THERMOSETTING PLASTICS . THERMOSETTING PLASTICS

PLASTICS THERMOSETTING AND THERMOSETTING PLASTIC. THERMOPLASTIC CAN BE HEATED OVER AND OVER AND SHAPED. THERMOSETTING PLASTIC CAN HEATED AND SHAPED ONCE.

PROPERTIES LIGHT IN WEIGHT EASILY MOULDED AND HAVE EXCELLANCE FINISH VERY GOOD STRENTGHT AND ROUGHNESS CORROSION RESISTANCE LOW THERMAL EXPANSION GOOD WATER RESISTANCE UNBREEAKABLE

AS BUILDING MATERIAL EASY REMOVE AND RECYCLED LOW CONDUCTER OF HEAT THUS USE AS INSULATION MATERIAL LIMITLESS POSSIBILITIES IN DESIGN ACHIVES EASY TO INSTALL THEY DO NOT CORRODE THEY ARE DURABLE PLASTICS ARE LIGHT IN WEIGHT SO THEY EASY TO TRANSPORT

TYEPS OF THERMOSETTING PHENOL FORMALDEHYDE UREA FORMALDEHYDE MALAMINE FORMALDEHYDE POLYURETHANES SILICON RESINS RUBBER

UREA FORMALDEHYDE. IT IS CHEMICAL COMBINATION OF UREA (SOLID CRYTAL OBTAINED FROM AMMONIA) AND FORMALDEHYDE (A IGHLY REACTIVE GAS OBTAINED FROM METHANE It used  vastly in adhesives, wooden carving, Medium-density fiberboard  electrical components and sometimes molded into objects.IT is also known as urea-methanal.

In the plywood industry they are used as adhesives PREPRATION. prepared by the condensation polymerization reaction between urea and formaldehyde in neutral or acidic condition. In the plywood industry they are used as adhesives

PROPERTIES Urea-formaldehyde resin’s include-: ·         It has a very high tensile strength. ·         Urea formaldehyde has the property of  flexural modulus. ·         Has the property of heat distortion temperature. ·         Has the capacity of low water absorption. ·         It has the property of mould shrinkage. ·         Has a property of high surface hardness. ·         It can be elongated  at break ·          It is volume resistance in nature.

USES Urea-formaldehyde resins are used mostly as adhesives for the bonding of plywood ALSO USED IN PARTICLE BOARD, MDF, and molded objects USED IN MOULDING ELECTRICAL DEVICES IN AUTOMOBOLE TYRES IN ORDER TO IMPROVE ITS BONDING OF RUBBER

ADVANTAGES HIGH IN TENSILE STRENGTH WATER PROOF –LOW WATER ABSORPTION VOLUME RESISTANT GOOD ELECTRICAL INSULATOR SCRATCH RESISTANT SURFACE DISADVANTAGES BRITTLE IT DECOMPOSES IN HIGH HUMID TEMPERATURE WHICH LIMITS ITS USAGE AS AN OUTDOOR CONSTRUCTION MATERIAL

SILICON RESINS Silicon is a natural chemical element. Silicone polymers are derived from silicon and so silicone is a  man-made product derived from silicon a natural element. Silicon is generally found in solid crystalline form like sand or glass. Silicone, the product, may be a liquid lubricant, a semi-solid adhesive or a rubber-like plastic polymer Liquid silicone is often used as a lubricant. An example of a  thicker form of rubberized silicone  would waterproof sealant used in bathrooms and window fitting.

USES Because silicones can withstand astonishing stress and temperature extremes, they are used in many aspects of aircraft and spacecraft assembly and maintenance. Adhesives and sealants are used to seal and protect the following from the elements: doors, windows, wings, fuel tanks, hydraulic switches, overhead bins, wing edges, leading gear electrical In building and construction, silicone sealants, adhesives and coatings make construction materials work better and last longer. Silicone adhesives bond diverse materials such as concrete, glass, granite, steel and plastics. This enables innovative architecture and engineering, such as dramatic glass facades or curved and suspended structures Sealants and coatings also protect joints and materials from moisture, heat, corrosion, sunlight, ultraviolet radiation, pollution and other chemicals..

DISADVANTAGES ADVANTAGES Silicone rubber has the ability to resist acids, bases, solvents, chemicals, oils and water. DISADVANTAGES High Viscosity Silicon is also used in making of silicone rubber, which is a polymer used in making of gaskets and insulation. The silicone rubbers are usually bulky and thick in appearance. The rubber has high viscosity and resists the force that allows water to flow easily. Difficulty in Cleaning When silicon is used to provide a seal around the base of the toilet to prevent leakages, it is difficult to install and remove, compared with alternative materials such as caulk. When making certain repairs that require lifting the toilet, it takes a long time to clean the silicone.