Hofmann reaction of polyacrylamide: Relationship between reaction condition and degree of polymerization of polyvinylamine

“…The differences obtained from the ESCA angles show an increased conversion in the grafted layer when approaching the surface. Considering the partial hydrolysis of amide groups and urea formation which occur as bi-reactions in the Hofmann rearrangement [22,23] the increase in nitrogen indicates a substantial yield of amine groups.…”

Section: Coupling Reactionsmentioning

confidence: 99%

“…Since this reaction has been successfully applied in the conversion of polyacrylamide to polyvinylamine segments in high yields [22,23], we have used this method for the aminization of AAm grafted substrates. In our case the method was modified by making the reaction at room temperature to shorten the reaction time while maintaining a conversion of about 70 mole%.…”

Section: Functionalizationmentioning

confidence: 99%

Solvent free vapour phase photografting of acrylamide onto poly(methyl methacrylate)

Wirsén¹,

Sun²,

Albertsson³

2005

Polymer

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“…22,23 Among them, Hofmann degradation of polyacrylamide is one of the simplest methods; it uses a readily available monomer and can result in a high amine content. 24 The Hofmann degradation reaction mechanism is shown in Scheme 2. The modified polymer consisted of four monomeric units: acrylic acid, VAm, MMA, and AAm.…”

Section: Synthesis Of the Modified Poly(aam-co-mma-covam-co-aac) Hydrmentioning

confidence: 99%

Synthesis of poly(acrylamide-co-methyl methacrylate-co-vinyl amine-co-acrylic acid) hydrogels by Hoffman degradation and their interactions with acetaminophen

Begam¹,

Tomar²,

Nagpal³

et al. 2004

J. Appl. Polym. Sci.

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ABSTRACT:A modified poly(acrylamide-co-methyl methacrylate-co-vinyl amine-co-acrylic acid) [poly(AAm-co-MMA-co-VAm-co-AAc)] hydrogel was prepared by the Hofmann degradation of poly(acrylamide-co-methyl methacrylate) [poly(AAm-co-MMA)] copolymer. The hydrogel was characterized by Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis, and swelling studies. Matrices of this hydrogel with acetaminophen were prepared for application in controlled release. The physical state of the drug (acetaminophen) and its interaction with the modified polymeric hydrogel were examined in hydrogel-acetaminophen matrices with DSC. The acetaminophen in the matrices (with more than 10% drug) exhibited distinct melting endotherms because of their crystalline state. The peak temperature of these endotherms was lowered and the peaks were broadened as the concentration of acetaminophen decreased. The melting enthalpy of acetaminophen in various matrices when plotted as a function of acetaminophen concentration yielded a straight line with an intercept of 142 mg/g of matrix, which was the solubility of acetaminophen in the hydrogel at its melting temperature. FTIR spectroscopy investigations confirmed that hydrogen bonding occurred between the modified polymeric hydrogel and acetaminophen. Scanning electron microscopy studies revealed the presence of acetaminophen drug crystals of various shapes, sizes, and roughness on the surface, depending on acetaminophen loading. The controlled release of acetaminophen was tested in vitro; 67.10 and 37.2% cumulative releases were obtained for the poly(AAm-co-MMA) and poly(AAm-co-MMA-coVAm-co-AAc) hydrogel matrices, respectively. The acetaminophen release percentage for the modified hydrogel was low because of secondary interactions with acetaminophen.

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Hofmann reaction of polyacrylamide: Relationship between reaction condition and degree of polymerization of polyvinylamine

Cited by 35 publications

References 9 publications

A novel structure and photochromism of heteropolyoxometalates dispersed in polymer networks

A novel structure and photochromism of heteropolyoxometalates dispersed in polymer networks

Solvent free vapour phase photografting of acrylamide onto poly(methyl methacrylate)

Synthesis of poly(acrylamide-co-methyl methacrylate-co-vinyl amine-co-acrylic acid) hydrogels by Hoffman degradation and their interactions with acetaminophen

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