Ex:- Bakelite (used in electrical insulators), Melamine etc. Understand the Key Differences Between Thermoplastic and Thermosetting Plastic with detailed explanations and examples. Bakelite; Melamine; Two example of each type of plastics are given below : Polythene – making polythene bags, bottles etc, Polyvinyl chloride – making electric wires, pipes, garden hoses etc. a) Nylon. Another reason for application of cocondensates is their price; for example, UF-resins are cheaper than MF- or PF-resins. Thermoset plastics are frequently used for sealed products due to their resistance to deformation and are also among some … It is further classified into, Homopolymers:Polymers formed by the polymerisation of a single monomeric species. Question 1 is of 20 marks having four subparts, all of … a) Thermosetting plastics. Long-term behaviour . Yogita Ingle 4 months ago. As we all know, emulsifier can reduce the interfacial tension and increase the contact area between foaming agent and MF resin which is benefit to foaming. 59, 69, 70 … This document is highly rated by UPSC students and has been viewed 1 times. These polymers have tensile strength, less elasticity, high melting point, and low solubility. Contributors and Attributions. We have provided Polymers Class 12 Chemistry MCQs Questions with Answers to help … The first plastic was invented in 1862 derived from Cellulose, a substance found in plants. Which of the following characteristics does not affect the properties of plastics? Phenol–melamine–formaldehyde resins (PMF-resins) show, in some respects, better properties than the corresponding MF- and PF-condensates. Choose the correct answer: The synthetic plastic used for making insulation cover in electrical wires and cables is . For example, glycerol , isocyanate  as well as substituted melamine  had been added into MF resin to improve its flexibility. The first gepletely manmade plastic was discovered in 1907 by Leo Baekeland, called Bakelite. Recycling of Plastic. These resins are resistant to the atmosphere and chemical corrosion, have fairly light weight, low heat conductivity, high structural strength and excellent electrical insulation. The plastic industry gained momentum, slowly moving into the homes … It is … It is made from melamine and formaldehyde by condensation of the two monomers. These include cellulose, lignin, and various resins. d) Silk 10 The coating on modern non- stick cookware and electric iron is of. EXAMPLE 3. polyethyleneterephthalate: n ... Bakelite, Melamine, polycarbonates, polyurethanes, epoxies. Examples include polyesters, e.g. 8 Bakelite and Melamine are examples of. Good examples are melamine (kitchen worktops), Bakelite (black saucepan handles), polyester and epoxy resins. Thermoplastic Polymers… … If they are not recycled at the proper time, then they get mixed with other chemicals or materials and hence become more difficult to recycle and … It is used to make electrical switches and handles of utensils. Thermosetting plastics are having highly branched chain molecules with extensive cross linking and if heated becomes infusible and cannot be reused. Examples – Bakelite, melamine, etc. c) Melamine plastic. Melamine is resistant to fire and is hence used for making utensils. Melamine definition: a colourless crystalline compound used in making synthetic resins ;... | Meaning, pronunciation, translations and examples These results relate to a few grades only and cannot be generalized. Bakelite, Resinox and Durez are examples of phenolic resins of the molding type. For example: Bakelite and melamine. Polyester resin is mixed with glass fibre to make GRP used for boatbuilding and fishing rods. Polymerization is the process by which monomer molecules are reacted together in a chemical reaction to form a polymer chain (or three-dimensional networks). Wood resins are polymers of a simple hydrocarbon, isoprene. These polymers are brittle and hard. It is used for making electrical switches, handles of various utensils, etc. They are held together through hydrogen bonds and/or dipole- dipole attraction.. Some examples include, bakelite and melamine formaldehyde resin. Examples … The dangerous nature of Bakelite is from different sources: manufacturing, collecting and disposing. Melamine is used for making floor tiles, kitchenware etc. The fully natural fibreis called _____ A natural fibre obtained by boiling of cocoons is called _____ Answer: Raincoat; Resin codes; polymer; plant … Some examples include, nylon, cellulose, wool, terylene, and silk. A _____ is a long chain made up of many repeated small units called monomers. Typical UL … Bakelite is a man-made (synthetic) material while Melamine occurs naturally (is organic). It is used in making plastic toys. Bakelite is a poor conductor of heat and electricity. Give examples which indicate that nylon fibres are very strong. A) Bakelite B) Melamine C) Teflon D) None of these 4. For example, the solid parts of all plants are made up of polymers. Melamine-Formaldehyde Resins Properties. Cellulose is a polysaccharide, a polymer that is composed of sugar molecules. For example: melamine, Bakelite etc. But different kinds of emulsifiers had dif … Based on the mode of polymerisation, it is classified into I. examples are bakelite and melamine. Another familiar isoprene polymer … Bakelite is used for making electrical switches whereas melamine is used for floor tiles. Question 13. Write the monomers used for gettingThe following polymers: (i) Polyvinylchloride (ii) Teflon (iii) Bakelite Ans: 15.13. It is used in electric switches, plugs, handles of pressure cooker and tea kettle, radio and TV cabinets, etc Bakelite, Melamine, etc are some examples of it. MCQ Questions for Class 12 Chemistry with Answers were prepared based on the latest exam pattern. 18 g water-thinnable phenolic resol resin (from Bakelite); 2 g water-thinnable melamine resin (from Vianova); 2 g 1,2-octanediol; 5 g 1,2-hexanediol; 1 g zinc glycerophosphate; is made up to 100 g with water. The formation process of these two types of plastics also differs. It is further classified into, Homopolymers:Polymers formed by the polymerisation of a single monomeric species. Write the name and structure of one of the common initiators used in free radical addition polymerisation. a) Terrycot. Its good fire retardant properties are due to … Answered By It is used in making bottles. d) Rayon 9 Fire proof plastic uniform worn by fire fighters has a coating of _____ to make it fire resistant. ISC Chemistry Previous Year Question Paper 2019 Solved for Class 12 Maximum Marks: 70 Time allowed: 3 hours Candidates are allowed additional 15 minutes for only reading the paper. Lignin consists of a complicated three-dimensional network of polymers. Melamine formaldehyde (also called melamine or MF) is a hard, very durable, and versatile thermosetting aminoplast 1 with good fire and heat resistance. Answer: Thermosetting – bakelite, melamine Thermoplastics – combs, toys. Question: What is the … Dec 21, 2020 - NCERT Gist: Synthetic Fibres and Plastics UPSC Notes | EduRev is made by best teachers of UPSC. Epoxy resin plus carbon fibre is … Synthetic condensation polymers have a wide array of household, industrial, commercial, and medical uses and applications. Examples: Polythene, Polyvinyl Chlorides, etc. Examples are bakelite, melamine-foimaldehyde polymer etc. Bakelite is a thermosetting plastic, it cannot be molded again whereas Melamine, being a thermoplastic, can be molded any number of times adn reshaped. 0 Thank You. These new plastics could be … EXAMPLE 2. Melamine and bakelite are the examples thermosetting plastic. Bakelite is a thermosetting plastic which is a poor conductor of heat and electricity. A) PVC B) Bakelite C) Melamine D) Polythene 5. 36.4.1 Phenol–melamine–formaldehyde resins. Composites are made by mixing materials together to get enhanced properties. Fibers. For example, Bakelite jewelry is more rare than, say, dishes or cookware. source:www.intercosmo.net ; Thermoplastics: The plastic which becomes soft on heating and can be remolded into desired shape is called thermoplastic. Ans: Thermoplastics is a plastic which can be … Since Bakelite is a … Ans: 15.14. It is used for packaging many goods like container etc. They must NOT start writing during this time. Bakelite is used for making electrical switches, handles of various utensils etc. 27 g water-thinnable phenolic resol resin (from Bakelite); 3 g water-thinnable melamine resin … The continuous use temperatures in an unstressed state range from: • 80–150 °C for melamines • 70–100 °C for urea-formaldehydes. 15.12. Bisphenal A (BPA) 0 Thank You. Example: Bakelite, melamine, etc. Suryansh Singh 4 months ago. 30) Why are thermoplastics not used for making frying pan handles ? Based on the mode of polymerisation, it is classified into; Addition polymers: Polymers are formed by the repeated addition of monomers with double and triple bonds. Examples … Melamine and Bakelite are two examples of thermoplastics. Based on the type of … b) Rayon. Why is it hazardous? Why are the chemicals in the laboratory stored in plastic containers ? All questions are compulsory. A) cellulose B) starch C) Both A and B D) silk … c) Nylon. 3] Based on Mode of Polymerisation. Bakelite is used for making electrical switches and switchboards because it is a poor conductor of heat and electricity. Addition polymers: Polymers are formed by the repeated addition of monomers with double and triple bonds. Bakelite and melamine are the examples of … They have a very strong intermolecular force. b) … Melamine is a thermosetting plastic which is resistant to fire and can tolerate heat better than other plastics. Plastics which do not get deformed or softened on heating when mold once, are called thermosetting plastics. _____ are used to identify different types of plastics. Melamine is a compound used in some plastic products, such as dishes, utensils, and more. For example: Bakelite, formaldehyde polymer, glyptal, melamine-formaldehyde polymer. Glass fibre reinforced melamine: example of modulus retention versus temperature. Examples – Bakelite, melamine, etc. b) Silk. Uses. Check the below NCERT MCQ Questions for Class 12 Chemistry Chapter 15 Polymers with Answers Pdf free download. Notes/Highlights. 6.3 Examples of Common Defect Types 7 Disclaimer / Resources 8 Product Overview Title: Ford 1.0 I3 MMLV ... [EP], unsaturated polyester [UP], melamine phenolic [MP] and phenolic [PF] resins allow products to be mass produced in an infinite variety of contours and forms. They stand up well in most plating baths and alkaline cleaners, … Color Highlighted Text Notes; Please Sign In to create your own … How does the … Bakelite is a thermosetting phenol formaldehyde resin, formed from a condensation reaction of phenol with formaldehyde. Bakelite and melamine are examples of thermosetting plastic. Choose the correct answer: Natural polymer occurring in plant is . Answer: ... Classify the following into thermosetting and thermoplastics-combs, bakelite, melamine, toys. It resists fire and can tolerate Hence, option C is correct. _____ is an example of polyester fabric. The market value is extremely high, due to the retro feel and limited quantities of certain products. William Reusch, … It is used to make floor tiles, kitchenware and fire resistant fabrics. Dimensional stability, surface hardness and … We'll discuss whether it's safe to use and any risks. Melamine is a versatile material. Recycling of plastic is very important. In the growing consumer market of the 1930s and after, Bakelite faced competition from other thermosetting resins such as urea formaldehyde and melamine formaldehyde and from new thermoplastic resins such as cellulose acetate, polyvinyl chloride, polymethyl methacrylate, and polystyrene.