Amide-blocked aldehyde monomers

Honomer Selection. In practice the amide/blocked aldehyde precursor 1 (ADDA) proved more readily accessible than 2. The two forms were completely Interconvertible and equally useful as self-and substrate reactive crosslinkers (6). In our addition polymer systems, the acrylamide derivative 1 (R=CH3) provided a good blend of accessibility, physical properties, and ready copolymerizablllty with most commercially Important monomers. Structure/property relationships for other related monomers will be reported elsewhere. 

Diol Two Component Cure. Amide/blocked aldehyde systems show high reactivity with 1,2 or 1,3 diols and give thermodynamically favored cyclic acetals. As mentioned above, even monomers which self-crosslink poorly because they cannot cycllze to the hemlamidal (I.e., 13, 14) will react efficiently to form crosslinked bis-cycloacetals H In the presence of a tetraol (or, to Impart organic solubility, a blocked tetraol, 15, Scheme 3). 

Post-crosslinkable and substrate reactive polymers are widely used to Improve water and solvent resistance, strength, substrate adhesion and block resistance In binders, adhesives and coatings. The surprisingly rich chemistry of a new class of functional monomers (eg. 1 and 2) related to standard amide/aldehyde (amlnoplast) condensates, but which eliminate aldehyde emissions, was elucidated by monomeric model and mechanistic studies and discussed In the preceeding paper (1). Results with these monomers In copolymer systems are reported here. 

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