We report a green solvent-to-polymer upgrading transformation of chemicals of the lactic acid portfolio into water-soluble lower critical solution temperature (LCST)-type acrylic polymers. Aqueous Cu(0)-mediated living radical polymerization (SET-LRP) was utilized for the rapid synthesis of N -substituted lactamide-type homo and random acrylic copolymers under mild conditions. A particularly unique aspect of this work is that the water-soluble monomers and the SET-LRP initiator used to produce the corresponding polymers were synthesized from biorenewable and non-toxic solvents, namely natural ethyl lactate and BASF's Agnique® AMD 3L ( N , N -dimethyl lactamide, DML). The pre-disproportionation of Cu( i )Br in the presence of tris[2-(dimethylamino)ethyl]amine (Me 6 TREN) in water generated nascent Cu(0) and Cu( ii ) complexes that facilitated the fast polymerization of N -tetrahydrofurfuryl lactamide and N , N -dimethyl lactamide acrylate monomers (THFLA and DMLA, respectively) up to near-quantitative conversion with excellent control over molecular weight (5000 < M n < 83 000) and dispersity (1.05 < Đ < 1.16). Interestingly, poly(THFLA) showed a degree of polymerization and concentration dependent LCST behavior, which can be fine-tuned ( T cp = 12–62 °C) through random copolymerization with the more hydrophilic DMLA monomer. Finally, covalent cross-linking of these polymers resulted in a new family of thermo-responsive hydrogels with excellent biocompatibility and tunable swelling and LCST transition. These illustrate the versatility of these neoteric green polymers in the preparation of smart and biocompatible soft materials.
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Synthesis, electropolymerization and functionalization via click chemistry of N -alkynylated dithieno[3,2- b :2′,3′- d ]pyrrole
A new N-alkynylated dithieno[3,2- b :2′,3′- d ]pyrrole (DTP) monomer was synthesized using a Buchwald–Hartwig amination of 3,3′-dibromo-2,2′-bithiophene with pent-4-yn-1-amine. The obtained monomer was investigated for the possibility of a pre-polymerization modification via Huisgen 1,3-dipolar cycloaddition (“click”) reaction with azide-containing organic compounds. The synthesized N-alkynylated DTP monomer is soluble in a number of organic solvents and reacts with organic azides via “click” reactions in mild conditions, achieving high yields. The N-alkynylated DTP monomer and its “click”-modified derivative can be electropolymerized to form polymeric films. Herein, the synthesis and characterization of a “click” modified DTP monomer, its pre-modified derivative, and their corresponding polymers are described. The developed method is a facile route to synthesize a new generation of various N-functionalized DTP homopolymers.
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- Award ID(s):
- 1632881
- NSF-PAR ID:
- 10377329
- Date Published:
- Journal Name:
- RSC Advances
- Volume:
- 12
- Issue:
- 45
- ISSN:
- 2046-2069
- Page Range / eLocation ID:
- 29187 to 29196
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1039/d2ra03265a
