Claims
- 1. A process for improving the thermal, optical and/or mechanical properties of a polymer in the absence of a nucleating agent which comprises the steps of:
- a) forming a melt of a polymer; and
- b) subjecting said melt, prior to molding to an effective shear rate of greater than about 100 sec.sup.-1 for time sufficient to improve the thermal, optical and/or mechanical properties of said polymer; wherein said polymer is selected from one or more of the following groups of polymers;
- --NHCORCONHR'-- (i)
- in which R is an alkylene group of at least two carbon atoms, and R' is selected from R and phenyl groups;
- (ii) the copolyamide of 30% hexamethylene diammonium isophthalate and 70% hexamethylene diammonium adipate, the copolyamide of up to 30% bis-(p-amidocyclohexyl)methylene, and terephthalic acid and caproactam, poly (hexamethylene adipamide), poly(4aminobutyric acid), poly(7-amino-heptanoic acid), poly(8 aminooctanoic acid), poly(6-aminohexanoic acid), poly((bis(4-aminocyclohexy)methane-1.10-decanedicarboxamide)), poly(peperazine sebacamide), poly(11-amino undecanoic acid), poly(12-aminododecanoic acid), polyhexamethylene isophthalamide, poly(9-aminononanoic acid), polycaproamide, or combinations thereof; and
- (iii) poly(ethylene terephthalate), poly(cyclohexylenedimethylene, terephthalate), poly(ethylene dodecate, poly(butylene terephthalate), poly(ethylene(2,7-naphthalate), poly(glycolic acid), poly(ethylene succinate), poly(ethylene adipate), poly(ethylene sebacate), poly(decamethylene azelate), poly(decamethylene adipate), poly(decamethylene sebacate), poly(dimethylpropiolactone), poly(ethylene oxybenzoate), poly(ethylene isophthalate), poly(tetramethylene terephthalate, poly(hexamethylene terephthalate), poly(decamethylene terephthalate), poly(1,4-cyclohexylidene dimethyleneterephthalate), and poly(1,4-cyclohexylidene dimethylene terephthalate.
- 2. A process according to claim 1 wherein said polymer is a polyester.
- 3. A process according to claim 3 wherein said polyester is polyethylene terephthalate.
- 4. A process according to claim 1 wherein said polyamide is poly(6-aminohexanoic acid) or poly(hexamethylene adipamide).
- 5. A process according to claim 1 wherein said polyamide is poly(6-aminohexanoic acid).
- 6. A process according to claim 1 wherein said polymer melt is subjected to a shear by mechanical means.
- 7. A process according to claim 6 wherein said polymer melt is subjected to a shear by extruding said melt through an extruder at a temperature equal to or greater than the melting point of said polymer.
- 8. A process according to claim 1 wherein said shear rate is from greater than about 100 sec.sup.-1 to about 20,000 sec.sup.-1.
- 9. A process according to claim 8 wherein said shear rate is from greater than about 100 sec.sup.-1 to about 10,000 sec.sup.-1.
- 10. A process according to claim 9 wherein said shear rate is from about 1000 sec.sup.-1 to about 10,000 sec.sup.-1.
- 11. A process according to claim 1 wherein said polymer melt is subject to a shear at least twice, at least one of which is at an effective shear rate.
- 12. A polymer processed according to the process of claim 1.
- 13. A process for forming a molded article having improved optical, mechanical and/or thermal properties, said process comprising molding the polymer of claim 12 to form said molded article.
- 14. A molded article formed in accordance with the process of claim 13.
- 15. The process according to claim 1 wherein the polymer is selected from the group consisting of poly(ethylene terephthalate), poly(butene terephthalate) and poly(1,4-cyclohexane dimethylene terephthalate).
- 16. The process according to claim 1 wherein R' and R are the same.
- 17. The process according to claim 1 wherein R' and R are different.
- 18. A process according to claim 1 wherein in the formula
- --NHCORCONHR'-- (1)
- R is an alkylene group of having from 2 to about 10 carbon atoms; and R' is selected from R and phenyl groups.
- 19. A process according to claim 11 wherein said first shear is an effective shear rate of greater than about 100 sec.sup.-1.
- 20. The process of claim 19 wherein the second shear is effected by molding.
- 21. The process of claim 20 wherein said molding is injection molding.
- 22. The process of claim 20 wherein said molding is injection, compression on extrusion molding.
RELATED APPLICATION
This application is a continuation-in-part application of U.S. patent application Ser. No. 064,364, filed Jun. 22, 1987, now abandoned.
US Referenced Citations (9)
Non-Patent Literature Citations (3)
Entry |
A. Ajji et al. "Chain Entanglement and Viscoelastic Properties of Molten Polymers" Jrnl of Polymer Science: Part B: Polymer Physics, vol. 24/1983-90 (1986). |
R. Schertzer et al. "Shear and Thermal History Effects in Polypropylen Melts" Jrnl of Applied Science, vol. 31, 809-821 (1986). |
A. Rudin et al. "Shear Modification of Polymers" Polymer Engineering and Science, Mid-Jun. 1983, vol. 23, No. 8. |
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
64364 |
Jun 1987 |
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