Molecular weight distribution in alkyd resins. Part III. Presence of microgel in alkyd resins

Abstract

SynopsisAlkyd resins which have the same overall chemical composition and the same degree of polymerization have been prepared from synthetic mixtures of mono-, di-, and triglycendm of linoleic acid, glycerol, and phthalic anhydride. The properties of these resins difiered significantly. Microgel particles are present in all resins, but the quantity and size of the gel particles is a function of the glyceride composition. The concept of microgel is used to explain the solution and film forming properties of these resins. Examination of a range of commercially available alkyd resins has shown that microgel particles are present where the functionality is greater than two.

Atomic force microscopy and scanning electron microscopy characterization of the controlling of surface morphology of epoxy‐amine‐cured spin‐coated films

“…The 10 μm × 10 μm scan shows the larger nodules range upwards of 100 nm in height and more than 2 μm in width. Though post‐curing of the epoxy normally results in increased mechanical properties as additional cross‐linking occurs, 52,67,68 several authors have reported nodular structures do not change with post‐cures even above the glass transition temperature T g 34,35,69,70,71 . Though the reason for this is not fully understood, it appears nodular formation occurs at random locations on the surface before gelation.…”

“…Though post-curing of the epoxy normally results in increased mechanical properties as additional cross-linking occurs, 52,67,68 several authors have reported nodular structures do not change with post-cures even above the glass transition temperature T g . 34,35,69,70,71 Though the reason for this is not fully understood, it appears nodular formation occurs at random locations on the surface before gelation. Though the exact reason is unknown, the air pockets generated during high shearing, which are not completely removed may play a role, as these pockets possibly contain higher moisture and CO 2 content than the bulk.…”

Microgels-Intramolecularly Crossünked Macromolecules with a Globular Structure

“…Microgels have also been detected as a component of alkyd resins, an early but still important binder of organic coatings [316][317][318][319][320][321] and are accountable for their ability to fill pores, fissures and other irregularities of the substrate such as wood. This property may be explained by the size of the microgels which pre vents the paint becoming soaked up by the substrate.…”

Epoxy Resins

“…and draws attention to the parallel between the cure and the polyesterification reactions of alkyd resins. Solomon et al 206 have invoked the formation of microgel particles formed from micelles at whose surface rapid polyesterification occurs.…”