Enhancing Dispersion of Silica Nanoparticles with Ammonium Laurate Surfactant for Natural Rubber Latex Composites

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.

2018 ◽  
Vol 936 ◽  
pp. 31-36 ◽  
Author(s):  
Wichudaporn Seangyen ◽  
Paweena Prapainainar ◽  
Pongdhorn Sae-Oui ◽  
Surapich Loykulnant ◽  
Peerapan Dittanet

Silica nanoparticles were synthesized by rice husk ash (RHA) produced from jasmine rice husk and riceberry rice husk via sol-gel method for the use as reinforcing fillers in natural rubber (NR). The obtained silica nanoparticles are spherical in shape and the particle sizes were observed to be in the 10-20 nm range with uniformly size distribution. The surface of silica nanoparticles was treated with a silane coupling agent confirmed by FTIR. The treated silica nanoparticles were then incorporated into NR and vulcanized with electron beam irradiation. The rubber nanocomposites with silica nanoparticles, produced from jasmine rice husk and riceberry rice husk, resulted in higher mechanical properties (tensile strength and modulus) than neat rubber vulcanizate. The modified rubber vulcanizates revealed rougher surface with tear lines as compared to the neat rubber vulcanizates, indicating the improved strength. Interestingly, the rubber nanocomposites with silica nanoparticles from jasmine rice husk showed higher tensile strength and modulus than silica nanoparticles produced from riceberry rice husk. The micrographs indicated better dispersion of NR composites with jasmine rice husk which leads to a strong interaction between silica nanoparticles and rubber matrix, thereby improving the strength.


2018 ◽  
Vol 92 (2) ◽  
pp. 219-236 ◽  
Author(s):  
Naresh D. Bansod ◽  
Bharat P. Kapgate ◽  
Pradip K. Maji ◽  
Anasuya Bandyopadhyay ◽  
Chayan Das

ABSTRACT Functionalization of non-polar ethylene propylene diene monomer (EPDM) rubber by melt grafting of maleic anhydride (MA) and in situ incorporation of sol–gel derived silica in the MA grafted EPDM has been done to prepare EPDM/silica composites to use dual benefits of both the approaches, which results in adequate rubber–filler compatibility, good filler dispersion, and enhanced composite properties. Controlled growth of silica up to 25 parts per hundred rubber (phr) is carried out with the solution sol–gel process using tetraethoxysilane (TEOS) as a silica precursor. Mechanical and dynamical properties of the composites are found to improve consistently as silica content increases. Furthermore, treatment of maleic anhydride grafted EPDM by γ-aminopropyltrimethoxysilane (γ-APS) results in remarkable improvement in composite properties even at the same silica content. This is attributed to the generation of uniformly dispersed spherically shaped nanosilica throughout the rubber matrix as observed in a transmission electron microscopic (TEM) study. This contributes to enhanced crosslinking density and improved rubber–filler interaction. In fact, the reinforcement effect brought by in situ silica relative to unmodified in situ silica/EPDM composites is found to be much higher than that reported in recent work on EPDM/in situ silica composites even with higher silica loading. The mechanical, rheological, and dynamic mechanical behaviors of all the composites are evaluated and compared in detail.


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].


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.


Polymers ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1216 ◽  
Author(s):  
Suhawati Ibrahim ◽  
Nadras Othman ◽  
Srimala Sreekantan ◽  
Kim Tan ◽  
Zairossani Mohd Nor ◽  
...  

Natural rubber is one of the most important renewable biopolymers used in many applications due to its special properties that cannot be easily mimicked by synthetic polymers. To sustain the existence of natural rubber in industries, modifications have been made to its chemical structure from time to time in order to obtain new properties and to enable it to be employed in new applications. The chemical structure of natural rubber can be modified by exposure to ultraviolet light to reduce its molecular weight. Under controlled conditions, the natural rubber chains will be broken by photodegradation to yield low-molecular-weight natural rubber. The aim of this work was to obtain what is known as liquid natural rubber via photodegradation, with titanium dioxide nanocrystals as the catalyst. Titanium dioxide, which was firstly synthesized using the sol–gel method, was confirmed to be in the form of an anatase, with a size of about 10 nm. In this work, the photodegradation was carried out in latex state and yielded low-molecular-weight natural rubber latex of less than 10,000 g/mol. The presence of hydroxyl and carbonyl groups on the liquid natural rubber (LNR) chains was observed, resulting from the breaking of the chains. Scanning electron microscopy of the NR latex particles showed that titanium dioxide nanocrystals were embedded on the latex surface, but then detached during the degradation reaction.


2012 ◽  
Vol 626 ◽  
pp. 530-536 ◽  
Author(s):  
Shamala Ramasamy ◽  
Hanafi Ismail ◽  
Yamuna Munusamy

Rice husk powder (RHP) which is a fibrous agricultural waste is widely used as potential filler, novel adsorbent or coating for dry polymers. However, the compatibility of RHP with natural rubber latex (NRL) is yet to be studied. The main goal of this reported work was to create a method to incorporate RHP with NRL and achieve a compatible dispersion. However the amorphous silica content (acidic nature) in RHP makes it difficult to directly incorporate RHP to NRL compound. In this research, RHP was modified by adding ammonia, distilled water and dispersing agents to make an aqueous compatible alkaline dispersion for NRL. Also the particle size of RHP is reduced up to - 300micron to make it more compatible with the NRL. The compatibility of modified RHP is analyzed by sedimentation with time, particle size analyzer, pH and morphology study. The test results supports that modified RHP is more compatible with the NRL compound to obtain a stable foam in NRLF preparation.


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.


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