Modified cyclohexanone–formaldehyde and acetophenone–formaldehyde resins

Abstract

SYNOPSISPreparation of in situ-modified cyclohexanone-formaldehyde and acetophenoneformaldehyde resins with compounds such as diphenols, melamine, andp-toluene sulfonamide were studied.Modification of acetophenoneformaldehyde resins with hydroxylamine, semicarbazide, phenylhydrazine, phthalic anhydride, and acetic anhydride was also studied. Melting points, solubilities in organic solvents, and FI?R and NMEt spectra of modified resins were determined. I NTRO D UCTlO NModification of cyclohexanone-formaldehyde resin via its hydroxyl and carbonyl groups has been previously studied.' Hydroxyl groups were reacted with acetyl chloride, benzoyl chloride, phthalic anhydride, and carbonyl groups with hydroxylamine, semicarbazide, and phenylhydrazine.In situ modification of acetophenone resin has been studied previously. The modifier compounds were phenol, p -cumylphenol, and p -cres01.~ The resulting resins were used for adhesives and binders.Modified cyclohexanone / formaldehyde resins were also prepared using MEK, MIBK, methylcyclohexanone, acetaldehyde, propionaldehyde, and cinnamaldehyde. These resins were used as binders for self-hardening molds.5In this work, cyclohexanone-formaldehyde and acetophenone-formaldehyde resins were modified during the preparation by the addition of a modifier compound/ formaldehyde mixture to the polymerization media. Compounds that react with formaldehyde in basic media were used as modifier compounds. These were melamine, resorcinol, p -toluene sulfonamide, bisphenol-A, and bisphenol-C.Modification of the acetophenone-formaldehyde resin via hydroxyl and carbonyl groups and reaction

Chain extended cyclohexanone-formaldehyde and acetophenone-formaldehyde resins

“…Preparation of the CF resin (10) and the AF resin (20) was carried out as described previously. 2 The resins were dried at 110°C under a vacuum. The CF and AF resins were further dried by refluxing with xylene using a Dean-Stark apparatus.…”

“…Cyclohexanone-formaldehyde (CF, 10) and acetophenone-formaldehyde (AF, 20) resins (Scheme 1) were modified via their hydroxyl and carbonyl groups in earlier studies. [1][2][3] The type of modifying compound had a marked affect on the melting point and solubilities of the modified resins. The molecular weights of the ketonic resins were not increased considerably by the modification reactions.…”

“…A variety of modified ketonic resins were produced by changing the ratio of the hydroxyl groups of the resin to the modifying reagent. [1][2][3] For example, when the molar ratio of hydroxyl to anhydride was about 1, all the hydroxyl groups of the ketonic resin reacted with phthalic anhydride to give a modified ketonic resin containing free carboxylic acid groups in place of the hydroxyl groups. If this ratio was 9 : 1, a dimeric chain extended CF resin was produced 3 because each CF-resin molecule contained approximately nine hydroxyl groups.…”

Ketonic resins as free radical photoinitiators

“…7,8 The reaction probably occurred via cross aldol condensation of formaldehyde with cyclohexanone and benzoin to give cyclohexanone methylol and benzoin methylol, which condensed to give CF-B or CF-BIBE (Scheme 1). The similar reactions between acetophenone, formaldehyde, and benzoin may also occur to give AF-B and AF-BIBE.…”

Novel unsaturated polyester resins based on (maleated cyclohexanone-formaldehyde resin)-(epoxy resin) condensation

“…This is usually used as coating additive [6][7][8], free radical photoinitiators [9], as a blend for the improvement of coating properties [10][11][12] and as an adhesive in multilayered laminated sheets [13]. A wealth information on modifying the CHF resins for its applications in various areas is available [14][15][16][17][18][19][20][21][22][23]. However the use of these modified CHF resins in certain specific fields has not been extensively covered.…”