1 1 methylenedi 4 1 phenylene bismaleimide

2,2-Bis(4-glycidyloxyphenyl)-propane (21.1 g, from Sigma-Aldrich) and furfurylamine (6.0 g, from TCI) were dissolved in N’N-dimethylformamide (DMF, 66.0 g) and reacted at 120 °C for 12 h to yield the furan contained linear polymer solution (M_n = 10,700 by gel permeation chromatography). Another 24.0 g DMF was added into the solution, and then 1,1’-(methylenedi-4,1-phenylene)bismaleimide (2.3 g, from Sigma-Aldrich) was fully dissolved in the linear polymer solution. Then, 5 mL of the obtained solution was poured into an aluminum dish (90 mm in diameter), and the dish was placed in a 70 °C oven for 5 h to evaporate the solvent. It was further dried in a vacuum oven (70 °C, 48 h) to yield a polymer film with thickness of 0.14 mm upon demolding. The samples were cut into the desired dimensions for various testing. Specifically, polymer films in dogbone shapes (neck dimension of 4 mm × 20 mm) were used in Fig. 1d (specimen 1 and 2) and Supplementary Figure 7. Rectangular specimens (4 mm × 40 mm) were used for Figs. 2d and 3a.

Furfuryl alcohol (FA; 98%), poly(ethylene glycol) methyl ether methacrylate(PEGMMA; average Mn = 500, contains 100 ppm MEHQ and 200 ppm BHT as inhibitor), dibutyltin dilaurate (95%), 1,1′-(methylenedi-4,1-phenylene)bismaleimide (bM; 95%) and 2-hydroxyethyl methacrylate(HEMA; contains 250 ppm monomethyl ether hydroquinone as inhibitor, 97%) were purchased from Sigma-Aldrich and used as received. 2-Furoyl chloride (FC; 98%) and 2-isocyanato ethyl methacrylate (NCO-MA, stabilized with BHT; 98%) were purchased from Tokyo Chemical Industry and used as received. α,α′-Azobis(isobutyronitrile) (AIBN; 98%) was purchased from Tokyo Chemical Industry and recrystallized with ethanol before used. Methylene chloride (MC), N,N-dimethylformamide (DMF), tetrahydrofuran (THF), n-hexane, chloroform, diethyl ether and pyridine (99.5%) were purchased from Daejung Chemicals and used after dehydration with molecular sieves.

Jatropha curcas oil (JO) was purchased from Dilligent BV, Eersel, Netherlands. Sunflower oil was purchased from Jumbo supermarket. Hydrogen peroxide solution (30%), formic acid (≥98%), sodium chloride (≥99%), furfurylamine (≥99%), 1,12-diaminododecane (98%), tris(2-aminoethyl)amine (96%), maleic anhydride (99%), triethylamine (≥99.5%), acetic anhydride (≥99%), DMF anhydrous (99.8%), silica gel 60 A 230-400#, silica gel technical grade 40 6-12#, 1,1′-(methylenedi-4,1-phenylene)bismaleimide (95%), and 2,5-dimethylfuran 99% were obtained from Sigma Aldrich (Munich, Germany). Peroxide test strips (0.5, 2, 5, 10, 25 mg/L H₂O₂) were procured from Merck (Darmstadt, Germany). Toluene (99.5%) and dichloromethane (99.5%) were purchased from Macron Fine Chemicals (Deventer, The Netherlands), whereas sodium chloride (≥99%) and lithium bromide (≥98%) were obtained from Fluka (Landsmeer, The Netherlands). A representative all-purpose mounting glue was purchased from Bison (Rotterdam, Netherlands), while aluminum sheets (20 × 20 × 0.01 cm³) were purchased from aluminiumfolie.nl (Gorinchem, The Netherlands).