Cohesive Strength in Guayule Rubber and Its Improvement through Chemical Promotion

1978 ◽  
Vol 51 (5) ◽  
pp. 863-871 ◽  
Author(s):  
L. F. Ramos de Valle ◽  
M. Montelongo
Keyword(s):  
Tensile Strength ◽  
Energy Consumption ◽  
Natural Rubber ◽  
Tensile Modulus ◽  
Cohesive Strength ◽  
Elongation At Break ◽  
Green Strength ◽  
The Difference

Abstract Green (cohesive) strength of Guayule rubber (GR) was determined and compared to that of natural rubber (NR). In the case of GR gum compounds the green strength was shown to be inferior to that of NR gum compounds; however, in the case of black compounds GR green strength was similar to that of NR. Green strength was very much improved in both rubbers by the addition of MNNA (N-(2-methyl-2-nitropropyl)-4-nitroso aniline) for gum and black compounds. MNNA also acted as an accelerator and thus reduced the difference in vulcanization rate between NR and GR. When using MNNA, a reduction in energy consumption during mastication was also noted. Finally, MNNA notably increased the tensile modulus and decreased the elongation at break for GR vulcanizates, while maintaining an almost constant tensile strength.

Mechanical Properties of Sisal/Coir Hybrid Fibre Reinforced Natural Rubber

2005 ◽  
Vol 21 (3) ◽  
pp. 155-181 ◽  
Author(s):  
A.P. Haseena ◽  
K. Priya Dasan ◽  
G. Unnikrishnan ◽  
Sabu Thomas
Keyword(s):  
Tensile Strength ◽  
Natural Rubber ◽  
Abrasion Resistance ◽  
Tensile Modulus ◽  
Elongation At Break ◽  
Tear Strength ◽  
Green Strength ◽  
Bonding System ◽  
Curing Characteristics ◽  
Hybrid Fibre

Natural rubber was reinforced with various concentrations of sisal and coir fibres. Green strength measurements were carried out to determine the fibre orientation. The rubber–fibre interfacial bond was improved by a resorcinol-hexamethylene tetramine dry bonding system. The composites were vulcanized at 150°C, and the curing characteristics of the hybrid system were studied. The stress- strain behaviour, tensile strength, modulus, elongation at break, tear strength in longitudinal and transverse fibre orientations, Shore-A hardness and abrasion resistance were determined by standard ASTM procedures. The tensile strength, tear strength and tensile modulus increased with the addition of fibres up to 30 phr and then decreased at still higher fibre loadings. The hardness, density and abrasion resistance increased with the addition of fibres whereas the elongation at break decreased. The fracture surfaces of the composites were examined by scanning electron microscopy (SEM). The tensile properties were considered using parallel and Hirsch models.

scholarly journals The effects of alkanolamide addition on cure characteristics, swelling behaviour and tensile properties of silica-filled natural rubber (NR) / chloroprene rubber (CR) blends

2018 ◽  
Vol 34 ◽  
pp. 01030 ◽  
Author(s):  
Indra Surya ◽  
Syahrul Fauzi Siregar ◽  
Hanafi Ismail
Keyword(s):  
Tensile Strength ◽  
Natural Rubber ◽  
Tensile Properties ◽  
Crosslink Density ◽  
Tensile Modulus ◽  
Palm Stearin ◽  
Swelling Behaviour ◽  
Elongation At Break ◽  
Cure Characteristics ◽  
Chloroprene Rubber

Effects of alkanolamide (ALK) addition on cure characteristics, swelling behaviour and tensile properties of silica-filled natural rubber (NR)/chloroprene rubber (CR) blends were investigated. The ALK was synthesized from Refined Bleached Deodorized Palm Stearin (RBDPS) and diethanolamine, and incorporated into the silica-filled NR/CR blends as a non-toxic rubber additive. The ALK loadings were 0.0, 1.0, 3.0, 5.0 and 7.0 phr. It was found that the ALK exhibited shorter scorch and cure times and higher elongation at break of the silica-filled NR/CR blends. The ALK also exhibited higher torque differences, tensile modulus and tensile strength at a 1.0 phr of ALK loading and then decreased with further increases in the ALK loading. The swelling measurement proved that the 1.0 phr loading of ALK caused the highest degree in crosslink density of the silica-filled NR/CR blends.

Effect of Gamma Radiation on Properties of Cellulose Nanocrystal/Natural Rubber Nanocomposites

2018 ◽  
Vol 772 ◽  
pp. 13-17 ◽  
Author(s):  
Wapoon Tappanawatch ◽  
Paweena Prapainainar ◽  
Pongdhorn Sae-Oui ◽  
Surapich Loykulnant ◽  
Peerapan Dittanet
Keyword(s):  
Tensile Strength ◽  
Natural Rubber ◽  
Gamma Ray ◽  
Mechanical Performance ◽  
Reaction Times ◽  
Tensile Modulus ◽  
Alkaline Treatment ◽  
Corn Cob ◽  
Elongation At Break ◽  
Reinforcing Agent

Cellulose nanocrystals (CNC) were extracted from corn cob and synthesized by alkaline treatment using 3 wt% sodium hydroxide (NaOH). Acid hydrolysis with 64 wt% sulfuric acid (H2SO4) at different reaction times (30, 45, 60 min) was performed to obtain CNC solutions. CNC was evaluated as a reinforcing agent in natural rubber (NR) at CNC loadings from 1-5 wt%. Gamma-ray radiation was used as vulcanization method and varied at 10 and 20 kGy. The tensile modulus and tensile strength of NR vulcanizates increased with addition of CNC and contents. In addition, radiation by gamma ray impacts the mechanical performance, where CNC/NR composites vulcanized with higher dose of radiation of 20 KGy were found to have the higher values in tensile strength, elongation at break, and modulus than with 10 KGy. Moreover, the tensile strength and elongation at break of the composites after aging were found to slightly increase due to post-curing during the aging process.

Preparation and Properties of Sponge Rubber Based on Natural Rubber and Cassava Starch

2014 ◽  
Vol 931-932 ◽  
pp. 68-72
Author(s):  
Komsun Temna ◽  
Nitinart Saetung ◽  
Anuwat Saetung
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Natural Rubber ◽  
Cassava Starch ◽  
Interfacial Interaction ◽  
Morphological Properties ◽  
Elongation At Break ◽  
Cure Time ◽  
The Difference ◽  
Cure Characteristic

In this work, the sponge rubbers based on cassava starch masterbatch in latex phase with the difference technique (non-gelatinized and gelatinized cassava starch) were preformed. The cassava starch contents from 0 to 70 phr were also studied. The cure characteristic, mechanical and morphological properties were investigated. It was found that the scorch time and cure time were increased with an increasing of cassava starch contents in both techniques. The mechanical properties i.e., tensile strength, elongation at break and tear strength were decreased with an increasing of cassava starch contents, except 500% modulus. However, the sponge based on gelatinized technique gave the better mechanical properties than that of non-gelatinized cassava starch. The SEM micrographs of sponge NR from gelatinized technique were also able to confirm a good interfacial interaction between hydrophilic cassava starch and hydrophobic NR.

Waste Silicon Carbide as Filler for Natural Rubber Compounds

2014 ◽  
Vol 979 ◽  
pp. 155-158 ◽  
Author(s):  
Apaipan Rattanapan ◽  
Jitrakha Paksamut ◽  
Pornsri Pakeyangkoon ◽  
Surakit Tuampoemsab
Keyword(s):  
Silicon Carbide ◽  
Tensile Strength ◽  
Natural Rubber ◽  
Shear Viscosity ◽  
Tensile Modulus ◽  
Filler Loading ◽  
Extrudate Swell ◽  
Elongation At Break ◽  
Roll Mill ◽  
Cure Time

This work studied possibilities of using waste silicon carbide (SiC) particles from abrasive industry as alternative filler in natural rubber (NR) compounds. The rubber was prepared by using natural rubber grade STR 5L and waste silicon carbide loading of 0, 10, 20, 30 and 40 phr. Firstly, the rubber were compounded by using two roll mill and then using Oscillating Disc Rheometer for studying cure time at one hundred and fifty degree Celsius. Then, shear viscosity and extrudate swell of the compounded natural rubber were characterized by using capillary rheometer at 100°C. The result showed that the apparent shear viscosity increased slightly with increasing waste silicon carbide loading and the percentage of extrudate swell was found to be a decreasing function of the filler loading. Then, test tensile by using the prepared samples for studying tensile modulus, tensile strength and elongation at break. The result showed that tensile modulus and tensile strength increased with increasing waste silicon carbide. On the other hand, the elongation at break of the filled natural rubber decreased with increasing waste silicon carbide. Finally, bring the sample to test hardness by using shore A. Results indicated that waste silicon carbide direct variation with the indicator of hardness.

Effect of Aging on Mechanical Properties of Natural Rubber Latex Products Filled with Alkanolamide-Modified Cassava Peel Waste Powder (CPWP)

2015 ◽  
Vol 1123 ◽  
pp. 387-390 ◽  
Author(s):  
Hamidah Harahap ◽  
Adrian Hartanto ◽  
Kelvin Hadinatan ◽  
Indra Surya ◽  
Baharin Azahari
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Natural Rubber ◽  
Natural Rubber Latex ◽  
Tensile Modulus ◽  
Rubber Latex ◽  
Elongation At Break ◽  
Hot Air ◽  
Before And After ◽  
Cassava Peel

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.

Cellular Bi2O3/natural rubber composites for light-weight and lead-free gamma-shielding materials and their properties under gamma irradiation

2021 ◽  
pp. 0021955X2199735
Author(s):  
Phakamat Limarun ◽  
Teerasak Markpin ◽  
Narongrit Sombatsompop ◽  
Ekachai Wimolmala ◽  
Kiadtisak Saenboonruang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Natural Rubber ◽  
Gamma Irradiation ◽  
Attenuation Coefficient ◽  
Tensile Modulus ◽  
Lead Free ◽  
Morphological Properties ◽  
Light Weight ◽  
Elongation At Break

This work investigated the effects of a radiation-protective filler, namely bismuth oxide (Bi2O3), and blowing agents, namely azodicarbonamide (ADC) and oxy-bis (benzene sulfonyl) hydrazide (OBSH), on gamma attenuation and the mechanical, physical, and morphological properties of cellular natural rubber (NR) composites for potential use as light-weight and lead-free gamma-shielding materials. The contents of Bi2O3 were varied from 100 to 300 and 500 parts per hundred of rubber by weight (phr) and the contents of ADC or OBSH were varied from 0 to 8 and 16 phr. The results indicated that the addition of Bi2O3 enhanced the overall gamma-shielding ability, density, tensile modulus, and hardness (Shore OO), but lowered the tensile strength and elongation at break. On the other hand, the addition of ADC or OBSH resulted in decreases in the density, linear attenuation coefficient ( μ), and overall tensile properties but an increase in the mass attenuation coefficient ( μm), with ADC producing better mechanical properties than samples with OBSH. In addition, investigations on the properties of the cellular Bi2O3/NR composites under additional 35 kGy and 70 kGy gamma irradiation revealed that the irradiated samples had increased density, tensile modulus, and hardness (Shore OO), but decreased tensile strength, elongation at break, and μm after such ageing. In conclusion, the overall results suggested that the developed cellular Bi2O3/NR composites not only had efficient and promising gamma-shielding and mechanical properties but also offered comfort and light-weight to users, which could potentially reduce discomforts caused by wearing heavier conventional radiation-protective equipment.

Influence of Modified Cassava Peel Waste (CPW) Loading on Tensile Properties of Natural Rubber Latex (NRL) Products

2015 ◽  
Vol 1119 ◽  
pp. 342-346
Author(s):  
Hamidah Harahap ◽  
Kelvin Hadinatan ◽  
Adrian Hartanto ◽  
Elmer Surya ◽  
Indra Surya ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Natural Rubber ◽  
Crosslink Density ◽  
Natural Rubber Latex ◽  
Tensile Modulus ◽  
Rubber Matrix ◽  
Tensile Fracture ◽  
Rubber Latex ◽  
Elongation At Break ◽  
Cassava Peel

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.

Extended Poly(Phenylquinoxalines) Containing Earbonyl and Sulfide Connecting Groups

1993 ◽  
Vol 5 (4) ◽  
pp. 285-295 ◽  
Author(s):  
Rooma Mago Mehta ◽  
R G Basst ◽  
Rajendra K Singh
Keyword(s):  
Tensile Strength ◽  
Chloroform Solution ◽  
Tensile Modulus ◽  
Aromatic Rings ◽  
Elongation At Break ◽  
Glass Transition Temperatures ◽  
Hydrocarbon Solvents ◽  
Polymer Decomposition ◽  
The Difference ◽  
Bonding Characteristics

Novel poly(phenylquinoxalines) (PPQs) containing carbonyl and sulfide connecting groups between the aromatic rings were prepared by condensation of various aromatic bis(o-diamines) with novel extended bis(phenyl-1.2-diketones) in m-cresol. An objective of the work was to determine the effect of replacing oxygen by sulfur in extended PPQs. The polymers prepared were soluble in m-cresol, dimethylsulfoxide, N,Ndimethylacetamide, 1-methyl-2-pyrrolidinone and chlorinated hydrocarbon solvents, and had inherent viscosities as high as 1.23 dl g-1. The PPQs exhibited glass transition temperatures ranging from 217 to 245 C and polymer decomposition temperatures (10% weight loss) as measured by thermogravimetric analysis of 526-568 in air and 510-549 CC in helium. A tough transparent yellow fingernail creasable film with a tensile strength of 94.7 MPa, a tensile modulus of 2562 MPa and elongation at break of 6.4% at 25 "C was cast from a chloroform solution of the polymer prepared from 1,3-bis(phenylglyoxalyl-4phenylthio-4'-benzoyl)benzene and 3,3'-diaminobenzidine. Little difference in properties was observed in the PPQs prepared as compared to the PPQs containing carbonyl and ether connecting groups between the aromatic rings, in spite of the difference in the bonding characteristics of carbon to sulfur and to oxygen.

scholarly journals PENGARUH PENAMBAHAN ALKANOLAMIDA TERHADAP SIFAT-SIFAT UJI TARIK VULKANISAT KARET ALAM BERPENGISI KAOLIN

2013 ◽  
Vol 2 (4) ◽  
pp. 1-5
Author(s):  
Yudha Widyanata ◽  
Indah M.S. Sitorus ◽  
Indra Surya
Keyword(s):  
Tensile Strength ◽  
Natural Rubber ◽  
Tensile Properties ◽  
Crosslink Density ◽  
Density Measurement ◽  
Tensile Modulus ◽  
Rubber Compound ◽  
Elongation At Break ◽  
Break Up

By using a semi-efficient vulcanization system, Alkanolamide (ALK) was incorporated into kaolin-filled natural rubber compound at 1.0; 3.0; 5.0 and 7.0 parts per hundred rubber (phr). An investigation was carried out to examine the effect of ALK on tensile properties of the kaolin filled-natural rubber compound. It was found that ALK exhibited higher tensile modulus, tensile strength, and elongation at break up to 5.0 phr of ALK loading and then decreased with further increasing of ALK loading. Crosslink density measurement proved that 5.0 phr loading of ALK in the kaolin-filled natural rubber system exhibited greatest tensile properties due to its highest crosslink density formation.

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