Thermoplastic are those which are obtained from the substituted derivatives of ethylene which can be made to polymerize under the influence of heat and catalyst. These materials are softened by heat and affected by certain solvent. A notable feature of these resins is the ability of their scrap or rejects to be reworked along with the new material. Cellulose nitrate (celluloid) and polythene are the example of these materials. Where as thermosetting are those which are formed into shape under heat and pressure and results in a permanently hard product. The heat first softens the material, but as additional heat and pressure is applied, it becomes hard phenol formaldehyde (bakelite). Phenol furfural (Durite) is the example of thermosetting plastics. The comparison between thermo plastic and thermosetting plastic is given below.
|S.No||Thermo Plastic||Thermosetting Plastic|
|1.||They can be repeatedly softened by heat and hardened by cooling.||Once hardened and set, they do not soften with the application of heat.|
|2.||They are comparatively softer and less strong.||They are more stronger and harder than thermoplastic resins|
|3.||Objects made by thermoplastic resins cannot be used at comparatively higher temperature as they will tend to soften under heat.||Objects made by thermosetting resins can be used at comparatively higher temperature without damage|
|4.||They are usually supplied as granular material||They are usually supplied in monomeric or partially polymerized material form in which they are either liquids or partially thermoplastic solids.|
|5.||Applications. Toys, combs, toilet goods, photographic films, insulating tapes, hoses, electric insulation, etc.||Applications. Telephone receivers, electric plugs, radio and T.V. cabinets, camera bodies, automobile parts, tapes, hoses, circuit breaker switch panels, etc.|