Irradiation Conversion of Thermoplastic to Thermoset Polymers

Abstract

Disclosed is a radiation-crosslinkable thermoplastic polymer composition, a process for the preparation thereof, an angioplasty balloon and a medical catheter made using such a composition. The composition contains a reactive monomer cross-linker facilitates cross-linking of the reaction product upon contact of the cross-linker-containing composition with energy from a radiation source.

1 . A radiation cross-linkable medical angioplasty balloon or radiation cross-linkable medical catheter made from a thermoplastic cross-linkable composition, said thermoplastic cross-linkable composition comprising:
 (a) a thermoplastic polymer which is the reaction product of an aromatic polyisocyanate and a polyahl; and   (b) a monomer crosslinker selected from the group consisting of methacrylate monomer crosslinkers and acrylate monomer crosslinkers, for conversion of at least a portion of said thermoplastic polymer to convert said portion from a thermoplastic to a thermoset state upon irradiation of said composition with energy from a radiation source.   
   
   
       2 . A radiation cross-linked medical angioplasty balloon or radiation cross-linked medical catheter made by irradiating the radiation cross-linkable medical angioplasty balloon or radiation crosslinkable medical catheter of  claim 1  with energy from a radiation source. 
   
   
       3 . The radiation cross-linkable medical angioplasty balloon or radiation cross-linkable medical catheter of  claim 1 , wherein said thermoplastic polymer is a thermoplastic elastomer. 
   
   
       4 . The radiation cross-linkable medical angioplasty balloon or radiation cross-linkable medical catheter of  claim 1 , wherein said thermoplastic polymer is a block copolymer containing hard and soft segments. 
   
   
       5 . The radiation cross-linked medical angioplasty balloon or radiation cross-linked medical catheter of  claim 2 , wherein said energy is in the form of radiation selected from the group consisting of beta particles, gamma rays, ultraviolet radiation, electron beam radiation, and combinations thereof. 
   
   
       6 . The radiation cross-linkable medical angioplasty balloon or cross-linkable medical catheter of  claim 1 , wherein said monomer cross-linker is selected from the group consisting of trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, tetraethylene glycol dimethacrylate and combinations thereof. 
   
   
       7 . A radiation cross-linked medical angioplasty balloon or radiation cross-linked medical catheter made from a cross-linked composition, wherein said cross-linked composition is produced by irradiating a cross-linkable composition comprising:
 (a) a thermoplastic polymer which is the reaction product of an aromatic polyisocyanate and a polyahl; and   (b) a monomer crosslinker selected from the group consisting of methacrylate monomer crosslinkers and acrylate monomer crosslinkers, meta-phenylene dimaleimide, and combinations thereof; said monomer crosslinker present in said composition in an amount sufficient to cross-link at least a portion of said thermoplastic polymer to convert said portion from a thermoplastic to a thermoset state upon irradiation of said composition with energy from a radiation source.   
   
   
       8 . The radiation cross-linked medical angioplasty balloon or radiation cross-linked medical catheter of  claim 7 , wherein said thermoplastic polymer is a thermoplastic elastomer. 
   
   
       9 . The radiation cross-linked medical angioplasty balloon or radiation cross-linked medical catheter of  claim 7 , wherein said thermoplastic polymer is a block copolymer containing hard and soft segments. 
   
   
       10 . The radiation cross-linked medical angioplasty balloon or radiation cross-linked medical catheter of  claim 7 , which is produced by irradiating said cross-linkable composition with energy in the form of radiation selected from the group consisting of beta particles, gamma rays, ultraviolet radiation, electron beam radiation, and combinations thereof. 
   
   
       11 . The radiation cross-linked medical angioplasty balloon or radiation cross-linked medical catheter of  claim 7 , wherein said monomer crosslinker is selected from the group consisting of trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, tetraethylene glycol dimethacrylate and combinations thereof.