Titanium dioxide catalyzed butadiene polymer based oxygen scavenging system

Abstract

A composition of matter having oxygen scavenging properties comprises a blend of a base polymer, a butadiene polymer, and titanium dioxide in an amount sufficient to catalyze reaction of oxygen with the butadiene polymer. In further aspects, methods for making the compositions herein and packaging film structures comprising the compositions herein, and packaging articles formed of the same, are also provided.

What is claimed is: 
     
         1 . A composition of matter having oxygen scavenging properties, comprising a blend of:
 a base polymer;   a butadiene polymer; and   titanium dioxide in an amount sufficient to catalyze reaction of oxygen with the butadiene polymer.   
     
     
         2 . The composition of  claim 1 , wherein the butadiene polymer comprises (i) a homopolymer of butadiene and/or (ii) a copolymer of butadiene. 
     
     
         3 . The composition of  claim 2 , wherein the copolymer of butadiene is a copolymer of butadiene and at least one monomer selected from the group consisting of isoprene, acrylonitrile, and styrene. 
     
     
         4 . The composition of  claim 1 , wherein the base polymer is ethyl cellulose. 
     
     
         5 . The composition of  claim 4 , wherein the composition is in a form selected from the group consisting of a solution cast film and a fibrous mat. 
     
     
         6 . The composition of  claim 5 , wherein the composition is prepared from a solvent mixture comprising the base polymer, the butadiene polymer, the titanium dioxide, and a solvent system, wherein the solvent system is selected from the group consisting a toluene/ethanol solvent system and an ethanol/water solvent system. 
     
     
         7 . The composition of  claim 4 , wherein the composition is prepared by a technique selected from the group consisting of solution casting and electrospinning. 
     
     
         8 . The composition of  claim 4 , wherein the composition is in the form of a fibrous mat having fibers with a diameter in the range of from about 0.3±0.1 microns to about 0.6±0.2 microns. 
     
     
         9 . The composition of  claim 4 , wherein the composition does not include a curing agent. 
     
     
         10 . The composition of  claim 1 , wherein the composition does not include a curing agent. 
     
     
         11 . The composition of  claim 1 , wherein the base polymer is a polyester. 
     
     
         12 . The composition of  claim 11 , wherein the polyester is polylactic acid (PLA). 
     
     
         13 . The composition of  claim 11 , wherein the composition is prepared by reactive melt extrusion of the polyester with the butadiene polymer and the titanium dioxide. 
     
     
         14 . The composition of  claim 1 , wherein the base polymer is a polyolefin. 
     
     
         15 . The composition of  claim 14 , wherein the polyolefin is low density polyethylene (LDPE). 
     
     
         16 . The composition of  claim 15 , further comprising a hydrocarbon wax for improving dispersion of the butadiene polymer in the low density polyethylene. 
     
     
         17 . The composition of  claim 14 , wherein the composition is prepared by melt blending. 
     
     
         18 . The composition of  claim 14 , wherein the polyolefin is linear low density polyethylene (LLDPE). 
     
     
         19 . The composition of  claim 1 , wherein the butadiene polymer is selected from the group consisting of unfunctionalized polybutadiene and a functionalized end group polybutadiene. 
     
     
         20 . The composition of  claim 19 , wherein the functionalized end group polybutadiene is selected from the group consisting of hydroxyl terminated polybutadiene (HTPB), epoxy terminated polybutadiene, and carboxy terminated polybutadiene. 
     
     
         21 . The composition of  claim 20 , wherein the functionalized end group polybutadiene is hydroxyl terminated polybutadiene having one or both of a relatively high trans content and a relatively low vinyl content. 
     
     
         22 . The composition of  claim 21 , wherein the hydroxyl terminated polybutadiene has a trans content of about 60%, a cis content of about 20%, and a vinyl content of about 20%. 
     
     
         23 . The composition of  claim 1 , wherein the titanium dioxide is present in an amount sufficient to catalyze reaction of oxygen with the butadiene polymer wherein moisture is not necessary to activate the reaction. 
     
     
         24 . The composition of  claim 1 , wherein the titanium dioxide is present in an amount sufficient to catalyze reaction of oxygen with the butadiene polymer in the absence of direct ultraviolet radiation. 
     
     
         25 . The composition of  claim 1 , wherein the butadiene polymer has a number average molecular weight (M n ) in the range of from about 500 to about 5,000. 
     
     
         26 . The composition of  claim 1 , wherein the butadiene polymer has a number average molecular weight (M n ) in the range of from about 1,000 to about 3,000. photoinitiator. 
     
     
         27 . The composition of  claim 1 , further comprising a UV or visible light 
     
     
         28 . The composition of  claim 27 , wherein the UV or visible light photoinitiator is selected from the group consisting of benzophenone, acetophenone, valerophenone, or titanocene. 
     
     
         29 . The composition of  claim 1 , wherein the titanium dioxide is doped with a doping agent selected from the group consisting of noble metal, a transition metal, and a non-metal. 
     
     
         30 . A packaging film structure, comprising:
 an oxygen scavenging layer comprising a blend of a base polymer, a butadiene polymer, and titanium dioxide in an amount sufficient to catalyze reaction of oxygen with the butadiene polymer.   
     
     
         31 . The packaging film structure of  claim 30 , further comprising one or both of an outer layer and a heat sealant layer. 
     
     
         32 . The packaging film structure of  claim 31 , wherein one or both of the outer layer and a heat sealant layer comprises the base polymer. 
     
     
         33 . The packaging film structure of  claim 30 , further comprising a barrier layer selected from a gas barrier layer and a moisture barrier layer.