Natural Rubber Powder Research Articles

An Experimental Study of the Properties of Carbon Fiber/Epoxy Composites Mixed with Rubber Granules

In this research work, the mechanical properties of hybrid composites reinforced with woven carbon fiber mats particulated with natural rubber powders as fillers in the epoxy resin matrix were investigated. The specimens were prepared by the hand-layup process followed by a vacuum bag moulding process. The vacuum moulding reduces the voids or cavities in the hybrid composites. The natural rubber powder was added in different weight proportions (5%, 10%, 15%, and 20%), and carbon fiber is added in 20% for all the specimens. Experiments such as tension testing, flexural testing, water absorption/acid corrosion/base corrosion tests, dynamic mechanical analysis (DMA), and scanning electron microscopic (SEM) analysis were conducted to evaluate the epoxy carbon rubber (ECR) composites. The tensile and flexural test findings demonstrated that the addition of 10% natural rubber particles gave better results as compared with other proportions. The water/acid/base absorption test findings reveal that the ECR composites are not affected by water/acid/base. The DMA teat findings show that ECR composites having 10% natural rubber have higher damping factor, storage, and loss modulus. The SEM analysis shows that ECR hybrid composites with 10% rubber particles contained a uniform distribution of rubber particles over reinforcement, and also, there were no cracks and voids. According to this research findings, ECR hybrid composites with 10% natural rubber particles prepared during the vacuum bag moulding process can be used to prepare aerospace interior components.

Eco-Friendly Degradation of Natural Rubber Powder Waste Using Some Microorganisms with Focus on Antioxidant and Antibacterial Activities of Biodegraded Rubber

Natural rubber (NR) powder wastes contribute to the pollution of the environment and pose a risk to human health. Therefore, Escherichia coli AY1 and Aspergillus oryzae were used to degrade NR in the present investigation. The biodegradation was further confirmed using E. coli AY1 and A. oryzae’s ability to create biofilm, which grew on the surface of the NR. Additionally, the biodegraded NR was examined by scanning electron microscopy (SEM), attenuated total reflection–Fourier transform infrared (ATR–FTIR) spectroscopy, and gas chromatography–mass spectrometry (GC–MS). The highest weight loss (69%) of NR was detected (p < 0.05) after 210 d of incubation with the mixed microbial culture (E. coli AY1 + A. oryzae). In the SEM, the surface of the control treatment appeared uniform and normal, whereas the surface of the microbial treatment displayed an irregular shape, with apparent particle deformation and surface erosion. After biodegradation by E. coli AY1 and A. oryzae, the particle size range of the untreated NR dropped from (5.367–9.623 µm) to (2.55–6.549 µm). After treating NR with E. coli AY1 and A. oryzae, new bands appeared in the ATR–FTIR technique; others shifted down in the range of 3910–450 cm−1, suggesting the existence of active groups belonging to alcohol, secondary amine, aromatic amine, conjugated anhydride, aldehyde, alkene, and halo compounds. On the other hand, the GC–MS profile reports a significant decline (p < 0.05) in the amount of hydrocarbons while simultaneously reporting a significant increase (p < 0.05) in the proportion of oxygenated, sulfurous, and nitrogenous compounds. These active groups are attributed to the antioxidant and antibacterial properties of biodegraded NR by a mixture of E. coli AY1 and A. oryzae, which rose 9-fold (p < 0.05) compared to untreated NR. Through the use of this research, we will be able to transform NR waste into a valuable product that possesses both antioxidant and antibacterial properties.

Natural Rubber Powder Production from Latex

Natural rubber-based products are widely used in everyday life. There are three types of upstream processed natural rubber, that are crumb rubber, conventional rubber, and concentrated latex. Latex is easily damaged by clotting and contains 35-40% w/w of water so that the packaging volume is relatively large and inefficient in transportation. Latex also contains ammonia as an anti-clotting agent so the packaging must be special to prevent unpleasant odour. This study aims to create a pilot plant of the spray drying latex from simulation results then test the performance, evaluate the performance test results, as well as making improvements to the production of rubber powder. The steps of this research are data collection for spray dryer design, design verification, construction of spray dryer, spray dryer appliance testing, and characterization of rubber powder produced. The heating system used in the spray dryer is LPG gas-fired furnace. Testing is done by varying the spray dryer drying air temperature of 120°C, 150°C, and 180°C, the water content of the feed latex 70% and 80% w/w, as well as non-stick material such as talc powder and MgO. Rubber powder characterized by water content with digital tools moisture meter and analysed spectra with Fourier Transform Infrared Spectroscopy (FTIR). The results showed the optimum operating conditions for the production of natural rubber powder is drying air temperature of 150°C and the water content of the feed latex 80% w/w. Natural rubber powder produced contains 10 to 13% w/w water but still sticky so that the powder grains stick to each other. The FTIR spectrum analysis of natural rubber powder products show similarity with bonding group of polyisoprene natural rubber compound. Natural rubber powder product can also be used as a substitute for crumb rubber.

Effect of modified rubber powder on the morphology and thermal and mechanical properties of blown poly(lactic acid)–hydroxyl epoxidized natural rubber films for flexible film packaging

ABSTRACTIn this study, we prepared and used modified natural rubber powder to increase the toughness of poly(lactic acid) (PLA) films. We blended PLA and hydroxyl epoxidized natural rubber (HENR) via a melt‐mixing process with twin‐screw extruder and a blowing machine. We investigated the influence of the HENR content in the blend films on the microstructure, thermal, mechanical, and optical properties. The morphology of the blend showed a coarse surface and elongated fibrils of HENR in the PLA matrix. After blowing, the dispersion of small particles of HENR in the substrate was seen. The size of the remaining HENR particles was smaller than that of the starting powder. The compatibility of HENR and the remaining rubber particles may have synergistically contributed to improvements in the elongation at break, impact strength, and ultraviolet–visible transition protection of the PLA films. The elongation at break drastically increased from 3 to 228% after PLA was blended with 20 wt % HENR. On the other hand, all of the blends exhibited lower glass‐transition temperatures and cold crystallization temperatures than the pure PLA films. We concluded that the blend was partially compatible and may have increased the flexibility of the PLA films. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47503.

Properties and recyclability of thermoplastic elastomer prepared from natural rubber powder (NRP) and high density polyethylene (HDPE)

Preparation of thermoplastic natural rubber (TPNR) was carried out by blending high density polyethylene (HDPE) with natural rubber powder (NRP) obtained from spray drying of pre-vulcanized natural rubber latex. The blend ratio of NRP/HDPE was varied and the properties and recyclability of the TPNRs were investigated. The results reveal that, due to flow restriction of the crosslinked NRP, viscosity of the TPNR increases continuously with increasing NRP content. As expected, when NRP content is increased, properties of the TPNR are more rubber-like, as clearly observed from the stress–strain curve characteristics, the reductions in modulus and hardness and, most importantly, the significant improvement of permanent set. Although phase size of the dispersed NRP is relatively large, the tensile strength tends to increase gradually with increasing NRP content. The phenomenon of strain-induced crystallization is proposed to explain the results. It is also found that recycling has a noticeably detrimental influence on most properties of the TPNRs such as tensile strength, tear strength, hardness and tension set. This is thought to be a consequence of thermal degradation of the NRP during the recycling process.

Preparation and mechanical properties of natural rubber powder modified by carbon nanotubes

AbstractA suspension of carbon nanotubes in natural latex was obtained by liquid mixing and then was used to prepare powder natural rubber composites modified with carbon nanotubes by means of spray drying process. The composite powders were round‐like and fine, with an average diameter of less than about 5 μm. The dispersion of carbon nanotubes in the rubber matrix was improved remarkably compared with that obtained by the mechanical mixing method. By means of vulcanization tests, it was found that the addition of vulcanizing agent necessary for the powder rubber containing carbon nanotubes should be evidently greater than that in rubber prepared by mechanical mixing, there evidently existed vulcanization reversions for the natural rubber prepared by mechanical mixing, which disappeared in the powder rubber containing carbon nanotubes prepared by the spray drying process. The mechanical properties of the powder natural rubber containing carbon nanotubes were much improved because of the modification effect of carbon nanotubes in rubber. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4697–4702, 2006

A Novel Approach to Improving the Mechanical Properties in Recycled Vulcanized Natural Rubber and Its Mechanism

Vulcanized rubbers have three-dimensional chemical networks, and as a result they do not melt or dissolve. The presence of these networks creates a tremendous problem at the end of a product's life (i.e., recycling). Recently, R. J. Farris et al. have rediscovered a technique coined “high-pressure high-temperature sintering” (HPHTS) that fuses/sinters 100% vulcanized rubber powder into a solid mass recovering approximately 35−40% of the original mechanical properties. A method of enhancing the mechanical properties of sintered natural rubber powder by incorporating various organic compounds will be discussed in this paper. Additives of different chemical structures such as dienophiles (maleic acid and maleic anhydride), dipolarophiles (phthalimide), and organic acids (benzoic acid, salicyclic acid, and others) are employed. Attenuated total reflection infrared spectroscopy (ATR-IR) and electron ionization mass spectrometry (EIMS) are used to investigate the mechanisms of sintering and the underlying facto...

Natural rubber powder in roads

No disponible