Characterizing Mechanical Properties of Peroxide-Vulcanized Natural Rubber Latex Films

2015 ◽  
Vol 1134 ◽  
pp. 236-242 ◽  
Author(s):  
Roslim Ramli ◽  
Jefri Jaapar ◽  
Manroshan Singh Jaswan Singh ◽  
Siti Noor Suzila Maqsood Ul Haque ◽  
Amir Hashim Md Yatim

Natural rubber latex is the material of choice for the fabrication of thin elastic films in many products such as gloves and condoms owing to its high strength, elasticity, comfort in use, good barrier properties and ‘green image’ [1, 2]. This unique combination of characteristics has its origins in the intrinsic properties of the crosslinked polymer network within the rubber matrix. The crosslinking of rubber hydrocarbon chains by free radicals generated from peroxide has been discovered for many years [3]. In peroxide crosslinking reactions, organic peroxide decomposes to produce reactive free radicals that will react to release hydrogen ions from the carbon hydrogen in the polymer chain, encouraging formation of free radicals on the rubber molecular chains. As the free radicals react with the polymer chains, the carbon hydrogen in the chains act as reactive centre that combines with centres of other rubber chains to form a network of carbon to carbon bonds which serve as crosslinks [3, 4].

e-Polymers ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 179-185
Author(s):  
Ya-Dong Yang ◽  
Gui-Xiang Liu ◽  
Yan-Chan Wei ◽  
Shuangquan Liao ◽  
Ming-Chao Luo

Abstract Low strength has always been one of the main factors limiting the application of foams. We acquire a natural rubber latex/MXene foam composite with high strength and versatility by adding MXene to the natural rubber latex. It is shown that natural rubber latex foam (NRF) with 2 and 3 phr of MXene shows obviously enhanced tensile strength by 171% and 157% separately as compared to that of neat NRF. Furthermore, the composite also has better electrical conductivity and electromagnetic shielding than NRF, which can be used in the automotive industry, aviation industry, and many other aspects.


2015 ◽  
Vol 1119 ◽  
pp. 342-346
Author(s):  
Hamidah Harahap ◽  
Kelvin Hadinatan ◽  
Adrian Hartanto ◽  
Elmer Surya ◽  
Indra Surya ◽  
...  

Cassava peel is one of agricultural waste that abundantly found in environment. One approach to manage this waste is to apply it as filler in natural rubber latex. In this work, the cassava peel waste (CPW) was powdered and dispersed in alkanolamide-water dispersion system to modify its surface. The amount of fillers used was 0, 5, 10, 15, 20 and 25 phr (part per hundred rubber) and loaded in natural rubber latex (NRL) formulation system. The products then were formed by dipping method after the NRL formulation was pre-vulcanized at 70°C. The observed parameter includes crosslink density, tensile strength, tensile modulus and elongation at break. Scanning Electron Microscope (SEM) was used to study the morphology of tensile fracture in NRL film. The results show that 10 phr loading of modified fillers increases the crosslink density, tensile strength, and tensile modulus but decreases the elongation at break. SEM study also reveals that higher filler loading above 10 phr will create the agglomeration in rubber matrix.


2018 ◽  
Vol 34 (2) ◽  
pp. 75-87 ◽  
Author(s):  
K Anand ◽  
Siby Varghese ◽  
Thomas Kurian ◽  
Suryasarathi Bose

The incorporation of bio-nanofillers such as starch nanocrystals (SNC) in polymer matrices received much attention owing to their biodegradable nature. In this work, starch nanocrystals have been isolated from modified corn starch by acid hydrolysis and their efficacy as a potential bio-filler for natural rubber latex (NR) has been explored. The quality of the SNC suspension was confirmed from dynamic light scattering (DLS) studies and X-ray diffraction (XRD) measurements. For the fabrication of nanocomposites of NR with corn starch crystals, a simple latex stage mixing procedure was employed. The platelet-like morphology of corn starch nanocrystals improved the barrier properties of NR based vulcanizates with the addition of the SNC suspension.


BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 9507-9522
Author(s):  
Nurul Jannah Sallehuddin ◽  
Hanafi Ismail

Non-treated and silane-treated kenaf bast/natural rubber latex foam (NRLF) were prepared using the Dunlop method at different filler loading (0, 3, 5, and 7 pphr). The properties were investigated in terms of mechanical properties, tensile, compression, hardness, and swelling behavior. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were used to characterize kenaf bast/NRLF. With the modulus at 100% elongation (M100), the compression strength and hardness showed increments in value with increments of kenaf loading. However, different results showed in tensile strength, elongation at break, swelling percentage, and recovery percentage, which decreased at higher filler loading. Silane-treated kenaf bast/NRLF showed higher value in all properties except for elongation at break, swelling, and recovery percentage. The improvement of properties was supported by SEM surface morphological studies that showed better adhesion between the rubber matrix and kenaf filler.


2013 ◽  
Vol 747 ◽  
pp. 721-724 ◽  
Author(s):  
S. Utara ◽  
U. Moonart

Ultrasonic degradation of fresh latex was investigated at frequencies of 20 and 25 kHz, at a constant temperature of 25o C (±1o C) to avoid temperature-related effects. The time-dependent evolution of the molecular weight of the natural rubber latex was determined using gel permeation chromatography, and its structure by means of the fourier transform infrared (FTIR) technique. A 10 minute period of sonication resulted in reduction in the molecular weight of both the 20 and 25 kHz treated samples, the lowest average molecular weight () being obtained in the case of the 25 kHz sample. The of the 25 kHz sample also decreased with increasing latex concentration. However, after 30 minutes, fluctuations had occurred in both samples with respect to the and and also the molecular weight distributions, an effect possibly explained by the competing processes of chain scission and radically-induced cross-linking of the polymer chains. The FTIR results also suggest that the structure of polyisoprene is unaltered by ultrasonic wave treatment at these frequencies.


2011 ◽  
Vol 396-398 ◽  
pp. 400-406 ◽  
Author(s):  
Guang Lu ◽  
He Ping Yu ◽  
Zong Qiang Zeng ◽  
Yong Yue Luo

The acidfied sulfur-prevulcanized natural rubber (NR) latex was mixed with 1~20 parts per hundred rubber (phr) of a 2wt% solution of chitosan (CS) in 1wt% acetic acid, then cast to preapare a series of NR/CS semi-interpenetrating polymer network (semi-IPN) films; the NR/CS semi-IPN films were further treated with 0.5wt% glutaraldehyde(GA)solution for respectively 1, 3 and 6h to obtain NR/CS IPN films. The mechanical properties and swelling behavours in various media of water, toluene and reference olis of IRM901 and IRM 903 of these films were studied and compared with those pure sulfur-prevulcanized natural rubber latex (SNRL) film. Results showed that, NR/CS IPN films with better mechanical properties could be obained by treating the 24h-leached NR/CS semi-IPN films than by treating directly the unleached ones with 0.5wt% GA solution; the tear strength, 300% modulus, Shore A hardness, hydrophilicity and resistance to non-polar solvents and oil of the SNRL films increased with the incorporation of CS, while the NR/CS IPN films exhibited better than the NR/CS semi-IPN films, especially in tear strength enhancement; the tensile strength and elongation at break of NR/CS semi-IPN and IPN films gradually decreased with the increase in CS content. However, most of the elasticity of pure NR vulcanizate could be reserved, when the CS content was not greater than 15 phr.


2015 ◽  
Vol 754-755 ◽  
pp. 261-265
Author(s):  
M.M. Afiq ◽  
N.T. Sean ◽  
A. Rashid Azura

Sago starch is modified with 1 wt % Poly butyl acrylate (PBA) and Poly ethylene oxide (PEO) monomer and 1 wt% of initiator, potassium persulfate (PPS) at temperature 80°C for 2 hours. Modified sago starch is cooled under room temperature for 24 hours prior to Natural Rubber Latex (NRL) compounding process. Results indicates that NRL films with PBA modified sago starch have higher mechanical properties compared to PEO modified sago starch and unmodified sago starch. Swelling test indicates that PEO gives lowest percentage of swelling and crosslink density. This is due to higher reaction probability that produce more closely packed structure with NRL matrix compared to PBA which only improved the compatibility of sago starch particle with rubber matrix. Thus, chemically modified sago starches are preferable to be used as fillers to produce better interaction between fillers and rubber matrix.


2019 ◽  
Vol 821 ◽  
pp. 74-80
Author(s):  
Wichudaporn Seangyen ◽  
Paweena Prapainainar ◽  
Pongdhorn Sae-Oui ◽  
Surapich Loykulnant ◽  
Peerapan Dittanet

In-situ silica nanoparticles with ammonium laurate surfactant in natural rubber latex composites were characterized to describe the reinforcement mechanism in enhanced mechanical properties. In-situ sol-gel method was introduced to generate silica nanoparticles in natural rubber latex using a mole ratio of water-to-TEOS of 28.9 stirring at room temperature for 24 hours. The addition and effect of adding ammonium laurate surfactant for enhancing dispersion and compatibility between silica nanoparticles and rubber matrix was also studied. The natural rubber latex was then vulcanized by electron beam radiation at 200 kGy. The silica content in rubber composites made in-situ, was analyzed by TGA, showed an increase from 3.08 phr to 8.92 phr, corresponding to addition of TEOS amounts of 10 phr to 30 phr, respectively. The dispersion of silica nanoparticles in rubber matrix with ammonium laurate surfactant was improved and exhibited less aggregation than rubber composites absent of ammonium laurate surfactant as evidenced by SEM-EDX. The increase of silica content in rubber composites exhibited lower swelling ratio and higher crosslink density when compared with neat natural rubber. Also, the modulus at 100% and 300% strain also increased with increasing silica nanoparticles incorporation in contrast to tensile strength.


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