These were assigned to the bridging methylene (I-CH2-I) and methylene group and hydrogen bonded terminal methylol
functions (I-CH2-OH), respectively.
During formation of b-stage resin, a dominant reaction occurs between two equivalents of the thus formed methylol
phenol with itself to form a longer-chain methylol
phenolic that has an ortho-ortho substituted methine bridge.
This could be explained by additional condensation reaction (postcure phenomenon) involving either residual methylol
groups or phenolic hydroxyl groups (3,391 [cm.sup.-1]) [28, 29].
Chaikumpollert, A method for preservation of natural rubber latex using methylol
compounds, National Science and Technology Development Agency, 2010, Malaysia patent MY142541 (A).
Zigon, "Aliphatic hyperbranched polyesters based on 2,2-bis(methylol
)propionic acid--Determination of structure, solution and bulk properties," Progress in Polymer Science, vol.
of hydroxymethyl resorcinol could react with the amino groups on HPAM.
It characterizing the course of reaction completeness of the methylol
ureas and metilol groups formation, characterizing stitching degree at polycondensation in the solution containing [Ca.sup.2+] and in control solution without [Ca.sup.2+].
2, 2-bis methylol
propanoic acid, dipentaerythritol, and silver benzoate were procured from Aldrich, Germany.
This peak was related with the condensation of phenolic and methylol
groups to form methylene bridges .
The interaction of formaldehyde with the functional groups of amino acids (e.g., primary amines and thiols) forms methylol
adducts that can further crosslink with other amino acids through methylene bridge formation (25).