scholarly journals Influence of l-quebrachitol on the properties of centrifuged natural rubber

e-Polymers ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 420-427
Author(s):  
Benxiang Hu ◽  
Yuanbing Zhou ◽  
Ming-Chao Luo ◽  
Yan-Chan Wei ◽  
Gui-Xiang Liu ◽  
...  
Keyword(s):  
Mechanical Property ◽  
Tensile Strength ◽  
Natural Rubber ◽  
Natural Rubber Latex ◽  
Ester Bond ◽  
Rubber Latex ◽  
Strain Induced Crystallization ◽  
Induced Crystallization

Abstract Nonrubber components (NRCs) play an important role in the outstanding mechanical property of natural rubber (NR). The main inositol component of NRCs in natural rubber latex (NRL) is l-quebrachitol. In this study, the influence of l-quebrachitol on the properties of centrifuged natural rubber (CNR) was investigated. The NRL was centrifuged twice to remove most of the NRCs. After that, l-quebrachitol was added in the latex with per hundreds of rubber (phr) vary from 0% to 0.8%, and the vulcanized CNR were prepared. It is shown that the properties of vulcanized CNR were greatly changed, with T 90 reduced from 19 to 15 min, the tensile strength increased from 5 to 9 MPa, T g reduced by about 2°C, and the ability for strain-induced crystallization was enhanced. It was proved by FTIR results that l-quebrachitol was linked to the CNR crosslinking network with ester bond.

scholarly journals Tensile Strength of PHBV/Natural Rubber Latex Mixtures

2015 ◽  
Vol 35 ◽  
pp. 01001
Author(s):  
Sarunya Promkotra ◽  
Tawiwan Kangsadan
Keyword(s):  
Tensile Strength ◽  
Natural Rubber ◽  
Natural Rubber Latex ◽  
Rubber Latex

Preparation and Properties of Acidified Prevulcanized Natural Rubber Latex

2014 ◽  
Vol 997 ◽  
pp. 239-242
Author(s):  
Guang Lu ◽  
He Ping Yu ◽  
Yong Zhou Wang ◽  
Yong Yue Luo ◽  
Zong Qiang Zeng
Keyword(s):  
Tensile Strength ◽  
Acetic Acid ◽  
Natural Rubber ◽  
Acid Content ◽  
Natural Rubber Latex ◽  
Rubber Latex ◽  
Elongation At Break ◽  
Acetic Acid Content ◽  
Hot Air ◽  
Aging Resistance

After a maturation of three days at ambient temperature, the sulfur-prevulcanized natural rubber latex (SNRL) was stabilized by 20wt% Peregal O, and then acidified with the 36wt% acetic acid by a ratio of 5, 15, 25, 35 and 45 g of 36wt% acetic acid to 100g SNRL, to obtain acidified prevulcanized NR latex (ASNRL) with different acidity, respectively. The viscosity of ASNRL increased, while the nitrogen content decreased, with the increment of acetic acid content and the decrease in pH; for unaged samples, the tensile strength, elongation at break, 300% and 500% moduli of the ASNRL films were only slightly lower than those of SNRL film; however the hot-air aging resistance decreased with the increment of acetic acid content.

The Behavior of Carbon Black-Filled Natural Rubber under High Strain Rates3

2006 ◽  
Vol 34 (2) ◽  
pp. 119-134 ◽  
Author(s):  
Syeda A. Hussain ◽  
Michelle S. Hoo Fatt
Keyword(s):  
Tensile Strength ◽  
Carbon Black ◽  
Natural Rubber ◽  
Strain Rate ◽  
Characteristic Relaxation Time ◽  
Dynamic Tensile Strength ◽  
Extension Ratio ◽  
Strain Induced Crystallization ◽  
Quasistatic Loading ◽  
Induced Crystallization

Abstract Tensile tests were conducted to obtain the deformation and failure characteristics of unfilled natural rubber (NR) and natural rubber with 25, 50, and 75 phr of N550 carbon black filler under quasistatic and dynamic loading conditions. The quasistatic tests were performed on an electromechanical INSTRON machine, while the dynamic test data were obtained from tensile impact experiments using a Charpy impact apparatus. In general, the modulus of the stress-extension ratio curves increases with increasing strain rate up to about 407, 367, 346, and 360 s−1 for unfilled, and 25, 50, and 75 phr for filled NR, respectively. Above these strain rates, the unfilled and filled natural rubber stress-extension ratio curves remained unchanged. The modulus increased with increasing strain rate because there was little time for stress relaxation. Above a critical strain rate, no change in modulus was observed because the time of the experiment was short compared to the lowest characteristic relaxation time of the material. Dynamic stress-extension ratio curves did not have the very sharp upturn at break, which is observed from strain-induced crystallization in natural rubber under quasistatic loading. Strain-induced crystallization appeared to be suppressed at high rates of loading. In fact, the highest dynamic tensile strength for the 25- and 50-phr carbon black-filled natural rubbers was smaller than those under quasistatic loading, while the highest dynamic tensile strength of the 75-phr carbon black-filled NR was greater than that in the static test. This indicated that high amounts of carbon black fillers will impede strain-induced crystallization in natural rubber.

Optimisation of Tensile Strength and Weight Loss via Taguchi and Response Surface Method for Natural Rubber Latex Film Consisting Cassava Peel as a Bio-Based Filler

2021 ◽  
Vol 02 (01) ◽  
Author(s):  
Mahiratul Husna Mustaffar ◽  
◽  
Aliff Hisyam A. Razak ◽  
Keyword(s):  
Mechanical Properties ◽  
Weight Loss ◽  
Tensile Strength ◽  
Natural Rubber ◽  
Natural Rubber Latex ◽  
Rubber Latex ◽  
Synthetic Rubber ◽  
Surface Method ◽  
Prepared Composite ◽  
Cassava Peel

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.

Anti-Microbial and Self-Cleaning of Natural Rubber Latex Gloves by Adding Mangosteen Peel Powder

2018 ◽  
Vol 777 ◽  
pp. 3-7 ◽  
Author(s):  
Wasan Moopayuk ◽  
Nuchnapa Tangboriboon
Keyword(s):  
Tensile Strength ◽  
Natural Rubber ◽  
Natural Rubber Latex ◽  
Film Surface ◽  
Latex Film ◽  
Rubber Latex ◽  
Elongation At Break ◽  
Latex Glove ◽  
Latex Gloves ◽  
Mangosteen Peel

Mangosteen peel powder is one of the most important bio-antioxidants. Adding mangosteen peel powder as filler into natural rubber latex compound for latex glove film formation via dipping process can help the green anti-microbial properties. The physical (smoothness and thickness of film) and mechanical properties (tensile strength and elongation at break) of latex film are still good. Therefore, adding mangosteen peel powder into natural rubber latex gloves can reduce the anti-allergic and antimicrobial on the film surface. Mangosteen peel powder ground by rapid mill is fine particle and high surface area 2.4216 m2/g suitable for homogeneous and compatible for adding into natural rubber latex compound. Ceramic hand mold was dipped into the Ca (NO3)2 coagulant only 3 seconds, then dipped into the natural rubber latex compounds added mangosteen peel powder for 15 seconds, withdrawn hand mold slowly, cured in the oven at 120°C for 30 min, then dried at room temperature, and casted it off the hand mold. The obtained natural latex glove films added mangosteen peel powder are smooth, clear, and thin film surface, the highest elongation at break 803.2711 ± 31.6477%, good tensile strength 30.2933 ± 6.0218 MPa, dense film without water leakage, and good contact angle.

Effect of Leaching and Humidity on Prevulcanized NR Latex Films

1997 ◽  
Vol 70 (4) ◽  
pp. 560-571 ◽  
Author(s):  
M. Y. Amir-Hashim ◽  
M. D. Morris ◽  
M. G. O'Brien ◽  
A. S. Farid
Keyword(s):  
Tensile Strength ◽  
Natural Rubber ◽  
Natural Rubber Latex ◽  
High Humidity ◽  
Latex Films ◽  
Rubber Latex ◽  
Softening Effect ◽  
Dry Conditions ◽  
Volume Swelling ◽  
Stiffening Effect

Abstract In an attempt to improve the understanding of the mechanism by which aqueous leaching of prevulcanized natural rubber latex films improves their physical properties, experiments have been carried out on such films after storage under controlled humidity conditions. Under conditions of ambient and high humidity, unleached films were found to absorb much more moisture than their leached counterparts. Results obtained from the equilibrium volume swelling measurements and from the C1 constant of the Mooney-Rivlin plots indicated that crosslink density was not affected by leaching. The effect of leaching on the tensile strength and modulus however was generally significant. Under high humidity conditions an increase in modulus on leaching was observed. These results are explained in terms of the hydrophilic nonrubbers having a stiffening effect under dry conditions and a softening effect when wet. Conditioning humidity also had a direct effect on the tensile strength. As humidity increases, the peak in tensile strength against modulus shifts to lower strength and modulus values. Some of the findings were supported by data from experiments in which a hydrophilic nonrubber component, namely sucrose, was deliberately added to prevulcanized natural rubber latex.

BIO-CACO3 FROM RAW EGGSHELL AS ADDITIVE IN NATURAL RUBBER LATEX GLOVE FILMS

2019 ◽  
Vol 92 (3) ◽  
pp. 558-577
Author(s):  
Nuchnapa Tangboriboon ◽  
Rujika Takkire ◽  
Watchara Sangwan ◽  
Sairung Changkhamchom ◽  
Anuvat Sirivat
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Natural Rubber ◽  
Protein Content ◽  
Natural Rubber Latex ◽  
Film Surface ◽  
Rubber Latex ◽  
Elongation At Break ◽  
Latex Glove ◽  
Low Protein

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.

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
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Carbon Black ◽  
Natural Rubber ◽  
Abrasion Resistance ◽  
Dynamic Properties ◽  
Natural Rubber Latex ◽  
Rubber Latex ◽  
X Ray ◽  
Filler Dispersion

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.

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