Pyridine

Lignocellulose (Pinus densiflora S. et Z.) with a lignin content of 31.4% was used as the raw material for lignin isolation. ChCl, LA, pyridine, dimethylformamide (DMF), tetrahydrofuran (THF), and 1M hydrochloric acid solution were purchased from Daejung Chemical & Metals (Siheung, Korea). Palmitoyl chloride (PC) was purchased from Tokyo Chemical Industry (Tokyo, Japan). PLA (IngeoTM Biopolymers 6400D) was obtained from NatureWorks LLC (Minnetonka, MN, USA).

Poly(acrylic acid) (PAA, M_w: 100,000 g mol⁻¹, 35 wt% in H₂O), 2-amino-4-hydroxy-6-methylpyridine, tert-butyl acrylate (tBA) and poly(ethylene glycol) methyl ether methacrylate (PEG-MEMA) were obtained from Sigma-Aldrich. Hexamethylene diisocyanate, 2-hydroxyethyl acrylate (HEA) and dibutyltindilaurate (DBTDL) were purchased from TCI. Azobisisobutyronitrile (AIBN), hexane, chloroform, dimethylformamide, acetone, pyridine and trifluoroacetic acid (TFA) were received from Daejung. Silicon powder (crystalline, APS ≤ 50 nm) was purchased from Alfa-Aesar. The electrolyte (1 M LiPF₆ in a combination of ethylene carbonate (EC) and ethyl methyl carbonate (EMC) (EC:EMC = 1:2 v/v) with 10% fluoroethylene carbonate (FEC) was purchased from Panax Etec. 2-(((6-(3-(6-methyl-4-oxo-1,4-dihydropyrimidin-2-yl)ureido)hexyl)carbamoyl)oxy)ethyl acrylate (UPy-containing monomer, UPyA) was prepared following the literature procedure^{61 (link)}. For polymerization, each monomer was subjected to an inhibitor removal process, and HPLC grade solvent was used.

Dieckol (1, 98.5%) was isolated from Ecklonia cava collected off the coast of Jeju Island, South Korea and supplied by Botamedi Inc. (Jeju, Korea). Benzoyl chloride and p-toluoyl chloride were purchased from Sigma-Aldrich Co. (St. Louis, MO, USA). Acetyl chloride, pyridine, acetone, chloroform and methanol were purchased from Daejung Chemicals (Gyeonggi-do, Republic of Korea). Propionyl chloride was purchased from Alfa Aesar (Ward Hill, MA, USA). acetone was dehydrated with 4 Å molecular sieves before use. Analytical thin-layer chromatography (TLC) was performed using Merck Kieselgel 60 F₂₅₄ pre-coated plates (0.25 mm) with a fluorescent indicator and visualized under UV light (254 and 365 nm). Column chromatography was performed on silica gel 60, 70−230 mesh. Dulbecco’s Modified Eagle Medium (DMEM), fetal bovine serum (FBS), and penicillin–streptomycin were obtained from Gibco Co. (Carlsbad, CA, USA). Lastly, 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) was purchased from TCI Inc. (Tokyo, Japan).