Graft Polymerization of Acrylic Monomers onto Lignin with CaCl₂–H₂O₂ as Initiator: Preparation, Mechanism, Characterization, and Application in Poly(lactic acid)

Abstract

Effective utilization of abundant industrial lignin has growingly attracted much attention besides potential environmental issues. Although chemical graft polymerization modification is one facile strategy for extending its applications, it remains an intractable challenge to select a highly efficient initiation system. We herein have attempt to understand the CaCl 2 − H 2 O 2 system in initiating the graft polymerization of acrylic monomers onto acetic acid lignin (AAL) and biobutanol lignin (BBL). The initiation system is found to be highly efficient and selective, as proved by the successful graft of polyacrylates onto them, and a possible mechanism is also proposed. Thermal analysis shows that the graft modification results in a higher glass transition temperature and higher thermal stability of lignin. The graft modification make both AAL and BBL become more hydrophobic than before modification. Moreover, adding a small amount of lignin-graf t-polyacrylate can considerably improve the UV blocking capability in addition to the reinforcing effect on polylactic acid. This work offers a novel, highly effective, and selective free radical initiation system for functionalizing lignin.

Lignin Biopolymers in the Age of Controlled Polymerization

“…The use of free radical graft polymerization on lignin novel materials has been carried out in various applications, such as in composites [63], cationic flocculants [64,65], binder in lithium-ion batteries [66], heavy metal ion biosorption [67], anticancer [68], UV-absorbent films [69], and corrosion inhibition [70].…”

Natural Polymers from Biomass Resources as Feedstocks for Thermoplastic Materials

“…However, strong intermolecular interactions were detected using differential scanning calorimetry (DSC) and FT‐IR spectroscopy, concluding that hydrogen bonds between the phenolic hydroxyl groups of lignin and the carbonyl groups of PLA were formed . The compatibility of such blends could be enhanced via reactive grafting of either PLA copolymers or acrylic monomers onto lignin.…”

Facile preparation of uniform polydopamine particles and its application as an environmentally friendly flame retardant for biodegradable polylactic acid

“…1 Out of the myriads of bio-based polymers, polylactic acid (PLA) is strategically important due to its excellent mechanical properties, biocompatibility, renewability, biodegradability, easy dyeability, and above all, low cost. [2][3][4] Interestingly, PLA is now applicable in areas such as cable insulators, furnishings, high-end fashion items, building and construction, automobiles, and packaging. [5][6][7] Despite the enormous potentials of PLA, notable setbacks such as low thermal resistance, heat distortion temperature and high flammability accompanied by severe melt dripping limits its applications in certain fields.…”