Properties of Mulch Film from Poly(Lactic Acid)/Expoxidized Natural Rubber Blends Filled with Rutile TiO<sub>2</sub> as Fillers

The aim of this research was to reduce and improve the brittleness and thermal properties of poly lactic acid (PLA), respectively. Epoxidized natural rubber (ENR) was used to enhance the toughness and rutile titanium dioxide (R-TiO2) as filler was also incorporated to improve the thermal properties of the PLA. 10wt% ENR with epoxidation contents of 25 mol% (ENR25) and 50 mol% (ENR50) and various R-TiO2contents (0-10 phr)were compounded with PLA by using a twin-screw extruder at 155-165°C and a rotor speed of 40 rpm. The pellets of blends were then formed a thin film using a cast film extruder machine and cooled down under air flow. Thermal and mechanical properties and morphology of PLA/ENR/R-TiO2thin film were investigated. The crystallinity of PLA was found to increase with addition of ENR. The mechanical properties of thin film showed that the ENR50 enhanced the elongation but reduced the tensile strength of PLA with addition of R-TiO2at 5 and 10 phr, respectively. The TGA indicated that the addition of 10 phr R-TiO2increased in the decomposition temperature at 5% weight loss (Td5%) of PLA/ENR film. Thus the thermal stability of PLA/ENR50 was found to improve with addition of R-TiO2. From morphology study, the ENR50 phase showed a good dispersion in the PLA matrix. In conclusion, the addition of ENR and R-TiO2was found to enhance both toughness and thermal stability of PLA.

Epoxidized natural rubber toughened polyamide 6/organically modified montmorillonite nanocomposites

The organically modified montmorillonite (OMMT)-filled polyamide 6 (PA6) nanocomposites were toughened with epoxidized natural rubber (ENR). The PA6, ENR (15–30 wt%) and OMMT (4 parts per hundered (phr)) were melt compounded using counterrotating twin-screw extruder followed by the injection molding. X-ray diffraction (XRD) results indicated that the OMMT platelets in PA6/ENR/OMMT nanocomposites were well dispersed. The Fourier transform infrared (FT-IR) spectra showed graft esterification reaction between PA6 and ENR during processing. It was found that the addition of ENR (up to 20% wt) increased the impact strength and elongation at break of the nanocomposites. Scanning electron microscopy (SEM) images revealed well-dispersed ENR particles. Differential scanning calorimetry (DSC) results showed that the presence of ENR and OMMT had negligible effect on the glass transition of PA6 with a slight decrease in crystallization temperature and crystallinity in PA6/ENR/OMMT nanocomposites.

Properties of solid solutions of poly(ethylene oxide)/epoxidized natural rubber blends and LiClO4

AbstractSolid solutions of blends of poly(ethylene oxide) (PEO) and epoxidized natural rubber (ENR) comprising 12 wt % of LiClO4 were studied. Two glass transition temperatures, corresponding to the Tgs of the constituents, confirm immiscibility of the polymers over the entire composition range. It turns out that the Tgs of both polymers slightly increase after addition of salt to the blends. This shift is approximately constant over the whole range of blend composition. Accordingly, Tg measurements reveal that the salt dissolves to approximately equal relative amounts in the two phases. The degree of crystallinity of PEO in blends with ENR descends only to a minor extent with ENR content. However, addition of salt leads first to decreasing crystallinity and second this decrease becomes more pronounced with the addition of ENR. It shows that under these experimental conditions the salt content in PEO increases as compared to ENR. As one expects, the rate of isothermal crystallization does not change in blends as long as PEO is in excess. The situation changes again when salt is added. The rate decreases in a certain range of crystallization temperatures when ENR is added, demonstrating that salt is favorably dissolved in PEO. Conductivity was measured in polymers comprising different salt concentrations. A power‐law dependence of conductivity on salt concentration was found. It results that the mobility of charge carriers in PEO exceeds that of ENR by five orders of magnitude. Therefore, the conductivity in blends is primarily governed by PEO as long as PEO is in excess. Conductivity measurements reveal again that salt is preferably dissolved in PEO. The distribution coefficient is estimated. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

Improving adhesion properties between rubber compound and brass-plated steel cord by the addition of epoxidized natural rubber to rubber compound

The adhesion between a rubber compound containing epoxidized natural rubber (ENR) and a brassplated steel cord was studied to shed light on the role of ENR for the improvement of adhesion. The addition of ENR in the rubber compound caused cure rate to decrease, and as ENR loading increased, modulus and hardness increased while tensile strength and elongation at break decreased. An improvement of adhesion was obvious with low loading of ENR at the range of 2 phr, while an adverse effect was observed with higher concentrations of 10 phr. Since the ratio of sulfur to copper at the interphase of the rubber compound/brass film adhesion sample increases with increased ENR loading up to 2 phr, the acceleration of sulfide formation by ENR could be proven. Adequate curing of rubber and the formation of high-molecular layer at the interphase by addition of small amount of ENR improve adhesion. However, the toughening of the rubber caused by the addition of larger amounts of ENR degrades the adhesion due to the poor physical properties of the rubber compound.