Ethylene oxide-containing copolymers and methods thereof

Abstract

The present invention is directed at a binder for a battery electrode comprising an ethylene oxide-containing copolymer including a first monomer of ethylene oxide (EO) and at least one additional monomer selected from an alkylene-oxide that is different from the first monomer of EO, an alkyl glycidyl ether, or a combination thereof; wherein the ethylene oxide-containing copolymer has a weight average molecular weight less than about 200,000 g/mole (e.g., from about 10,000 to about 100,000), the molar fraction of the first monomer of EO (X EO ) in the ethylene oxide-containing copolymer is greater than 0.80 (e.g., from about 0.80 to about 0.995), and the ethylene oxide-containing copolymer has a peak melting temperature (T p ), in ° C., for a selected X EO in the range of about 0.80 to about 0.995, which is below a maximum value of T pmax , at the selected X EO , which is calculated using the equation T pmax =(60−150 (1−X EO )).

1 . A process for polymerizing an ethylene oxide-containing copolymer, comprising contacting a first monomer of ethylene oxide and at least one additional monomer with a catalyst in the presence of a hydrocarbon diluent; at a reaction temperature less than the peak melting temperature of the copolymer for reacting the monomers to polymerize the copolymer;
 wherein the at least one additional monomer is an alkylene-oxide that is different from the first monomer of ethylene oxide, an alkyl glycidyl ether, an allyl glycidyl ether, or a combination thereof.   
     
     
         2 . The process of  claim 1 , wherein the catalyst is an alkyl aluminium catalyst; and the process further comprises a step of activating the alkylaluminum catalyst by contacting it with a Lewis base initiator to form the activated alkylaluminum catalyst. 
     
     
         3 . The process of  claim 2 , wherein the process further comprises a step of quenching the catalyst by adding a compound bearing an active proton. 
     
     
         4 . The process of  claim 2 , wherein the reaction temperature is from about 10° C. to about 45° C. 
     
     
         5 . The process of  claim 1 , wherein the catalyst includes an alkylaluminum catalyst selected from the group consisting of triisobutylaluminum, triethylaluminum, tri-n-hexylaluminum, or any combination thereof. 
     
     
         6 . The process of  claim 1 , wherein
 the ethylene oxide-containing copolymer has a weight average molecular weight less than about 200,000 g/mole,   the ethylene oxide-containing copolymer is a random copolymer having a polydispersity index, M w /M n , less than about 3,   the ethylene oxide-containing copolymer has a molar fraction of the first monomer of ethylene oxide, X EO , from about 0.80 to about 0.995, and   the ethylene oxide-containing copolymer has a peak melting temperature, T p , in units of ° C., for a selected X EO  in the range of about 0.80 to about 0.995, which is below a maximum value of T pmax , at the selected X EO , which is calculated using the equation T pmax =(60−150 (1−X EO )).   
     
     
         7 . The process of  claim 1 , wherein the at least one additional monomer includes propylene oxide. 
     
     
         8 . The process of  claim 1 , wherein the resulting ethylene oxide-containing copolymer has a polydispersity index of about 1.3 or less. 
     
     
         9 . The process of  claim 1 , wherein the resulting ethylene oxide-containing copolymer has a weight average molecular weight of about 200,000 or less. 
     
     
         10 . The process of  claim 7 , wherein the molar fraction of ethylene oxide is about 0.96 or less, based on the total moles of monomer in the copolymer. 
     
     
         11 . The process of  claim 10 , wherein the wherein the catalyst includes an alkylaluminum catalyst selected from the group consisting of triisobutylaluminum, triethylaluminum, tri-n-hexylaluminum, or any combination thereof. 
     
     
         12 . The process of  claim 11 , wherein the ethylene oxide-containing copolymer achieves a molecular weight polymer of 200,000 or less without the employment of an irradiation step or other chain scission step for reducing the molecular weight of the polymer. 
     
     
         13 . The process of  claim 12 , wherein a metal oxide or other anti-fouling agent is employed in the polymerization of the ethylene oxide-containing copolymer. 
     
     
         14 . The process of  claim 13 , wherein the trialkylaluminum catalyst is present at a molar ratio of about 1 to 30 mmol per mole of ethylene oxide. 
     
     
         15 . The process of  claim 14 , wherein the trialkylaluminum catalyst is present at a molar ratio from about 3 to about 8 mmol per mole of ethylene oxide. 
     
     
         16 . The process of  claim 15 , wherein the process includes a step of feeding the ethylene oxide at a molar rate F EO  and feeding the additional monomer at a molar rate F AO , wherein the ratio of F AO /F EO  is from about 0.010 to about 0.150. 
     
     
         17 . The process of  claim 16 , wherein the ratio of F AO /F EO  is from about 0.020 to about 0.080. 
     
     
         18 . The process of  claim 17 , wherein a Lewis base is employed for activating the catalyst, wherein the Lewis base is an amine having 4 to 20 carbon atoms, and the ratio of the Lewis base to the aluminum in the catalyst is greater than 0.05. 
     
     
         19 . The process of  claim 18 , wherein the process includes a step of terminating the polymerization reaction with an alcohol. 
     
     
         20 . A process for polymerizing an ethylene oxide-containing copolymer having a peak melting temperature of about 46° C. or less, comprising contacting a first monomer of ethylene oxide and at least one additional monomer with a catalyst in the presence of a hydrocarbon diluent; at a reaction temperature less than the peak melting temperature of the copolymer for reacting the monomers to polymerize the copolymer;
 wherein the at least one additional monomer includes propylene oxide, 
 the mole fraction of ethylene oxide in the copolymer is 0.90 or more and the mole fraction of the propylene oxide is 0.005 or more, based on the total moles of monomer in the copolymer.