| 摘要 |
Polyvinyl chloride compositions comprise 5 to 98 weight per cent of polyvinyl chloride prepared by polymerization of vinyl chloride at above 40 DEG C. and 2 to 95 weight per cent of polyvinyl chloride prepared by polymerization of vinyl chloride below 0 DEG C. The polymers may be prepared in bulk, solution, suspension or emulsion at temperatures above 40 DEG C., e.g. 40 DEG to 80 DEG C., and below 0 DEG C., e.g. 0 DEG to - 30 DEG C. The compositions may be made into foils, films, filaments and fibres, e.g. by spinning from solutions in tetrahydrofuran, cyclohexanone, dimethyl formamide, propylene oxide, cyclopentanone, carbon disulphide/acetone mixtures, perchlorethylene/acetone mixtures, benzene/acetone mixtures or carbon tetrachloride/benzene/acetone mixtures, or from suspensions in trichlorethylene, tetrachlorethane, chloroform, methylene chloride, acetone, methyl ethyl ketone, benzene, toluene, ethyl benzene, xylene, dioxane, ethyl acetate or methyltetrahydrofuran. Examples describe mixtures of polyvinyl chlorides prepared by polymerization in water in the presence of polyvinyl alcohol and (A) lauroyl peroxide at 60-61 DEG C., (B) and (C) sodium chloride, potassium acid phthalate, sodium hydroxide, chloroform, sodium peroxide and trichloracetyl chloride at -10 DEG C., and (D) sodium chloride, potassium acid phthalate, sodium peroxide and trichloracetyl peroxide.
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