National Research Development Corporation

Giancarlo Capaccio

Ian MacMillan Ward

Francis S Smith

A high modulus polymer material is produced by subjecting a crystallizable polymer to a thermal treatment under conditions such that the possibility that a given molecular chain is incorporated in more than one crystal lamella is substantially reduced and then attenuating the polymer at an imposed rate and temperature whereby substantially complete alignment of its molecules may be obtained.

Polymer materials

Oriented polymer material of high Young's modulus and low creep strain is provided by a process which comprises drawing polymer material having a weight average molecular weight greater than 150,000 and a ratio of weight average molecular weight to number average molecular weight greater than 5 at temperatures from 95.degree. C. to 140.degree. C. and at a rate such that the deformation ratio is greater than 18.

High modulus, low creep strain polyalkene polymer materials

A process for the production of a high modulus filament of polyethylene which comprises heating high density polyethylene to a temperature above its melting point, extruding the polymer to form a filament, subjecting the filament immediately after extrusion to a tension under such conditions that the filament is shaped without substantial orientation of its molecules, cooling the filament at a rate of cooling in excess of 15.degree. C. per minute, and drawing the filament to a high draw ratio.

Process for the continuous production of high modulus filament of

A high modulus polymer material is produced by subjecting a crystallisable polymer to a thermal treatment under conditions such that the possibility that a given molecular chain is incorporated in more than one crystal lamella is substantially reduced and then attenuating the polymer at an imposed rate and temperature whereby substantially complete alignment of its molecules may be obtained.

Process for the production of polymer materials

Oriented polymer material of high Young's modulus and low creep strain is provided by a process which comprises drawing polymer material having a weight average molecular weight greater than 300,000 and a ratio of weight average molecular weight to number average molecular weight greater than 5 at temperatures from 95.degree. C. to 140.degree. C. and at a rate such that the deformation ratio is greater than 18.

Process for high modulus polymeric materials

An oriented high density polyethylene polymer material having a weight average molecular weight of less than 200,000, a number average molecular weight of less than 20,000, a ratio of weight average molecular weight M.sub.w to number average molecular weight M.sub.n such that for M.sub.n &gt; 10.sup.4, M.sub.w /M.sub.n &lt; 8 and for M.sub.n &lt; 10.sup.4, M.sub.w /M.sub.n &lt; 20, and a Young's modulus greater than 3 .times. 10.sup.10 N/m.sup.2.

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Leeds, United Kingdom

Giancarlo Capaccio