MEMS 1 Lesson 1 - Plastics (1) PDF

Baliuag University - Tumana Campus College of Environmental Design and Engineering Second Trimester A.Y. 2024-2025 Ecat, John Rovic T. (BSME3) THERMOPLASTIC:...

Baliuag University - Tumana Campus College of Environmental Design and Engineering Second Trimester A.Y. 2024-2025 Ecat, John Rovic T. (BSME3) THERMOPLASTIC: Plastics that can be deformed easily upon heating and can be bent easily. Linear TOPICS: polymers and a combination of linear and 1. What is Plastic? cross-linked polymers come under 2. Types of Plastic thermoplastics. Example: PVC, nylon, a. Thermoplastic polythene, etc. b. Thermosetting 3. Recycling of Plastic THERMOSETTING: 4. Properties of Plastic 5. Seven Types of Plastic Plastics that cannot be softened again by heating once they are moulded. Heavily PLASTICS: cross-linked polymers come under the category of thermosetting plastics. The word, plastic, was derived from the Example: Bakelite, melamine, etc. Bakelite word ‘Plastikos’ meaning ‘to mould’ in is used for making electrical switches Greek. whereas melamine is used for floor tiles. Plastic is defined as a material that contains an essential ingredient an RECYCLING OF PLASTIC: organic substance of large molecular weight. It is also defined as polymers of Recycling of plastic is very important. If long carbon chains. they are not recycled at the proper time, Plastic was discovered by famous German then they get mixed with other chemicals chemist Christian Schonbein in 1846. or materials and hence become more Plastics were actually discovered difficult to recycle and become a source accidentally. Christian was experimenting of pollution. in his kitchen and by accident, he spilt a They are non-biodegradable, and they do mixture of nitric acid and sulphuric acid. not get decomposed by the microbial To mop that solution (a mixture of nitric action. and sulphuric acid) he took a cloth and To avoid this, it is important to use after moping he kept it over the stove. biopolymers or biodegradable polymers. After some time, the cloth disappeared and from their plastic got its name. PROPERTIES OF PLASTIC: Strong and ductile. TYPES OF PLASTICS: Poor conductors of heat and electricity. Depending on physical properties, plastics Easily moulded into different shapes and are divided into two types: size. Thermoplastic Resist corrosion and are resistant to many Thermosetting chemicals.