Production of sheets of polythene modified by the polystyrene

摘要

A process for the production of sheet materials comprises calendering a composition that has been produced by exposing polyethylene in comminuted form to contact with sufficient styrene to form a swollen material containing 10%-35% by weight of styrene, and polymerizing the styrene in the swollen material under the influence of heat and of a free-radical producing catalyst. The polyethylene may be in the form of granules, chips or flakes and may be agitated with the styrene at elevated temperatures below that at which appreciable polymerization of the styrene occurs. The catalyst may be benzoyl peroxide, tertiary butyl hydroperoxide, or a , a 1-azodiisobutyronitilre. The product may be masticated, optionally with pigments, dyestuffs and lubricants, e.g. zinc stearate, calcium stearate and stearic acid, before being fed to the calender. The products may be used as tablecloths, shower curtains, screens and awnings, and, after treatment, e.g. with chlorosulphonic acid, to introduce groups confering ion-exchange properties, e.g. sulphonic acid, amino and quaternary ammonium groups, as ion-exchange membranes. Specification 863,862 is referred to.