Methyl 5 norbornene 2 3 dicarboxylic anhydride

Succinic anhydride (98%), 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride (EDC.HCl, 99%), glutaric anhydride (98%), 4-(aminomethyl)benzonitrile hydrochloride (98%), CS (Mw = 80 kDa, 70% deacetylation degree), formamidine acetate (98%), and zinc (II) trifluoromethanesulfonate (99%) were purchased from Tokyo Chemical Industry. Bis(2-hydroxylethyl) disulfide (90%, Alfa Aesar). Sodium nitrite (97%), PEG 4000, methyl-5-norbornene-2,3-dicarboxylic anhydride (99%) triethylamine (TEA, 99%), 4-(dimethylamino)pyridine (DMAP, 99%), 1,4-dithiothreitol (DTT, 98%), N-hydroxysuccinimide (NHS, 98%), and silica gel powder (230–400 mesh) were bought from Sigma Aldrich. DMSO, hexane, acetonitrile, dichloromethane (DCM), ethyl acetate, and diethyl ether were obtained from SK Chemicals. Polyethylene glycol carboxylic acid (PEG-COOH) was prepared by the method in our previous paper [33 (link)].

Tetraethyl orthosilicate (TEOS, >99%), (3-aminopropyl)-triethoxysilane (APTES, >98%) and ethanol (ACS reagent, anhydrous) were purchased from Sigma-Aldrich (St. Louis, MO, USA). A commercial epoxy monomer (component A of the resin system SX10) supplied by MATES S.r.l. (Milan, Italy), consisting of a modified bisphenol A diglycidyl ether and a bio-derived furanic diglycidyl ether, namely 2,5-bis[(oxyran-2-ylmethoxy)methyl]furan (BOMF, synthesized on purpose [22 (link)]), were used as epoxy monomers. As curing agent for both the epoxy monomers, methyl-5-norbornene-2,3-dicarboxylic anhydride (methyl nadic anhydride, MNA, 90%) purchased from Sigma-Aldrich (St. Louis, MO, USA) was employed. 2-Methylimidazole (2-MI, 99%), purchased from Acros Organics (Fisher Scientific, Hampton, NH, USA), was used as initiator for the curing process.