End-group isomerization of poly(alkylene carbonate) polymers

Abstract

Described herein are methods of preparing poly(alkylene carbonate) polymers comprising an increased ratio of primary hydroxyl end groups to secondary hydroxyl end groups, and compositions thereof.

1 - 13 . (canceled) 
     
     
         14 . A poly(propylene carbonate) (“PPC”) polymer composition comprising a plurality of poly(propylene carbonate) polymer chains, where the poly(propylene carbonate) chains contain isopropylene moieties separating each carbonate linkage, characterized in that a percentage of intrapolymer adjacent isopropylene moieties are arranged in a head-to-tail enchainment, and a percentage of secondary OH end groups is less than a percentage of intrapolymer carbonate units arranged in a head-to-tail enchainment. 
     
     
         15 - 22 . (canceled) 
     
     
         23 . A method for increasing the ratio of primary to secondary OH end groups of a poly(propylene carbonate) (“PPC”) polymer composition, the method comprising the step of contacting a starting PPC polymer composition with an isomerization catalyst to provide a modified PPC polymer composition wherein the modified PPC polymer composition has a higher ratio of primary to secondary OH end groups than the starting PPC polymer composition. 
     
     
         24 . The method of  claim 23 , wherein the isomerization catalyst is a Lewis or Brönsted Acid, or a Lewis or Brönsted Base. 
     
     
         25 . (canceled) 
     
     
         26 . The method of  claim 24 , wherein the isomerization catalyst is a transition metal Lewis Acid, a main group Lewis acid, an alkali Lewis Acid, or an alkaline Lewis Acid. 
     
     
         27 . The method of  claim 26 , wherein the isomerization catalyst is a hydrogen halide, a hydrogen phosphate, an aluminum oxide, a boronic acid, a boronic ester, an alkyl borane, an aryl borane, an ammonium acid, a sulfonic acid, or a zeolite. 
     
     
         28 . The method of  claim 26 , wherein the isomerization catalyst is selected from zinc chloride, zinc bromide, zinc fluoride, zinc triflate, zinc oxide, aluminum chloride, aluminum bromide, aluminum fluoride, aluminum triflate, tin chloride, tin oxide, dibutyltin dilaurate, molybdenum dichloro dioxide, iron (II) chloride, iron (III) chloride, silica chloride, magnesium chloride, manganese chloride, cobalt (II) chloride, titanium chloride, copper bromide, copper triflate, lithium chloride, hydrogen chloride, hydrogen bromide, hydrogen iodide, hydrogen fluoride, boric acid, triphenylborane, trifluoroborane, tris(pentafluorophenyl)borane, fluoroantimonic acid, perchloric acid, trifluoromethanesulfonic acid, triflic anhydride, antimony pentafluoride, tetrabutylammonium bromide, tetrabutylphosphonium bromide, cesium triflate, chromium acetate, acetic acid, sulfuric acid, p-toluene sulfonic acid, methane sulfonic acid, ethane sulfonic acid, 1-propane sulfonic acid, trifluoromethyl sulfonic acid, 4-nitrophenyl sulfonic acid, sulfoacetic acid, cumenesulphonic acid, vylene sulfonic acid, 3-amino-1-1-propanesulfonic acid, 2-(methylamino)ethanesulfonic acid, 2-aminoethanesulfonic acid, 2-sulfanylethanesulfonic acid, 3-hydroxy-1-propanesulfonic acid, benzenesulfonic acid, 3-pyridinesulfonic acid, 2-pyridinesulfonic acid, 4-piperidinesulfonic acid, 2-aminobenzenesulfonic acid, 1-methylpyridinium 3-sulfonate, 1-methyl-2-pyridiniumsulfonate, 4-hydroxybenzenesulfonic acid, cyclohexane sulfonic acid, 4-ethylbenzenesulfonic acid, 2,5-dimethylbenzenesulfonic acid, 4-methylmetanilic acid, 4-amino-3-methylbenzenesulfonic acid, 1-Naphthalenesulfonic acid, 2-amino-5-methylbenzenesulfonic acid, perfluorooctane sulfonic acid, sulfamic acid, phosphoric acid, pyrophosphoric acid, triphosphoric acid, an alkyl derivative of phosphoric acid, pyrophosphoric acid, triphosphoric acid, an aryl derivative of phosphoric acid, pyrophosphoric acid, zinc glutarate, (beta-diiminate) zinc acetate, perfluorosulfonic acid polymer, or any combination thereof. 
     
     
         29 . The method of  claim 26 , wherein the isomerization catalyst is a boron-containing Lewis acid. 
     
     
         30 . The method of  claim 29 , wherein the isomerization catalyst is selected from the group consisting of: boric acid, a boronic ester, an alkyl borane, and an aryl borane 
     
     
         31 - 32 . (canceled) 
     
     
         33 . The method of  claim 24 , wherein the isomerization catalyst is an alkali carboxylate, an alkaline carboxylate, an alkyl amine, an aromatic amine, a phosphine, a phosphazene, an alkyl thiolate, an aryl thiolate, an alkali phosphate, an alkaline phosphate, a transition metal hydroxide, a transition metal oxide, an alkaline carbonate, an alkaline bicarbonate, an alkali carbonate, an alkali bicarbonate, or a phosphine oxide. 
     
     
         34 . The method of  claim 33 , wherein the isomerization catalyst is lithium acetate, calcium stearate, ammonia, 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), 1,5,7-triazabicylo[4.4.0]dec-5-ene (TBD), 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene (MTBD), 1,4-diazabicyclo[2.2.2]octane (DABCO), trimethylamine, lutidine, 4-dimethylaminopyridine, tetramethylethylenediamine, diisopropylamine, imidazole, 1-methylimidazole, 1-phenethylimidazole, 1-isopropylimidazole, pyridine, tributylphosphine, triphenylphosphine, triphenylphosphine oxide, bis(triphenylphosphine) iminium chloride, potassium thiophenolate, sodium thiophenolate, trisodium phosphate, tricalcium phosphate, aluminum hydroxide, tin oxide, calcium carbonate, lithium carbonate, potassium hydroxide, sodium hydroxide, diethyl zinc, trimethyl aluminum, dimethyl copper, potassium phosphate, potassium carbonate, sodium bicarbonate, MoOCl 2 , or any combination thereof. 
     
     
         35 . (canceled) 
     
     
         36 . The method of  claim 23 , wherein the isomerization catalyst is contacted with the starting PPC polymer for between about 1 minute to about 120 hours. 
     
     
         37 . The method of  claim 23 , wherein the isomerization catalyst comprises or is bound to a solid support,
 wherein the solid support comprises an inorganic solid support or a polymer solid support.   
     
     
         38 . (canceled) 
     
     
         39 . The method of  claim 37 , wherein the inorganic solid support is selected from silica, alumina, zirconia, titania, zeolites, metal oxides, and clays. 
     
     
         40 . The method of  claim 39 , wherein the polymeric solid support is styrene, chloromethylated styrene and divynylbenzene, polystyrenes, polysulfones, nylons, poly(chloromethylstyrene), polyolefins, polymethylmethacrylate, cross-linked ethoxylate acrylate resin polymers, or combinations of any of these. 
     
     
         41 . The method of  claim 37 , wherein the isomerization catalyst is Amberlyst-15, poly(4-vinylpyridine), montmorillite K-10, montmorillite KSF, zeolite, alumina, silica, a solid supported sulfonic acid, Naffion-H, HBF 4  on SiO 2 , or HClO 4  on SiO 2 . 
     
     
         42 . The method of  claim 23  wherein the starting PPC polymer composition is contacted with two different isomerization catalysts comprising boric acid, calcium stearate, or combinations thereof. 
     
     
         43 . (canceled) 
     
     
         44 . The method of  claim 23 , further comprising the step of heating the starting PPC polymer composition and isomerization catalyst. 
     
     
         45 . The method of  claim 23 , wherein the heating step comprises heating the starting PPC polymer composition and isomerization catalyst at a temperature in the range of about 50° C. to about 140° C. 
     
     
         46 - 47 . (canceled) 
     
     
         48 . The method of  claim 45 , wherein the isomerization catalyst is calcium stearate, and the starting PPC polymer and boric acid are heated to a temperature in the range of about 90° C. to about 120° C. 
     
     
         49 . (canceled) 
     
     
         50 . The method of  claim 23 , wherein an amount of cyclic propylene carbonate formed during the heating step is less than about 10 weight percent, about 9 weight percent, about 8 weight percent, about 7 weight percent, about 6 weight percent, about 5 weight percent, about 4 weight percent, about 3 weight percent, about 2 weight percent, or about 1 weight percent relative to the starting PPC polymer.