Actual Definitions for you.
Micarta is a composite of linen or paper fabric in a thermosetting plastic, originally used in electrical and decorative applications. Micarta was developed by George Westinghouse at least as early as 1910 using phenolic resins invented by Dr. Leo Baekeland. These resins were used to impregnate paper and cotton fabric which were cured under pressure and high temperature to produce laminates. In later years this manufacturing method included the use of fiberglass fabric, other resin types were also used. Today micartas are produced with a wide variety of resins and fibers and the term has evolved to generically refer to most resin impregnated fibre compounds. Common uses of modern micartas are as electrical insulators, printed circuit board substrates, and knife handles.
Phenolic is the name usually given to a resin made of phenol and an aldehyde. It is used anywhere rigid materials are needed, particularly to create moldings for consumer products, for some bearings, for insulation, and as a binder.
Phenolic may also be used as a term to describe the entire class of phenols. These are simple hydrocarbon groups, similar to alcohols. Phenolic compounds are varied, ranging everywhere from the heat agent in chili peppers to dopamine to the cresols from creosote. While the word phenolic may be used individually to refer to these compounds, the term phenolic compound is more appropriate.
Phenolic resins may be made by combining simple phenol with any number of aldehydes, but the combination made with formaldehyde, known as phenolic formaldehyde resin, or PF, is the most widely used. Phenolic resin was the first synthesized resin, and was marketed under the brand name Bakelite, which still exists. The majority of formaldehyde produced is used with phenol and other organic compounds to create resins, which are used extensively in industry.
Phenolic is the material used for most consumer fittings. Plugs on electronic devices, handles for pots and pans, and the screw-tops on most sodas are just a few applications for which phenolic is widely used. Its affordability and the ease with which it is molded make phenolic an ideal candidate whenever a cheap plastic is needed.
Phenolic is also used frequently as the binding agent to hold together composite woods, including chipboard and plywood. Phenolic is somewhat brittle as a binding agent, which is seen by some as a disadvantage, but it lets out very little smoke if it combusts, and at higher grades can be resistant to temperatures in excess of 370°F (185°C). As insulation, phenolic also sees a fair amount of use. Its easy setting and affordability make it ideal in some situations. Phenolic has a high thermal mass, making it a relatively strong thermal insulator in comparison to some other low-cost insulating solutions.
Sheets of material made from phenolic are popular as an alternative to acrylic, because of its high resistance to flexing. These flat plates of material may be used as tables for electric saws, hard floor mats, and even pick guards for guitars. Phenolic sheet is usually made by impregnating a core material, such as paper or fabric, with the resin and then catalyzing it.