scholarly journals Degradation of non-vulcanized natural rubber renewable resource for fine chemicals used in polymer synthesis

Polímeros ◽  
2013 ◽  
Vol 23 (4) ◽  
pp. 441-450 ◽  
Author(s):  
Alexander FAINLEIB ◽  
Renata V. PIRES ◽  
Elizabete F. LUCAS ◽  
Bluma G. SOARES
Keyword(s):  
Natural Rubber ◽  
Renewable Resource ◽  
Polymer Synthesis ◽  
Fine Chemicals

New Ionic Polymer: Synthesis and Properties of “Zinc Sulfonated Natural Rubber”

2002 ◽  
Vol 34 (1) ◽  
pp. 91-101 ◽  
Author(s):  
Thommachan Xavier ◽  
Jacob Samuel ◽  
K. B. Manjooran ◽  
T. Kurian
Keyword(s):  
Natural Rubber ◽  
Polymer Synthesis ◽  
Ionic Polymer

scholarly journals Influence of Filler from a Renewable Resource and Silane Coupling Agent on the Properties of Epoxidized Natural Rubber Vulcanizates

2015 ◽  
Vol 2015 ◽  
pp. 1-15 ◽  
Author(s):  
Wiphawadee Pongdong ◽  
Charoen Nakason ◽  
Claudia Kummerlöwe ◽  
Norbert Vennemann
Keyword(s):  
Mechanical Properties ◽  
Metal Oxide ◽  
Natural Rubber ◽  
Elevated Temperatures ◽  
Polymer Network ◽  
Renewable Resource ◽  
Dynamic Mechanical Properties ◽  
Epoxidized Natural Rubber ◽  
Cure Characteristics ◽  
Temperature Scanning

Rice husk ash (RHA) was used as a reinforcing filler in epoxidized natural rubber (ENR) with various loading levels (0, 10, 20, and 30 phr), and silica filled ENR was also studied for comparison. The effects of RHA content on cure characteristics, mechanical properties, dynamic mechanical properties, and thermoelastic behavior of the filled ENR composites were investigated. It was found that the incorporation of RHA significantly affected the cure characteristics and mechanical properties. That is, the incorporation of RHA caused faster curing reactions and increased Young’s modulus and tensile strength relative to the unfilled compound. This might be attributed to the metal oxide impurities in RHA that enhance the crosslinking reactions, thus increasing the crosslink density. Further improvements in the curing behavior and the mechanical properties of the filled composites were achieved byin situsilanization with bis(triethoxysilylpropyl) tetrasulfide (Si69). It was found that the rubber-filler interactions reinforced the composites. This was indicated by the decreased damping characteristic(tan ⁡δ)and the other changes in the mechanical properties. Furthermore, the ENR composites with Si69 had improved filler dispersion. Temperature scanning stress relaxation (TSSR) results suggest that the metal oxide impurities in RHA promote degradation of the polymer network at elevated temperatures.

scholarly journals Guayule (Parthenium argentatum A. Gray), a Renewable Resource for Natural Polyisoprene and Resin: Composition, Processes and Applications

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 664
Author(s):  
Amandine Rousset ◽  
Ali Amor ◽  
Teerasak Punvichai ◽  
Sandrine Perino ◽  
Serge Palu ◽  
...  
Keyword(s):  
Natural Rubber ◽  
Current Knowledge ◽  
Renewable Resource ◽  
Sole Source ◽  
Southern United States ◽  
Parthenium Argentatum ◽  
Northern Mexico ◽  
Botanical Description ◽  
Multiple Product ◽  
Economic Considerations

Natural rubber is an essential material, especially for plane and truck tyres but also for medical gloves. Asia ranks first in the production of natural rubber, of which the Hevea tree is currently the sole source. However, it is anticipated that this source alone will not be able to fulfill the growing demand. Guayule, a shrub native to northern Mexico and southern United States, may also contribute. This plant not only contains polyisoprene, but also resin, a mixture of lipids and terpenoids. This review summarizes various aspects of this plant, from the usage history, botanical description, geographical distribution and cultivation practices, down to polyisoprene and resin biosynthesis including their distribution within the plant and molecular composition. Finally, the main processes yielding dry rubber or latex are depicted, as well as the properties of the various extracts along with economic considerations. The aim is to provide a wide picture of current knowledge available about this promising crop, a good feedstock candidate for a multiple-product biorefinery.

In Situ Filling of Silica onto “Green” Natural Rubber by the Sol—Gel Process

2001 ◽  
Vol 74 (1) ◽  
pp. 16-27 ◽  
Author(s):  
S. Kohjiya ◽  
K. Murakami ◽  
S. Iio ◽  
T. Tanahashi ◽  
Y. Ikeda
Keyword(s):  
Natural Rubber ◽  
Silica Surface ◽  
Sol Gel ◽  
Renewable Resource ◽  
Crosslinking Density ◽  
Silica Particles ◽  
Rubber Matrix ◽  
In Situ Silica ◽  
Silica Composite

Abstract The sol—gel reaction of tetraethoxysilane produced the fine and well-dispersed in situ silica particles in the “green” natural rubber (NR) matrix before curing. This new method was developed for a NR/silica composite material, and a good reinforcement effect of in situ silica was observed on the NR vulcanizate. The method is expected to be an industrially practical technique. The in situ silica did not much inhibit the accelerated sulfur curing. Thus, it is estimated that the concentration of silanol groups on the in situ silica surface was smaller than those on the conventional silica surface. The silica—silica interaction of in situ silica seems to be weaker to result in better dispersion in the rubber matrix compared with the conventional silica. Atomic force microscopy suggested that the wettability of NR onto in situ silica was higher than that onto conventional silica. The hardness, modulus at 50% elongation and the storage modulus at room temperature of in situ silica-filled NR vulcanizate were smaller than those of conventional silica-filled NR vulcanizate, although the crosslinking density of the former was larger than that of the latter and their silica contents were comparable. These unique characteristics of in situ silica-filled vulcanizate seem to be ascribed to the fine and well-dispersed in situ silica particles in the NR matrix. These observations suggest that NR (a renewable resource)/in situ silica composite has much potential as an ecologically “green” material in the rubber industry.

Effects of Type and Concentration of Initiator on Grafting of Acrylic Monomer onto Depolymerized Natural Rubber

2011 ◽  
Vol 264-265 ◽  
pp. 565-570 ◽  
Author(s):  
N. Prasoetsopha ◽  
Pranee Chumsamrong ◽  
Nitinat Suppakarn
Keyword(s):  
Natural Rubber ◽  
Epoxy Resin ◽  
Natural Rubber Latex ◽  
Reaction Times ◽  
Gel Permeation Chromatography ◽  
Renewable Resource ◽  
Good Evidence ◽  
Proton Nuclear Magnetic Resonance ◽  
Monomer Mixture ◽  
Air Oxidation

Highly crosslinked epoxy resin for engineering applications is normally stiff but brittle. Therefore, many attempts have been made to improve its toughness. Nowadays, several studies have been done on toughening epoxy resin using natural rubber (NR) because it is abundant and comes from renewable resource. In the present work, NR was subjected to depolymerize in order to achieve molecular dispersion of NR in epoxy matrix. Depolymerized natural rubber (DNR) was prepared by adding a carbonyl compound to natural rubber latex solution and subjecting the mixture to air oxidation in the presence of a radical forming agent at 70°C. In addition, the interfacial adhesion between rubber and matrix must be present to achieve a significant increase in toughness. Hence, DNR was further functionalized by grafting with monomer mixture of methyl methacrylate (MMA)/glycidyl methacrylate (GMA) (90/10 wt/wt%) in an amount of 50% based on rubber content. Solution polymerization was used to graft such monomers using 2 hours reaction times at a reaction temperature of 80oC. Two types of initiator used were benzoyl peroxide (BPO) and azo-bisisobutyronitrile (AIBN). The amounts of initiator in the grafting process were 1, 2, and 3 parts per hundred of DNR. Effects of type and concentration of initiator on grafting efficiency of MMA/GMA monomer mixture onto depolymerized natural rubber were studied by proton nuclear magnetic resonance (1H-NMR) analysis. The molecular weight of DNR was characterized by gel permeation chromatography (GPC). The results indicated good evidence for the formation of graft co-polymers in the presence of both initiators, AIBN or BPO. However, the amounts of grafted MMA/GMA on DNR backbone using BPO was higher than those on DNR backbone using AIBN.

Extraction and identification of fillers and pigments from pyrolyzed rubber and tire samples

1996 ◽  
Vol 54 ◽  
pp. 174-175
Author(s):  
P. Sadhukhan ◽  
J. B. Zimmerman
Keyword(s):  
Zinc Oxide ◽  
Electron Microscope ◽  
Carbon Black ◽  
Natural Rubber ◽  
Transmission Electron Microscope ◽  
Rolling Resistance ◽  
Synthetic Polymers ◽  
Nitrogen Atmosphere ◽  
Transmission Electron ◽  
Curing Agents

Rubber stocks, specially tires, are composed of natural rubber and synthetic polymers and also of several compounding ingredients, such as carbon black, silica, zinc oxide etc. These are generally mixed and vulcanized with additional curing agents, mainly organic in nature, to achieve certain “designing properties” including wear, traction, rolling resistance and handling of tires. Considerable importance is, therefore, attached both by the manufacturers and their competitors to be able to extract, identify and characterize various types of fillers and pigments. Several analytical procedures have been in use to extract, preferentially, these fillers and pigments and subsequently identify and characterize them under a transmission electron microscope.Rubber stocks and tire sections are subjected to heat under nitrogen atmosphere to 550°C for one hour and then cooled under nitrogen to remove polymers, leaving behind carbon black, silica and zinc oxide and 650°C to eliminate carbon blacks, leaving only silica and zinc oxide.

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