Polymer irradiation
AssigneeNational Research Development Corporation
InventorsIan M. Ward, Denis W. Woods, Walter K. Busfield
Life of this patent
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Abstract
A process for the preparation of an oriented homo- or co-polyalkene material of improved strain rate sensitivity, which process comprises subjecting the oriented homo- or co-polyalkene material having a weight average molecular weight (M.sub.w).ltoreq.350,000, a number average molecular weight (M.sub.n).gtoreq.5,000, and a 2% secant modulus of at least 10 GPa at a strain rate of 2.times.10.sup.-5 sec.sup.-1 to a high energy irradiation of a dosage of at least 1 Mrad and not more than 60 Mrads at an elevated temperature in vacuo or in an inert or sensitizing atmosphere.
Claims17
A process for the preparation of an oriented homo-polyethylene or co-polyethylene of improved strain rate sensitivity, which process comprises:
- (1) Providing the solid homo- or copolyethylene;
- (2) Orienting the molecules of said homo- or co-polyethylene to produce a highly oriented product having a 2% secant modulus of at least 10 GPa at a strain rate of 2.times.10.sup.-5 sec.sup.-1 ;
- (3) Subjecting the oriented product to a high energy irradiation of a dosage of at least 1 Mrad and not more than 60 Mrads at a temperature of from 30.degree. C. to 140.degree. C. in vacuo or in an inert or sensitizing atmosphere, wherein said homo- or co-polyethylene has a weight average molecular weight (M.sub.w) less than or equal to 350,000, a number average molecular weight of (M.sub.n) greater than or equal to 5,000.
A process for the preparation of an oriented homo-polyethylene or co-polyethylene of improved strain rate sensitivity, which process comprises:
- (1) Melt spinning the homo- or co-polyethylene to provide melt spun fibers of filaments;
- (2) Orienting the molecules of said homo- or co-polyethylene to produce fiber or filaments having a 2% secant modulus of at least 10 GPa at a strain rate of 2.times.10.sup.-5 sec.sup.-1 ;
- (3) Subjecting the oriented fiber or filament to a high energy irradiation of a dosage of at least 1 Mrad and not more than 60 Mrads at a temperature of from 30.degree. C. to 140.degree. C. in vacuo or in an inert or sensitizing atmosphere, wherein said homo- or co-polyethylene has a weight average molecular weight (M.sub.w) less than or equal to 350,000, a number average molecular weight of (M.sub.n) greater than or equal to 5,000.
Dependencies are inferred from the claim text.