Effect of graphene treated with cyclohexyl diamine by diazonium reaction on cure kinetics, mechanical, thermal, and physical properties of natural rubber/graphene nanocomposite foam

2018 ◽  
Vol 40 (S2) ◽  
pp. E1766-E1776 ◽  
Author(s):  
Pollawat Charoeythornkhajhornchai ◽  
Chavakorn Samthong ◽  
Anongnat Somwangthanaroj
Keyword(s):  
Natural Rubber ◽  
Physical Properties ◽  
Cure Kinetics ◽  
Graphene Nanocomposite ◽  
Nanocomposite Foam ◽  
Diazonium Reaction

Effect of azodicarbonamide on microstructure, cure kinetics and physical properties of natural rubber foam

2016 ◽  
Vol 53 (3) ◽  
pp. 287-303 ◽  
Author(s):  
Pollawat Charoeythornkhajhornchai ◽  
Chavakorn Samthong ◽  
Kanoktip Boonkerd ◽  
Anongnat Somwangthanaroj
Keyword(s):  
Natural Rubber ◽  
Physical Properties ◽  
Bubble Size ◽  
Cure Kinetics ◽  
Expansion Ratio ◽  
Gas Content ◽  
Rubber Matrix ◽  
Volumetric Expansion ◽  
Blowing Agent ◽  
Amine Fragment

The effect of azodicarbonamide as chemical blowing agent on the morphology, cure kinetics and physical properties of natural rubber foam is investigated. From the morphology, when the amount of chemical blowing agent increases from 3 to 4 phr, the bubble size in the rubber matrix slightly decreases due to the increase of vulcanization reaction rate from the presence of amine fragment species as by-products from the decomposition of azodicarbonamide. The coalescence between bubbles is observed in the specimen with 5 and 6 phr of azodicarbonamide owing to high gas content in the rubber matrix. Moreover, the scorch time slightly reduces and cure rate increases as a function of azodicarbonamide content. The autocatalytic model can be used to explain the curing reaction and mechanism of this natural rubber foam. Furthermore, the activation energy (Ea) directly relates to the bubble size and microvoid structure of natural rubber foam. When compared with the vulcanized natural rubber without adding chemical blowing agent, it is found that the bulk density of natural rubber foam significantly decreases and the volumetric expansion ratio of natural rubber foam increases at high content of chemical blowing agent. Moreover, natural rubber foam at 4 phr of azodicarbonamide exhibits the lowest thermal expansion coefficient due to the smallest bubble size with less coalescence.

Relation between Molecular Weights and Physical Properties of Rubber Fractions

1941 ◽  
Vol 14 (3) ◽  
pp. 580-589 ◽  
Author(s):  
G. Gee ◽  
L. R. G. Treloar
Keyword(s):  
Molecular Weight ◽  
Natural Rubber ◽  
Physical Properties ◽  
High Molecular Weight ◽  
Elastic Properties ◽  
Elastic Material ◽  
Experimental Results ◽  
Molecular Weights ◽  
High Elasticity ◽  
Latex Rubber

Abstract As high elasticity is a property possessed only by substances of high molecular weight, it is of interest to enquire into the relation between the elastic properties of a highly elastic material such as rubber and its molecular weight. An investigation on these lines has been made possible through the work of Bloomfield and Farmer, who have succeeded in separating natural rubber into fractions having different average molecular weights. The more important physical properties of these fractions have been examined with the object of determining which of the properties are dependent on molecular weight and which are not. Fairly extensive observations were made on the fractions from latex rubber referred to as Nos. 2, 3 and 4 by Bloomfield and Farmer, and some less extensive observations were carried out on the less oxygenated portion of fraction No. 1 obtained from crepe rubber (called hereafter 1b) . Before considering these experimental results, and their relation to the molecular weights of the fractions, it will be necessary to refer briefly to the methods used for the molecular-weight determinations, and to discuss the significance of the figures obtained.

Evaluation of Cadmould Software to Simulate the Filling Phase of a Natural Rubber Compound in Injection Moulding Process

2013 ◽  
Vol 747 ◽  
pp. 571-574 ◽  
Author(s):  
Zulkifli Mohamad Ariff ◽  
T.H. Khang
Keyword(s):  
Natural Rubber ◽  
Injection Moulding ◽  
Input Data ◽  
Cure Kinetics ◽  
Rubber Compound ◽  
Moulding Process ◽  
Related Data ◽  
Mould Filling ◽  
Injection Moulding Process ◽  
Material Input

The possibility of using Cadmould software to simulate the filling behaviour of a natural rubber compound during an injection moulding process was investigated. For the simulation process, the determination of required material input data involving the rheological and cure kinetics data of the designed rubber compound were conducted. It was discovered that the acquired data were able to function as reliable material input data as they were comparable with related data available in the Cadmould software materials database. Verification of the simulated filling profiles by experimental short shots specimens showed that the Cadmould Rubber Package was able to predict the realistic filling behaviour of the formulated natural rubber compound inside the mould cavity when the measured material data were utilized. Whereas, the usage of available material database from the software failed to model the mould filling progression of the intended natural rubber compound.

Koroseal, a New Plastic. Some Properties and Uses

1935 ◽  
Vol 8 (4) ◽  
pp. 641-654
Author(s):  
S. L. Brous ◽  
W. L. Semon
Keyword(s):  
Natural Rubber ◽  
Physical Properties ◽  
Natural Product ◽  
Organic Materials ◽  
Linear Polymers ◽  
Independent Source ◽  
Historical Treatise ◽  
The Many ◽  
Marked Resistance ◽  
Modern Industry

Abstract Rubber has found its widest use in industry because its properties can be altered and improved by compounding and cure to give strong, flexible, resilient products which are resistant to abrasion, impervious to fluids, electrically insulating, and relatively inert chemically. For such other desirable characteristics as resistance to oils and solvents, and freedom from attack by air, sunlight, and oxidizing materials, skillful compounding has brought marked improvements, but even better properties are needed to meet the demands of modern industry. The search for synthetic rubbers has been stimulated not merely by the desire for an economically independent source of supply, but also with the hope that there might be obtained materials having properties superior to the natural product. Whitby and Katz (4) have published a comprehensive historical treatise dealing with the development of numerous synthetic rubbers which have appeared in the last few years. It has been believed that linear polymers obtained from dienes hold most promise for the preparation of rubber-like materials. Carothers (1) has studied the relation between the structure of dienes and the types of polymerization products which may be obtained therefrom. On the basis of these data he inferred that, from the standpoint of their polymerization products, the best dienes will be of the type CH2:CXCH:CH2, in which X is an activating group other than alkyl or aryl. In general it has been found that there may be obtained polymerization products with physical properties equal to, or often superior to those of natural rubber, and with marked resistance to the action of solvents and chemicals. Among the many types of organic materials which will polymerize, the vinyl compounds only recently have been modified suitably to yield commercial rubber-like materials.

Influences of surfactant content and type on physical properties of natural rubber/organoclay nanocomposites

2012 ◽  
Vol 19 (7) ◽  
Author(s):  
Chalermpan Keawkumay ◽  
Kasama Jarukumjorn ◽  
Jatuporn Wittayakun ◽  
Nitinat Suppakarn
Keyword(s):  
Natural Rubber ◽  
Physical Properties

Green preparation and physical properties of maleated sulfur-prevulcanized natural rubber

2012 ◽  
Vol 69 (6) ◽  
pp. 635-647 ◽  
Author(s):  
Sa-Ad Riyajan ◽  
Isara Intharit ◽  
Pramuan Tangboriboonrat
Keyword(s):  
Natural Rubber ◽  
Physical Properties

Characterization of Ground Rubber Tire and its Effect on Natural Rubber Compound

2000 ◽  
Vol 73 (5) ◽  
pp. 902-911 ◽  
Author(s):  
Amit K. Naskar ◽  
S. K. De ◽  
A. K. Bhowmick ◽  
P. K. Pramanik ◽  
R. Mukhopadhyay
Keyword(s):  
Natural Rubber ◽  
Physical Properties ◽  
Rubber Compound ◽  
Rubber Tire ◽  
Ground Rubber

Abstract Ground rubber tire (GRT) particles of different sizes were characterized and the effect of these particles in a natural rubber (NR) compound was studied. It is found that smaller particles contain less polymer, but have higher amounts of fillers and metals with respect to polymer. NR compound containing smaller GRT particles shows better physical properties, but poorer aging characteristics.

Oxidative Aging of Natural Rubber Vulcanizates. Part III. Crosslink Scission in Monosulfidic Networks

1969 ◽  
Vol 42 (3) ◽  
pp. 924-935 ◽  
Author(s):  
T. Colclough ◽  
J. I. Cunneen ◽  
G. M. C. Hrggins
Keyword(s):  
Natural Rubber ◽  
Physical Properties ◽  
Chemical Structure ◽  
Spectroscopic Methods ◽  
Chemical Probes ◽  
Conjugated Diene ◽  
Strain Measurements ◽  
Oxidative Aging ◽  
Tert Butyl Hydroperoxide ◽  
Natural Rubber Vulcanizates

Abstract A natural rubber vulcanizate containing almost entirely monosulfidic crosslinks was oxidized in oxygen and with tert-butyl hydroperoxide. The changes in physical properties due to oxidation were followed by stress—strain measurements, and the changes in chemical structure were investigated with chemical probes, and by spectroscopic methods. The results show that when the oxidized vulcanizates are heated at 75° C, the monosulfidic crosslinks are broken, that crosslinks containing two sulfur atoms are formed, and that conjugated diene and triene structures are introduced into the main polyisoprene chains.

Sign in / Sign up

Export Citation Format

Share Document