Polyethylene adhesion, surface tension effects

From Tables 2 and 3, an epoxide adhesive (surface tension 45 dynes/cm) would not be expected to wet and effectively bond a low energy surface such as polyethylene (critical surface tension 31 dynes/cm). When the polyethylene surface was etched for increasing times in a sulfuric acid-dichromate solution, bond strengths markedly increased and the surface s contact angle with water (increasing polarity) similarly decreased (Fig. 4). ... 

Raney K, Benton W, Miller CA (1987) Optimum detergency conditions with nonionic siufactants II. Effect of hydrophobic additives. J Colloid Interface Sci 119 539-549 Rosen MJ, Wu Y (2001) Superspreading of trisiloxane surfactant mixtures on hydrophobic siufaces 1. Interfacial adsorption of aqueous trisiloxane surfactant -M-alkyl pyrrolidinone mixtures on polyethylene. Langmuir 17 7296-7305 Stevens PJG, Kimberely MO, Mimphy DS, Policello GA (1993) Adhesion of spray droplets to foliage - the role of dynamic surface tension and advantages of organosil-icone surfactants. Pesticide Sci 38 237-245... 

It has generally been observed that urethane systems, which are cured on the surface of some low energy materials, are also free from adhering to them, i.e. they are self-releasing. Materials which show this characteristic relative to urethanes in a very effective way include at least three different types of plastics polytetrafluoroethylene, polyethylene, and polypropylene. These materials all have a defined critical surface tension sc less than about 30 dynes/cm. Assuming that this value is near, the liquid vapor surface tension lv value of an effective IMR urethane systems, then the work of adhesion as given by Equation 4 is as follows ... 

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