Examination of some melamine-formaldehyde adducts by 13C nuclear magnetic resonance

Dawbarn, Mary C; Ebdon, John R.; Hewitt, S.J.; Hunt, Jerry E.; Williams, I.E.; Westwood, A. R. C.

doi:10.1016/0032-3861(78)90312-9

Cited by 31 publications

(6 citation statements)

References 6 publications

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“…13 C‐NMR spectroscopy was widely used to characterize the chemical structures of different modified melamine formaldehyde resins,22–25 but only recent works such as those of Mercer and Pizzi26, 27 are devoted to the characterization of resin/cellulose mixtures. These authors focused their works on melamine formaldehyde/wood particleboard and melamine‐urea‐formaldehyde/wood particleboard.…”

Section: Discussionmentioning

confidence: 99%

Reactions between melamine formaldehyde resin and cellulose: Influence of pH

Devallencourt

Saiter

Capitaine

2000

J. Appl. Polym. Sci.

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Nuclear magnetic resonance of 13C in the liquid state and dynamic mechanical analysis were performed on composite materials obtained from a sample of ashless filter paper immersed in aqueous solutions of a melamine formaldehyde resin with a high NH ratio. The resin aqueous solution was studied at pH 6, 7, and 9. After a cure performed at 85°C we showed that acid conditions improved the mechanical properties of the composite because of self‐condensation reactions of the amino resin while for the other pH values the mechanical properties of the cellulose were not changed because mainly hydrolysis reactions occurred. For a cure performed at 140°C and under acid conditions the degree of crosslinking of the resin increased while for the other pH mainly cocondensation reactions appeared. Finally, from the study of moisture sorption measurements performed on a composite material elaborated at pH 7 and for different relative humidity values we showed that mainly the Langmuir absorption mode was modified by the presence of the resin. This last result allowed us to propose a complete scenario of the events that appeared during the formation of the composite material. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 1884–1896, 2000

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Section: Discussionmentioning

confidence: 99%

Reactions between melamine formaldehyde resin and cellulose: Influence of pH

Devallencourt

Saiter

Capitaine

2000

J. Appl. Polym. Sci.

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“…They were assigned by use of an HMBC 2D experiment 5 for 2 and 3 and by comparison with melamine derivatives for 5. 6 For the mono-and bismethanesulfonates, typical shifts are observed according to protonation effects: (i) for the carbons of the triazine (protonation at N-t3), (ii) for the protons H-p3/p5, H-m1 and the carbons C-p2/p6 in the piperazine series (protonation at N-p4) and (iii) for the protons H-p4 and H-e1 and for the carbons C-p3/p5 and C-e2 in the piperidine series (protonation at N-e0). The order determined for the successive protonations, N-t3, N-p4 in the piperazine series, N-e0, N-t3 in the piperidine series, is in good agreement with previous results obtained by 15 N NMR.…”

Section: Signal Assignmentsmentioning

confidence: 99%

Structural and conformational study of substituted triazines by1H and13C NMR analysis

et al. 2001

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“…Several analytical techniques have been used for analyzing MF resins 1, 2, 5, 10–22. For reactions carried out at 35, 40, and 70°C; and pH between 3 and 10.6, Okano and Ogata1 combined the results of the iodometric and sulfite methods5 for estimating the concentrations of F T and global methylols.…”

Section: Introductionmentioning

confidence: 99%

“…For reactions at pH > 8 and T > 70°C, several publications have analyzed the reaction products by 13 C‐NMR11–17 and 1 H‐NMR 14, 15, 18. Drawbarn et al,11 De Breet et al,12 and Tomita and Ono13 directly analyzed the oligomers mixture by 13 C‐NMR, employing dimethylsulfoxide (DMSO‐d 6 ) as solvent. In contrast, Ebdon et al14, 15 first isolated several reaction mixture components by preparative HPLC (with a water‐methanol mixture as mobile phase), and then analyzed each of the isolated components by NMR.…”

Section: Introductionmentioning

confidence: 99%

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Methylolation of melamine with incipient condensation. I. Synthesis and characterization

Nicolau

Martinelli

Strumia

et al. 2009

J of Applied Polymer Sci

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This work investigates five reactions between melamine (M) and formaldehyde (F) at pH ¼ 9.0, and with initial F : M ratios of 2. The samples were analyzed by size exclusion chromatography (SEC), volumetric techniques, and ( 1 H and 13 C) NMR. Condensation was quantified by the SEC measurements. In the experiments at 38 and 48 C, condensation was almost negligible, and the reversibility of methylolation reactions determined that equilibriums were reached in the ratios between primary, secondary, and tertiary amines. In the experiments at 60, 70, and 90 C, condensation was significant, but in all cases, the mass fraction of single-ringed species was larger than that of species with two or more rings per molecule. The following were estimated by combining the SEC and volumetric measurements: number-average molecular weights, and average functionalities of reactive H's, methylols, methylene bridges, and ether bridges. The dissolution of M in water was essentially instantaneous. The measurements are employed in the next article of this series for adjusting a novel mathematical model.

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Examination of some melamine-formaldehyde adducts by 13C nuclear magnetic resonance

Cited by 31 publications

References 6 publications

Reactions between melamine formaldehyde resin and cellulose: Influence of pH

Reactions between melamine formaldehyde resin and cellulose: Influence of pH

Structural and conformational study of substituted triazines by1H and13C NMR analysis

Methylolation of melamine with incipient condensation. I. Synthesis and characterization

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