HAF/SILICA/NANOCLAY “TERNARY” MASTERBATCH AND HAF/SILICA BINARY MASTERBATCH FROM FRESH NATURAL RUBBER LATEX

2014 ◽  
Vol 87 (2) ◽  
pp. 250-263 ◽  
Author(s):  
Sasidharan Krishnan ◽  
Rosamma Alex ◽  
Thomas Kurian

ABSTRACT A process for production of carbon black/silica/nanoclay ternary filler masterbatch from fresh natural rubber (NR) latex was standardized. The fillers, nanoclay, carbon black, and silica were incorporated in fresh NR latex by a modified coagulation process. The latex, mixed with filler dispersions, coagulated immediately on addition of acids. The coagulum containing fillers was dried at 70 °C in an air oven to get the latex filler masterbatch, which was further processed in the conventional way. The masterbatch compounds containing only silica/carbon black showed a higher level of vulcanization as compared with the corresponding dry mixes. The mechanical properties, such as tensile strength, modulus, tear strength, abrasion resistance, and hardness, increased with the proportion of nanoclay in the mixes up to 5 phr, and with a greater amount, the change was only marginal. Lower tan delta values were observed for all of the masterbatches containing nanoclay in the ranges of 3 to 10 phr compared with the control dry mix containing 25/25 carbon black/silica. The improvement in mechanical properties and dynamic properties shown by the masterbatches over the conventional mill-mixed compounds was attributed to factors related to filler dispersion, as evidenced from the data from dispersion analyzer images, X-ray diffractograms, and a higher level of vulcanization.

Author(s):  
Mahiratul Husna Mustaffar ◽  
◽  
Aliff Hisyam A. Razak ◽  

Disposal latex and synthetic rubber gloves is troublesome such that disposal via incineration and land fill may release poisonous gasses and contaminate soil and water, respectively. As solution to latex and synthetic rubber, biodegradable glove is extensively studied. A bio-based filler is extracted from food waste and blended into natural rubber latex (NRL) as a composite NRL. The effect of biodegradability of composite NRL was studied by varying the loading of bio-based filler in a form of starch dispersion and blended into NRL mixture. Herein some amount of starch can be extracted from cassava peel to be incorporated in NRL for a sustainable and yet biodegradable glove. Previous work on incorporation of cassava-peel filler in NRL has shown a biodegradability without compromising the pristine strength of NRL film at 50% loading starch. In this project, tensile strength and weight loss of prepared composite NRL films were optimised via Taguchi and Response Surface Method (RSM) by means of Design Expert software by varying starch/filler loading, curing temperature and curing drying duration. Due to inadequate data, the optimisation from that previous prepared composite NRL was compared with similar work which utilising NRL and bio-based filler. For Pulungan (2020) study, it can be concluded that the tensile strength of cassava peel starch biodegradable film has the best condition at 50°C to 60°C at approximately 5.5 hours. Elongation optimum conditions shows contrast value of temperature and time. Meanwhile, for Wendy (2020) study, it shows the best percentage loading of cassava-peel starch is at 20% to achieve high stress and strain at break. The optimised mechanical properties via Taguchi and RSM are rather different and hence validation on mechanical properties at above mentioned conditions need to be performed experimentally.


2019 ◽  
Vol 92 (3) ◽  
pp. 558-577
Author(s):  
Nuchnapa Tangboriboon ◽  
Rujika Takkire ◽  
Watchara Sangwan ◽  
Sairung Changkhamchom ◽  
Anuvat Sirivat

ABSTRACT Raw hen eggshell powder, a calcium carbonate source, was used as a biofiller in the natural rubber latex compound and latex glove film formation via dipping process. The powder was anticipated to improve the physical (smoothness and thickness of film) and mechanical properties (tensile strength and elongation at break) of latex film and to reduce the extractable protein content on film surface. Eggshell powder ground by a rapid mill was fine particles of approximately 37.48 μm in diameter, suitable for homogeneous and compatible addition into the natural rubber latex compound. Dipping hand mold into the natural rubber latex compound with 50 wt% eggshell added was the best formula to obtain a smooth, clear, thin film surface, with the tensile strength of 23.24 ± 0.745 MPa and the highest elongation at break of 723.99 ± 14.60%, along with a low protein content, a dense film without water leakage, and with a good contact angle. The natural rubber latex glove film possessed good physical-mechanical properties and a low protein content as the results of the raw eggshell powder added as a biofiller.


1951 ◽  
Vol 24 (3) ◽  
pp. 649-661 ◽  
Author(s):  
Jean Le Bras ◽  
Ivan Piccini

Abstract The direct utilization of latex has up to the present time been limited to a relatively small number of applications because of lack of knowledge of how to communicate to articles sufficient hardness, modulus, resistance to tearing, and resistance to abrasion. It is possible to obtain such properties by combining the molding of latex (thermosensitized by the action of trypsin) with the addition of partially condensed resins. Numerous types of resins can be utilized, but the best results have been obtained by resorcinol-formaldehyde resins. The mechanical properties of vulcanizates thus prepared are extremely high—for example, the tensile strength may reach 7500 pounds per square inch (with an elongation of 700 per cent), and the resistance to tearing 900 pounds per inch. Operating conditions that must be observed for the formation of the resin are described in detail, as well as the influence on the properties of vulcanizates of different factors: length of condensation of the resin, conditions of vulcanization, proportion of catalyst, molecular ratio of constituents, conditions of drying, etc. A new way is opened for obtaining vulcanizates of natural rubber of outstanding mechanical propoerties.


2015 ◽  
Vol 1123 ◽  
pp. 387-390 ◽  
Author(s):  
Hamidah Harahap ◽  
Adrian Hartanto ◽  
Kelvin Hadinatan ◽  
Indra Surya ◽  
Baharin Azahari

The effect of aging on mechanical properties of natural rubber latex (NRL) products filled with alkanolamide-modified cassava peel waste powder (CPWP) was studied. CPWP used as fillers was prepared by milling and sieving it until the size of 100 mesh. The powder then was dispersed in a suspension containing water and alkanolamide in order to modify the prepared powders. The dispersion system of 10 pphr (part per hundred rubber) then was added into NRL matrix followed by pre-vulcanization at 70°C for 10 minutes. The NRL compound then were casted into films by coagulant dipping method then dried at 120°C for 10 minutes. Afterwards, the films were allowed to cool at room temperature for 24 hours before being aged in a circulation of hot air for 24 hours at 70°C. The properties such as tensile strength, tensile modulus, and elongation at break were evaluated between the aged samples and the unaged samples. From this study, it showed that the aged films have increasing value of tensile strength and tensile modulus while the value of elongation at break decreases. These datas are supported by Scanning Electron Microscope (SEM) micrographs which indicate that the change of morphology in NRL films occurs before and after aging.


2021 ◽  
Vol 39 (4) ◽  
pp. 1142-1149
Author(s):  
A.C. Ezika ◽  
V.U. Okpechi

Effects of chemically treated and carbonized spear grass fibre on the curing and mechanical properties of natural rubber vulcanizates were carried out. Natural rubber (NR) was filled with carbonized (at carbonization temperatures of 400°C, 600°C and 800°C  respectively) and chemically treated (treatment with HCl and NaOH of 5% concentration) spear grass fillers respectively, at a filler loading of 30phr. The rubber compounding was carried out in a bambury mixer. The effect of carbonization temperature and chemical treatment of the filler on the mechanical properties (tensile strength, % elongation, hardness strength, abrasion resistance and compression set) and rheological properties (cure time, scorch time, maximum and minimum torque) were carried out on the  samples. The results of the mechanical properties of carbonized spear grass fibre (C-SGF) filled vulcanizates show that the optimum carbonization temperature for an improved tensile strength, % elongation, hardness, abrasion and compression set was obtained at 400°C. NaOH treated fibre filled vulcanizates showed better mechanical properties; with the highest abrasion resistance of 67.65%, while untreated and acidified fibre filled vulcanizates showed poor mechanical properties. Acidified (HCl) uncarbonized spear grass fibre (U-SGF) filled vulcanizate had the highest compression set of 48% against C-SGF filled vulcanzates and carbon black filled  vulcanizate, with carbon black filled vulcanizate having 47% as its compression set value. This reveals that at a carbonization temperature of 400°C, C-SGF appears to be a potential substitute filler for carbon black (CB). Keywords: Spear Grass Fibre, Natural Rubber, Chemical Treatments, Cure Characteristics, Mechanical Properties, Carbonization


2021 ◽  
Vol 19 (3) ◽  
pp. 194-201
Author(s):  
H. Boukfessa ◽  
B. Bezzazi

The present work investigates the effect of the amount of carbon black on curing and mechanical properties such as tensile strength, elongation at break, hardness and abrasion resistance of the natural rubber (NR)/ acrylonitrile-butadiene rubber (NBR) blend. For that purpose, a blend composed of 65% NR and 35% NBR filled with different content of carbon black N330 was used. The curing results indicate that the viscosity and the crosslink density of rubber composites increase and the scorch and curing times decrease with increasing the filler content. Mechanical properties such as tensile modulus and hardness of the CB filled NR/NBR blend were remarkably improved, indicating the inherent reinforcing potential of CB. Regarding tensile strength and abrasion resistance, they increase with the addition of carbon black, up to 50 phr. After that, these properties decrease slightly with filleraddition.


2011 ◽  
Vol 14 (1) ◽  
pp. 30-38
Author(s):  
Hien Quang Pham ◽  
Son Thanh Thanh Do ◽  
Nieu Huu Nguyen

Natural rubber (NR), 30% epoxidized natural rubber (ENR30) and organoclays (Nanomer I28E and I30E) are blended in Brabender. Dispersions of the organoclay in NR are investigated by X – ray diffraction (XRD) and scanning electron microscopy (SEM). The results revealed the increase of dispersion efficiency by the addition of ENR30 as a compatibilizer. The existence of organoclay I28E reduces the vulcanization time, while torque value increases slightly and mechanical properties (abrasion resistance, modulus M100, modulus M300, tensile strength, tear strength) are improved considerably.


2017 ◽  
Vol 5 (4) ◽  
pp. 46-52
Author(s):  
Rismadhani Elita ◽  
Rojiyatul Ikhwani Lubis ◽  
Hamidah Harahap

Leaching process is one of many factors to raise up the mechanical properties of latex products. Studies on the effect of leaching on film natural rubber latex with the filler microcrystalline cellulose from bagasse with alkanolamide using different temperatures and times vulcanization has been done to produce the better mechanical properties such as strenght tensile and elongation at break. Filming of natural rubber latex is done by coagulants dyeing techniques. The study started with the process of pre-vulcanised natural rubber latex at 70 °C with a loading filler by 0 phr, 5 phr, 10 phr and 15 phr and followed by a vulcanization process at a temperature of 100 °C and 150 °C for 10 minutes and 20 minutes. The film result will be have leaching treatment using a solution of water and ammonia 1%. Test results of tensile strength of natural rubber latex film howed that the tensile strength of natural rubber latex film with microcrystalline cellulose as filler and alkanolamides after leaching less than the tensile strength of natural rubber lateks film before leaching


2013 ◽  
Vol 821-822 ◽  
pp. 961-964 ◽  
Author(s):  
Dan Fan ◽  
Xiao Xue Liao ◽  
Shuang Quan Liao ◽  
Yan Fang Zhao ◽  
Jie Sun

Stable aqueous solution of purple carbon black (PCB) was prepared first and then added to prevulcanized natural rubber latex. The effects of the amount of PCB, silane coupling agent and the type of silane coupling agent on the mechanical properties of the vulcanized latex film were researched. The results show that the best mechanical properties were obtained when the vulcanized film was filled with 6 phr PCB modified by KH560. TG shows that thermal stability of the film with PCB modified by KH560 increased. DSC shows that the glass transition temperature of the film increased after adding PCB.


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