# US 11,999,812 B2 · Recyclable crosslinked polymer networks containing dynamic dialkyl amino disulfide linkages > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,999,812 B2 - Document ID: US11999812B2 - Status: Granted - Kind: B2 - Application number: 17/380,259 - Filed: 2021-07-20 - Published: 2022-01-27 - Granted: 2024-06-04 - Earliest claimed: 2020-07-21 - Assignees: Northwestern University - Applicants: Northwestern University - Inventors: John M. Torkelson; Mohammed Abdulaziz Bin Rusayyis - Web page: https://patentgrep.com/patent/US11999812B2 ## CPC - C08F 220/1806: {C6-(meth)acrylate, e.g. (cyclo)hexyl (meth)acrylate or phenyl (meth)acrylate} - C08F 293/005: {using free radical "living" or "controlled" polymerisation, e.g. using a complexing agent} - C08F 120/14: Methyl esters {, e.g. methyl (meth)acrylate} - C08F 2438/00: Living radical polymerisation - C08F 2810/10: including a reactive processing step which leads, inter alia, to morphological and/or rheological modifications, e.g. visbreaking - C08F 2810/20: leading to a crosslinking, either explicitly or inherently - C08F: MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS ## Abstract A composition for forming a dynamic crosslinked polymer network may comprise (a) a dynamic crosslinker having formula R—R″R′N—S—S—NR′R″—R, wherein each R is a polymerizable group comprising a carbon-carbon (C—C) double bond capable of undergoing free radical polymerization and each R′ and each R″ are independently selected alkyl groups; (b) a polymer comprising a C—C double bond capable of undergoing free radical polymerization, a monomer comprising a C—C double bond capable of undergoing free radical polymerization, or combinations thereof; and (c) a free radical initiator, wherein the dynamic crosslinker does not comprise a urethane group. ## Claims ### Claim 1 A composition for forming a dynamic crosslinked polymer network, the composition comprising a dynamic crosslinker having formula R—R″R′N—S—S—NR′R″—R, wherein each R is a polymerizable group comprising a carbon-carbon (C—C) double bond capable of undergoing free radical polymerization, wherein each R′ and each R″ is an alkyl group, and further wherein one of R′ and R″ on each respective nitrogen is substituted with a respective R as a substituent thereon, wherein R′ and R″ are not covalently bound together and do not form a cycloalkyl group containing a respective nitrogen; a polymer comprising a C—C double bond capable of undergoing free radical polymerization, a monomer comprising a C—C double bond capable of undergoing free radical polymerization, or combinations thereof; and a free radical initiator, wherein the dynamic crosslinker does not comprise a urethane group. ### Claim 2 (depends on 1) The composition of claim 1, wherein the composition comprises the monomer. ### Claim 3 (depends on 2) The composition of claim 2, wherein the monomer has formula R1R2C═CR3R4, wherein each of R1-R4 is independently selected from hydrogen, halogen, alkyl, aryl, arylalkyl, alkenyl, arylalkenyl, alkoxycarbonyl, and alkylaminecarbonyl. ### Claim 4 (depends on 2) The composition of claim 2, wherein the monomer is a vinyl monomer. ### Claim 5 (depends on 2) The composition of claim 2, wherein the monomer is an acrylate monomer. ### Claim 6 (depends on 1) The composition of claim 1, wherein each R is —OCOCHCH2 or —OCOC(CH3)CH2, wherein “—” represents a covalent bond to one of R′ and R″ on each respective nitrogen. ### Claim 7 (depends on 1) The composition of claim 1, wherein each R″ and each R′ is a linear alkyl group or a branched alkyl group. ### Claim 8 (depends on 7) The composition of claim 7, wherein each R″ and each R′ has from 1 to 6 carbons. ### Claim 9 (depends on 8) The composition of claim 8, wherein each R is —OCOCHCH2 or —OCOC(CH3)CH2, wherein “—” represents a covalent bond to one of R′ and R″ on each respective nitrogen. ### Claim 10 A dynamic crosslinked polymer network comprising polymer chains covalently linked by dialkylamino disulfide linkages formed from a dynamic crosslinker having formula R—R″R′N—S—S—NR′R″—R, wherein each R is a polymerizable group comprising a carbon-carbon (C—C) double bond capable of undergoing free radical polymerization, wherein each R′ and each R″ is an alkyl group, and further wherein one of R′ and R″ on each respective nitrogen is substituted with a respective R as a substituent thereon, wherein R′ and R″ are not covalently bound together and do not form a cycloalkyl group containing a respective nitrogen, wherein the dynamic crosslinker does not comprise a urethane group. ### Claim 11 (depends on 10) The network of claim 10, wherein the polymer chains are derived from monomers having formula R1R2C═CR3R4, wherein each of R1-R4 is independently selected from hydrogen, halogen, alkyl, aryl, arylalkyl, alkenyl, arylalkenyl, alkoxycarbonyl, and alkylaminecarbonyl. ### Claim 12 (depends on 10) The network of claim 10, wherein the polymer chains are polyacrylates. ### Claim 13 (depends on 1) A method of forming a dynamic crosslinked polymer network, the method comprising generating free radicals from the free radical initiator in the composition of claim 1, to induce reactions of the dynamic crosslinker with C—C double bonds of the polymer, the monomer, or both, to form a dynamic crosslinked polymer network. ### Claim 14 (depends on 10) A method of reprocessing the network of claim 10, the method comprising heating the network to a first temperature that induces reversible dialkylamino disulfide bond cleavage; reshaping the network; and cooling the network to a second temperature at which the reversible dialkylamino disulfide bond cleavage is arrested. ### Claim 15 (depends on 14) The method of claim 14, wherein the heating, reshaping, and cooling step provides a first reprocessed network and the heating, reshaping, and cooling step is repeated at least 2 additional times to provide an additional reprocessed network exhibiting full recovery of crosslinking density.