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Water swelling polyisoprene

The theory proposed for equilibrium swelling and diffusion is based on the assun tlon that the hydrophilic impurities are present in particulate form and are dispersed throughout the rubber. The precise nature of this impurity in natural rubber is not known so it was decided to make a model rubber by adding 0.17. of a hydrophilic Impurity (sodium chloride) to a solution polymerised synthetic rubber (cis-polyisoprene) Ich is chemically the same as natural rubber. Using this model rubber it is possible to check the theory more precisely since both the nature and concentration of the hydrophilic lgq>urlty in the model rubber are known. It is proposed that the water diffuses through the rubber and forms droplets of solution inside the rubber where there are particles of the hydrophilic impurity thereby causing a non-uniform distribution of water in the rubber. The... [Pg.375]

Nonpolar polymers (polyisoprene, polybutadiene) mix infinitely with alkanes (hexane, oetane, ete.) but do not mix with sueh polar liquids as water and aleohols. Polar polymers (eellulose, polyvinylalcohol, ete.) do not mix with alkanes and readily swell in water. Polymers of the average polarity dissolve only in liquids of average polarity. For example, polystyrene is not dissolved or swollen in water and alkanes but it is dissolved in aromatie hydrocarbons (toluene, benzene, xylene), methyl ethyl ketone and some ethers. Polymethylmethacrylate is not dissolved nor swollen in water nor in alkanes but it is dissolved in dichloroethane. Polychloroprene does not dissolve in water, restrictedly swells in gasoline and dissolves in 1,2-dichloroethane and benzene. Solubility of polyvinylchloride was considered in terms of relationship between the size of a solvent molecule and the distance between polar groups in polymer. ... [Pg.127]

Nonpolar polymers (polyisoprene, polybutadiene) mix infinitely with alkanes (hexane, octane, etc.) but do not mix with such polar liquids as water and alcohols. Polar polymers (cellulose, polyvinylalcohol, etc.) do not mix with alkanes and readily swell in water. [Pg.143]


See other pages where Water swelling polyisoprene is mentioned: [Pg.262]    [Pg.269]    [Pg.269]    [Pg.367]    [Pg.43]    [Pg.809]   
See also in sourсe #XX -- [ Pg.30 , Pg.32 ]




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