Pyrene functional poly(vinyl alcohol) by “click” chemistry

Abstract

Side-chain pyrene functional poly(vinyl alcohol) (PVA) was synthesized by using ''click chemistry'' strategy. First, partial tosylation of PVA with p-toluene sulfonyl chloride were performed. The resulting PVA-Ts polymer was then quantitatively converted into poly(vinyl alcohol)-azide (PVA-N 3 ) in the presence of NaN 3 /DMF at 60 C. Propargyl pyrene was prepared independently as a photoactive click component. Finally, azido functionalized PVA was coupled to propargyl pyrene with high efficiency by click chemistry. Incorporation of pyrene functionality in the resulting polymer was confirmed by spectral analysis. It is also shown that pyrene functionalized PVA (PVA-Py) exhibited characteristic fluorescence properties and improved solubility in highly polar solvents such as water, DMSO, and DMF as well as less polar solvent such as THF compared with pristine PVA. V

New copolymers with triazole pendant groups: Synthesis, characterization and their application to remove heavy metals

“…The 1 H NMR spectrum of PVA-N3 is in agreement with the results reported by Yacgi et al [7], where a signal at 4.02 ppm is due to -CHN 3 . …”

“…In the case of PVA-N3 it can be seen the characteristic signal of the azide group at 2094 cm -1 [7], which is very intense and shows the effective replacement of the tosyl groups. Regarding samples PVATPHM and PVATPGal the fingerprint area differs not only among themselves but also with respect to the precursor, in this case PVA-N3.…”

“…PVA (98+%, 89000-98000 g/mol, Aldrich Co), dimethyl formamide (DMF), ethanol (≥ 99.5%), diethylether (98%, Sigma-Aldrich), methanol (99%), dimethyl sulfoxide (DMSO, ≥ 99%), anhydrous with p-toluene sulfonyl chloride (p-TsCl; 1:1; in terms of hydroxyl moieties) in the presence of anhydrous pyridine at room temperature yielded PVA-Ts [7].…”

“…Degree of tosylation reaction was obtained from 1 H RMN spectrum. Areas from aromatic and methyne protons (signals between 7-8 ppm and 3.9 ppm, respectively) were analyzed to determinate these values [7].…”

“…This methodology is appropriate to obtain five members heterocyclic rings, particularly 1,2,3-triazole. Yacgi et al [7] used a convergent strategy to obtain chromophoric pendant groups incorporated to the modified PVA.…”