Polymerization process with catalyst reactivation

Abstract

Polymerization processes of the present invention comprise low catalyst concentration. Embodiments include a polymerization process comprising polymerizing free radically (co)polymerizable monomers in a polymerization medium comprising one or more radically (co)polymerizable monomers, a transition metal catalyst complex capable of participating in a one electron redox reaction with an ATRP initiator; a free radical initiator; and an ATRP initiator; (wherein the concentration of transition metal catalyst complex in the polymerization medium is less than 100 ppm). Further embodiments include a polymerization process, comprising polymerizing one or more radically (co)polymerizable monomers in the presence of at least one transition metal catalyst complex; an ATRP initiator; and a reducing agent; wherein the transition metal catalyst complex is present at less than 10 −3 mole compared to the moles of radically transferable atoms or groups present on the ATRP initiator.

1 . A polymerization process, comprising:
 polymerizing one or more radically (co)polymerizable monomers in the presence of:
 at least one transition metal catalyst complex; 
 an ATRP initiator; and 
 a reducing agent, 
 wherein the transition metal catalyst complex is present at less than 10 −3  mole compared to the moles of radically transferable atoms or groups present on the ATRP initiator. 
   
     
     
         2 . The polymerization process of  claim 1 , wherein the reducing agent comprises one or more compounds capable of reducing the transition metal catalyst by one oxidation state. 
     
     
         3 . The polymerization process of  claim 2 , wherein the polymerization process is one of a suspension polymerization process, an emulsion polymerization process, a miniemulsion polymerization process, or a microemulsion polymerization process. 
     
     
         4 . The polymerization process of  claim 2 , wherein the reducing agent is selected from the group consisting of includes SO 2 , sulfites, bisulfites, thiosulfites, mercaptans, hydroxylamines, amines, hydrazine (N 2 H 4 ), phenylhydrazine (PhNHNH 2 ), hydrazones, hydroquinone, food preservatives, flavonoids, beta carotene, vitamin A, α-tocopherols, vitamin E, propyl gallate, octyl gallate, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), propionic acids, ascorbic acid, sorbates, reducing sugars, sugars comprising an aldehyde group, glucose, lactose, fructose, dextrose, potassium tartrate, nitrites, nitrites, dextrin, aldehydes, glycine, and transition metal salts. 
     
     
         5 . The polymerization process of  claim 1 , wherein the polymerizing is conducted in a polymerization medium and the concentration of transition metal in the reaction is less than 100 ppm. 
     
     
         6 . The polymerization process of  claim 5 , wherein the concentration of transition metal in the reaction is less than 50 ppm. 
     
     
         7 . The polymerization process of  claim 5 , wherein the concentration of transition metal in the reaction is less than 10 ppm. 
     
     
         8 . The polymerization process of  claim 1 , wherein the transition metal catalyst complex is a (pseudo)halogen transfer agent. 
     
     
         9 . The polymerization process of  claim 1 , wherein the transition metal catalyst complex in an activator state is generated in situ from the reduction of the transition metal catalyst complex in the deactivator state by the reducing agent. 
     
     
         10 . The polymerization process of  claim 1 , wherein the transition metal catalyst complex comprises a transition metal and a ligand. 
     
     
         11 . The polymerization process of  claim 10 , wherein the ligand and transition metal form a transition metal catalyst complex wherein the higher oxidation state is an efficient deactivator. 
     
     
         12 . The polymerization process of  claim 10 , wherein conditional stability constant of the transition metal catalyst complex is greater than 10 6 . 
     
     
         13 . The polymerization process of  claim 10 , wherein the ligand on the transition metal catalyst complex and the reducing agent are selected to control the PDI of the formed polymer. 
     
     
         14 . The polymerization process of  claim 10 , wherein the ligand is selected to provide a stable complex in the presence of an acid. 
     
     
         15 . The polymerization process of  claim 1 , wherein the reducing agent is added continuously or periodically to the polymerization process. 
     
     
         16 . The polymerization process of  claim 1 , wherein the reduction of the transition metal catalyst complex in a deactivator state is to the transition metal catalyst complex in the activator state by the reducing agent does not result in formation of an acid. 
     
     
         17 . The polymerization process of  claim 1 , wherein the reducing agent and catalyst complex act to remove oxygen from the reaction medium or reaction environment. 
     
     
         18 . The polymerization process of  claim 17 , wherein the ligand is present from greater than a stoichiometric amount relative to the transition metal to 10 times a stoichiometric amount relative to the transition metal. 
     
     
         19 . The polymerization process of  claim 17 , wherein the ligand is present from greater than a stoichiometric amount relative to the transition metal to 3 times a stoichiometric amount relative to the transition metal.