Step-growth polymerization system: A-End B-B B-End Α A A3 A₁ B₂ B₁₁ Moles of molecules: NA3,0 NA1,0 NB2,0 = 1.5 NA3,0 NB1,0 = NA1,0 Moles of A/B groups: 3NA3,0 NA1,0 2NB2,0 = 3NA3,0 NB1,0 = NA1,0
Monofunctional small-molecule carbamates ( 1 urethane bond per molecule) are used to deconstruct crosslink polyurethane (form by a stoichiometric mixture of difunctional isocyanate and trifunctional alcohols) via urethane bond exchange reactions (see Scheme below). Based on the reverse of the lory-Stockmayer "gelation" theory discussed in class, determine the amount of small-molecule carbamate decrosslinkers required to deconstruct crosslinked polyurethane (i.e., determine the mol% of the urethane bonds in small-molecule carbamate decrosslinkersrelative to the total urethane bonds in small-molecule carbamate decrosslinkers+crosslinked polyurethane, at which crosslinked polyurethane deconstructs). Hint: Small-molecule carbamate decrosslinker can be treated as a mixture of monofunctional alcohols (example A1) and monofunctional isocyanates (example B1) at full
AI-generated content may present inaccurate or offensive content that does not represent bartleby’s views.
Unlock instant AI solutions
Tap the button
to generate a solution
