Li N, Wang H, Qu X, Chen Y. Synthesis of Poly(norbornene-methylamine), a Biomimetic of Chitosan, by Ring-Opening Metathesis Polymerization (ROMP).
Mar Drugs 2017;
15:E223. [PMID:
28708109 PMCID:
PMC5532665 DOI:
10.3390/md15070223]
[Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 07/05/2017] [Accepted: 07/09/2017] [Indexed: 11/16/2022] Open
Abstract
ROMP is an effective method for preparing functional polymers due to its having characteristics of "living" polymerization and rapid development of catalysts. In the present work, poly(norbornene-methylamine), a mimic of chitosan, was synthesized via ROMP reaction. The amino-protected product, 5-norbornene-2-(N-methyl)-phthalimide, was prepared by a reaction of 5-norbornene-2-methylamine with phthalic anhydride, which was then subjected to the ROMP reaction in the presence of Hoveyda-Grubbs 2nd catalyst to afford poly(norbornene-(N-methyl)-phthalimide). The target product, poly(norbornene-methylamine), was obtained by deprotection reaction of poly(norbornene-(N-methyl)-phthalimide). The products in each step were characterized by FTIR and ¹H-NMR, and their thermal stabilities were determined by TG analysis. The effects of molar ratio between monomer ([M]/[I]) and catalyst on the average relative molecular weight ( M n ¯ ) and molecular weight distribution of the produced polymer products were determined by gel permeation chromatography (GPC). It was found that the M n ¯ of poly(norbornene-(N-methyl)-phthalimide) was controllable and exhibited a narrow polydispersity index (PDI) (~1.10). The synthesis condition of 5-norbornene-2-(N-methyl)-phthalimide was optimized by determining the yields at different reaction temperatures and reaction times. The highest yield was obtained at a reaction temperature of 130 °C and a reaction time of 20 min. Our work provides a new strategy to synthesize polymers with controllable structures and free -NH₂ groups via ROMP.
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