Pre-treatment of polymers

See also Pre-treatments of polymers and Surface characterization by contact angles - polymers. 

Chemical modification is possible using Electrochemical pre-treatments of polymers,... 

The first method, although effective, was soon abandoned for safety reasons, while the use of chromic acid has been largely discontinued. The other two have remained the most widely used pre-treatments, not only for LDPE but also for high-density polyethylene (HDPE) and polypropylene (PP). Other methods have been found to be effective, but for reasons of cost, safety or convenience, they have not been widely used. The pre-treatments include fuming nitric acid, potassium permanganate, ammonium peroxydisulphate, ozone, fluorine, peroxides, UV radiation, grafting of polar monomers, plasmas (see Plasma pretreatment), electrochemical oxidation (see Electrochemical pre-treatment of polymers) and the use of solvent vapours. The corona, flame and plasma methods and the use of trichloroethylene are now discussed briefly the latter is included because it involves a different mechanism. 

The use of low-pressure plasmas is becoming an increasingly important method to pre-treat polyolefins. An interesting comparison of dry pre-treatments is given in reference. See also the more general article Pre-treatments of polymers. 

The more common environmental problem with metal joints is attack by water. In addition to alloy composition, pre-treatment and primer, durability is affected by the adhesive used (see Pre-treatment of metals prior to bonding. Pre-treatment of polymers. Primers for adhesive bonding). Sell has ranked adhesives in the order of durability they provide with aluminium substrates ... 

Related articles are Adsorption theory of adhesion, Contact angles and interfacial tension. Pre-treatments of polymers. Surface energy. Wetting and spreading. 

These ideas are farther developed in other articles, in particnlar. Surface characterization by contact angles - polymers. Wetting and spreading, Wetting and work of adhesion, Contact angles and interfacial tension. Pre-treatments of polymers and Pretreatment of metals prior to bonding. 

Electrochemical pre-treatment of polymers R H DAHM Recently developed surface treatment methods... 

Flame treatment D BRIGGS Pre-treatment of polymers, scope... 

Pre-treatments of polymers D M BREWIS Effects of solvent, mechanical, oxidative and plasma treatment... 

---