Cis-Polybutadiene rubber

Kuleznev, V. N., Klykova, V. D., and Wasiltschenko, E. I., Influence of the solubility of oligoesteracrylates in cis-polybutadiene rubber (SKD) on the strength properties of vulcanizates. Colloid. Zhur, 38, 1976 (Russian). 

The cis-polybutadiene, cis-polyisoprene, and ethylene-propylene rubbers are close duphcates of natural rubber. The newer eth)aene-propylene rubbers (EPR) have excellent resistance to heat and oxidation. 

The most spectacular case of products arising from a catalyst invention is that of the stereospecific hydrocarbon polymers made possible by the Ziegler-Natta work on aluminum alkyl/transition metal halide combinations around 1950. Until these catalysts existed, polypropylene, polyiso-prene, and cis-polybutadiene could not be made, and linear polyethylene could not be made cheaply. For each of these products, very large investments were needed in big plants and in market development before they were competitive with the established, big thermoplastics and rubbers. Entrance fees ran into tens of millions of dollars. 

The properties of impact polystyrene can be improved by simultaneous grafting and crosslinking upon rubber. Changing cis-polybutadiene into trans-polybutadiene and eliminating the 1,2-vinyl configuration through radiation are discussed by Parkinson. 

Hydrocarbon - An organic chemical compound containing the elements carbon and hydrogen. Aliphatic hydrocarbons are straight chain compounds and aromatic hydrocarbons are based on the cyclic or benzene ring. They may be gaseous, (methane, ethylene, butadiene) liquid (hexane, benzene) or solid (natural rubber, naphthalene, cis-polybutadiene). 

The new absorptions in the spectra of crosslinked rubber are assigned on the basis of 13C solution NMR chemical shifts for a variety of model compounds, such as pentenes and mono-, di- and tri-sulfidic compounds, by using the 13C chemical shift substituent effect. From the calculated values for particular structural units, the experimental spectra of a sulfur vulcanized natural rubber 194,195,106), natural rubber cured by accelerated sulfur vulcanization 197 y-irradiation crosslinked natural rubber198 and peroxide crosslinked natural rubber and cis-polybutadiene 193 1991 are assigned. 

Unlike PE, many polymers have ahigh concentration of the internal C=C bonds. The carboxidation of such materials led to quite unexpected results. This can be illustrated by the carboxidation of cis- 1,4-polybutadiene rubber (poly-BD) studied in detail by Dubkov et al. [180], The concentration of C=C bonds in this rubber is 250 bonds per 1000 carbon atoms. Possible oxygen content in the poly-BD can reach up to 23 wt%, if all C=C bonds are transformed into the C=0 groups. 

Since compounds of the type XVII have shown comparable activity in a number of systems including cis-polybutadiene, styrene-butadiene rubber, and ethylene-propylene rubber, they have some commercial promise, and development work on these compounds is continuing. Nevertheless, they are not completely nondiscoloring, and in certain applications, particularly carboxylated styrene-butadiene latex films, yellow discoloration caused by the antioxidant is a serious drawback. We therefore turned our attention to ortho-linked compounds derived from 2,4-dialkylphenols. 

Chief among the synthetic elastomers is SBR, a copolymer of butadiene (75%) and styrene (25%) produced under free-radical conditions it competes with natural rubber in the main use of elastomers, the making of automobile tires. All-cis polybutadiene and polyisoprene can be made by Ziegler-Natta polymerization. 

Knauf, T.F. Osman, A. Process for cis-Polybutadiene Production with Reduced Gel Formation. U.S. Patent 5,397,851,, Mar 14, 1995 Polysar Rubber. 

The effects of HAF black on the stress relaxation of natural rubber vulcanizates was studied by Gent (178). In unfilled networks the relaxation rate was independent of strain up to 200% extension and then increased with the development of strain induced crystallinity. In the filled rubber the relaxation rate was greatly increased, corresponding to rates attained in the gum at much higher extensions. The results can be explained qualitatively in terms of the strain amplification effect In SBR, which does not crystallize under strain and in cis-polybutadiene, vulcanizates of which crystallize only at very high strains, the large increase in relaxation rate due to carbon black is not found (150). 

Polyblends with Soft Matrix and Soft or Rigid Dispersed Phase. Polyblends in which both components are soft are mixtures of various elastomers. For example, treads of automobile tires are made of a polyblend of SBR with either natural rubber or cis-polybutadiene. 

Soft Soft Longer wear Natural rubber + cis-polybutadiene... 

SBR etc., yet it has been covulcanized with those rubbers to provide useful materials (4). In this work, we have found that poly(isobutylene-co-0-pinene) with 10 mole% unsaturation can also be cocured with a high cis-1,4-polybutadiene rubber. Covulcanization has been demonstrated by an experiment in which poly(isobutylene-co-0-pinene) plus cis-1,4-polybutadiene were mixed on a laboratory mill for 40 minutes, cured (30 minutes at 160°) and the vulcanizate extracted with n-hexane (24 hours at 65°). The fact that the amount of extractables was 2% indicates a measure of covulcanization. The covulcanizate exhibited a tensile strength of 175 kg/cm2 and elongation at break of 300%. 

FIGURE 14.9 Percentage rebound recovery measured at 298 K, with balls made from (1) cis-polybutadiene, (2) synthetic cw-polyisoprene, (3) natural cw-polyisoprene, (4) ethylene-propylene copolymer, (5) styrene-butadiene (SBR), (6) /ran -polyisoprene, and (7) butyl rubber. 

Synonyms Atactic butadiene polymer BR Buta-1,3-diene Butadiene homopoiymer 1,3-Butadiene, homopolymer Butadiene oligomer Butadiene poiymer 1,3-Butadiene, poiymers Butadiene resin Butadiene rubber Poiy-1,3-butadiene cis-Poiybutadiene Polybutadiene latex Polybutadiene resin Polybutadiene rubber ClassiTication Polymer elastomer latex Empirical (C4H6) ... 

Fig. 6. The variation of the stress optical coefficient with cis content for 1,4-polybutadiene rubbers swollen with a number of solvents. The data include streaming birefringence data of Poddubnyi ct al. and of Phillipoff. (From Ref. 23.)...

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