Table 4. Recycling PUs through Depolymerization and Polycondensation^a.

	depolymerization of PU into monomers					repolymerized PU
entry	4	R	Mw/Mnb,f	Mwb	yield (%)c	4′	Mwd,f	Mw/Mnd,f	yield (%)e
1	4a	2a	1.21	28,000	85	4′a	18,100	1.34	51
2	4b	2b	1.24	28,000	73	4′b	10,800	1.30	31
3	4c	2c	1.24	22,000	89	4′c	13,000	1.35	65
4	4d	2d	1.38	14,000	91	4′d	8900	1.42	56
5	4e	2e	1.33	20,000	81	4′e	10,000	1.33	41

^aDepolymerization conditions as described in Table 2. Polymerization: the same process as described in Table 3 (with extra 0.1 equiv of monomer 2).

^bPU synthesized by diisocyanate approach.

^cIsolated yield (monomer 2, by column chromatography) of depolymerization, calculated for the urethane group.

^dPU synthesized by transcarbamoylation.

^eYield of polymerization.

^fDetermined by SEC.