Green strength enhancement

Microscopic studies of acrylic/phenolic dispersion blends show the phenolic particles dispersed in the acrylic matrix. This and the data of Table 1 suggest at least three possible mechanisms for green strength enhancement. 1) The phenolic particles may be serving merely as fillers to improve the wet strength of the system. 

Introduction of ionic groups or proteins into polymers (forming ionomers) leads to physical associations at the temperature of use [110, 111]. For example, Surlyn (DuPont) is a copolymer of ethylene and methacrylic add that shows enhanced zero-shear viscosity and elastomeric green strength. Viscoelastic characteristics are also enhanced due to loss of associations at the appropriate dissociation temperature. Ion pair associations are exploited to obtain misdbUity in otherwise immiscible polymers [112],... 

How important is the particulate nature of the phenoic dispersion to its role of enhancing green strength in water-borne systems Is it simply serving as an inert filler to enhance wet strength or... 

Fig. 4. The labile crosslinking reaction for enhancing green strength. Reproduced with permission from Rubber Chem. Techno/.

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