Rubber-like materials

Handbook of elastomers , A.K. Bhowmick and H.L. Stephens Marcel Dekker (1988) Series Plastics Engineering, Volume 19 ISBN 0824778006. This handbook systematically addresses the manufacturing techniques, properties, processing, and applications of rubbers and rubber-like materials. The Handbook of Elastomers provides authoritative information on natural rubbers, synthetic rubbers, liquid rubbers, powdered rubbers, rubber blends, thermoplastic elastomers, and rubber-based composites— offering solutions to many practical problems encountered with rubber materials. 

This review will highlight various aspects of electron beam processing of rubber. In addition, other rubber-like materials and non-EB techniques have also been briefly discussed for comparison. 

Another product EPDM is a rubber-like material. It comes in 60-mil thickness in 100 ft by 61-1/2 in. rolls. EPDM also comes in 45-mil thickness in 25 ft by 60 ft rolls. This product has gained popularity as a ground cover in crawlspaces because of its durability qualities. 

Rubber-like materials now superseding the traditional mastics and putties used in the building industry. Such sealants (also termed mastics) are based on butyl rubber, liquid polysulphides, silicone rubbers, polybutylene, nitrile rubbers and plasticised vinyl polymers. SEBS... 

Mo2(0R)6 compounds in hydrocarbon solvents rapidly polymerize acetylene to a black metallic-looking form of polyacetylene. Propyne is polymerized to a yellow powder, while but-2-yne yields a gelatinous rubber-like material (45). The detailed nature of these polymers is not yet known and the only molybdenum containing compounds recovered from these polymerization reactions were the Mo2(0R)6 compounds. When the reactions were carried out in the presence of pyridine/hexane solvent mixtures, simple adducts Mo2(0R)6(py)2(ac) were isolated for R = i-Pr and CH2-t-Bu, and ac = HCCH, MeCCH and MeCCMe (45,46). 

Barquins, M. 1992. Adherence, friction and wear of rubber-like materials. Wear... 

A mixture of ammonium perchlorate (AP NH4CIO4) and a hydrocarbon polymer (BDR) used as fuel binder forms an AP pyrolant that generates white smoke when it burns in a humid atmosphere. The polymer acts as a binder of the AP particles to form a rubber-like material. When the AP pyrolant burns, the AP particles oxidize the hydrocarbon polymer according to ... 

Kraton, the yellow rubber-like material often found on the bottom of running shoes, is a copolymer whose structural information is known. It is formed from a group of styrene units, i.e., a block of polystyrene, attached to a group of butadiene units, or a block of... 

With this condition, there are a great many possible choices for the form of W as a function of Our ultimate purpose in the phenomenologic study of rubber elasticity is to find out its form applicable for an accurate and coherent description of the elastic behavior of rubber-like materials under various modes of deformation. We may use /j, J2, and J3 for the set of /<, which are defined by... 

Rivlin and Saunders11 suggested from their biaxial extension experiments on vulcanized natural rubber that the form of W for rubber-like material would be... 

The behaviour of rubber-like material when stretched. J. Colloid Sci. 1, 235 (1946). 

This unusual behavior results from unsolvated crystalline regions in the PVC that act as physical cross-links. These allow the PVC to accept large amounts of solvent (plasticizers) in the amorphous regions, lowering its Tg to well below room temperature, thus making it rubbery. PVC was, as a result, the first thermoplastic elastomer (TPE). This rubber-like material has stable properties over a wide temperature range. 

Spezialsprengelatine (Swiss). A name given by Stettbacher to low-freezing, powerful Dynamites manufd at Isleton and used in the construction of the Jungfrau tunnels. Essentially, these expls were based on Blasting Gelatin in which part of the NG was replaced by aromatic nitrocompds. One such expl had a d of 1.58g/cc and was a reddish-yellow, rubber-like material Ref Naoum, Expls (1927), 113... 

Elastomer is a term used to describe a wide range of soft materials used in fuel systems. One of the best examples is the common O-ring—usually made from a soft, rubber-like material— that depends on its ability to deform under pressure to perform properly. The most common job for elastomers in fuel systems is to prevent leaks from fittings and joints. 

D.R. Burfield, Proceedings of the International Conference on Rubbers and Rubber-like Materials, Jamshedpur, India, 1987, Paper No.G-1, p.419. 

A comparatively new group of materials— thermoplastic elastomers or thermoplastic rubbers —combines the ease of processing of thermoplastics with qualities of traditional vulcanized rubbers, especially elasticity. Because of convenience in processing there is much interest too in blends of plastics with elastomers, which may be modified by the inclusion of filler or glass fibre. As an example, a rubber-like material that can be processed as a thermoplastic can be made by blending and melt-mixing an ethylene-propylene rubber with polypropylene. The use of such blends may be helpful when there are needs to reclaim and re-process material, and in order to obtain products with qualities intermediate between those of the main components of the blends. 

Rubber and rubber-like materials are systems of molecules—monomers or mers—that are subject to two types of interactions. The first type are covalent interactions that tie monomers into long chains, which are typically 100 or more mers long. The second type are nonbonded interactions, which occur between pairs of mers that are not covalently bonded to each other. We are concerned here with an examination of how nonbonded interactions are generally treated in theoretical studies of rubber elasticity and with the limitations of this approach. 

Although a key characteristic of the mechanical behavior of rubber-like materials is their ability to undergo large elastic deformations, we will present here some important results from the theory of linear elasticity [1], which is valid only for small deformations. These serve our present purposes better than the nonlinear theory, because of their simpler character and physical transparency. 

The moderate random chlorination of polyethylene suppresses crystallinity and yields chlorinated polyethylene elastomer (CPE), a rubber-like material that can be crosslinked with organic peroxides. The chlorine (Cl) content is in the range of 36 to 42%, compared to 56.8% for PVC. Such elastomer has good heat and oil resistance. It is also used as a plasticizer for PVC. They provide a very wide range of properties from soft/elastomeric too hard. They have inherent oxygen and ozone resistance, resist plasticizers, volatility, weathering, and compared to PEs have improved resistance to chemical extraction. Products do not fog at high temperatures as do PVCs and can be made flame retardant. 

If you take a polymer like atactic polystyrene that is incapable of crystallizing and heat it, it first softens, then becomes a tacky, rubber-like material and finally takes... 

Parkes Absorbent for Nitroglycarin. Materials patented in 1898 by Parkes, manufd by Chem-ische Fabrik at Winkel-on-Rhine, Ger, for use in Dynamites as absorbents for NG in lieu of the previously used kieselguhr. The absorbents were rubber-like materials, prepd by the action of sulfur chloride, S2CI2, on vegetable oils. It was claimed at the time that Dynamites prepd with Parkes absorbent were so insensitive, they could be used for loading shells... 

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