Insoluble and branched polyphosphonates and methods related thereto
View Patent ↗Insoluble polyphosphonates produced via a transesterification process, methods for preparing such insoluble polyphosphonates and polymer compositions and articles of manufacture including such insoluble polyphosphonates are described herein.
1. A method for producing branched insoluble polyphosphonates comprising:
combining one or more phosphonic acid diaryl esters and one or more bisphenol in a reaction vessel to form a reaction mixture;
adding an alkali catalyst to the reaction mixture;
heating the reaction mixture for a first time under vacuum to a temperature where phenol begins to distill from the vessel and continuing heating until evolution of phenol has stopped; and
heating the reaction mixture for a second time to a temperature where evolution of at least phenol has restarted and has stopped and a resulting branched insoluble polyphosphonate been generated that is partially or completely insoluble in methylene chloride or tetrahydrofuran after 8 hours of immersion;
wherein heating is carried out for a total of about 12 hours to about 16 hours.
2. The method of claim 1 , wherein the step of heating the reaction mixture for a second time is carried out for a time that is at least equal to the step of heating the reaction mixture for a first time.
3. The method of claim 1 , wherein a melt viscosity of the reaction mixture increases by at least about 10 times during the step of heating the reaction mixture for a second time.
4. The method of claim 1 , wherein the step of heating the reaction mixture for a first time and heating the reaction mixture for a second time are carried out concurrently such that heating is uninterrupted.
5. The method of claim 1 , wherein the reaction mixture comprises up to about 20 mole % molar excess of the bisphenol or up to about 20 mole % molar excess of the phosphonic acid diaryl ester.
6. The method of claim 1 , wherein the catalyst is sodium associated with an anion.
7. The method of claim 1 , wherein the alkali catalyst is sodium phenolate.
8. The method of claim 1 , further comprising adding a branching agent to the reaction mixture.
9. The method of claim 8 , wherein the branching agent is 1,1,1-tris(4-hydroxyphenyl)ethane.
10. The method of claim 1 , wherein the phosphonic acid diaryl ester is of general structure:
wherein R is a lower alkyl aliphatic hydrocarbon, a C 1 -C 4 , cycloaliphatic or aromatic.
11. The method of claim 1 , wherein the bisphenol is selected from 4,4′-dihydroxybiphenyl, 2,2-bis(4-hydroxyphenyl)propane (bisphenol A), 1,1-bis(4-hydroxyphenyl)-3,3-dimethyl-5-methyl cyclohexane (TMC), 1,3-dihydroxybenzene (resorcinol), 1,4-dihydroxybenzene (hydroquinone) and combinations thereof.
12. The method of claim 1 , wherein the molar amount of catalyst is from 0.00004 to about 0.001 moles per 1 mole of bisphenol.