We then sought to prepare a new class of SIPs containing the same structural units as MC2-MC4 to evaluate their depolymerization performance. Thus, three monomers, M2-M4 containing vinyloxycarbonyl (Vi) and benzyl thiol moieties were designed and synthesized (Scheme 1). Subsequently, photo-initiated thiolene click polymerization was conducted to generate polymers (Scheme 1). Taking the polymerization of M2 as an example, different solvents and monomer concentrations were screened. THF was a good solvent to afford Vi-P2a with a Mn of 9.7 kg/mol when the initial concentration of M2 was 1.0 M (Table ). A higher initial concentration of M2 (2.0 M) in THF led to formation of Vi-P2d with a slightly higher Mn of 10.3 kg/mol, which is characteristic of step-growth polymerization (Figures ). The thermal properties of Vi-P2d were assessed by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Vi-P2d had relatively high thermal stability with a decomposition temperature (Td, 5% weight loss) above 220 o C (Figure ) and a glass transition temperature (Tg) around 64 o C (Figure ). Thiol-ene polymerization of M3 in THF generated Vi-P3 with a Mn of 7.7 kg/mol (Figures ). Multiple attempts to obtain thiol-ene polymer from M4 failed as only insoluble product was obtained, for reasons that are not clear at this time. A one-pot synthesis of a block copolymer was also attempted via thiol-ene polymerization of M2 in the presence of allyl ether-terminated PEG (PEG-Allyl ether), successfully producing Vi-P2e-b-PEG as confirmed by both 1 H NMR and SEC characterization (Figures ). Scheme 2. Thiol-ene click end-functionalization toward various triggerable self-immolative polymers.