26Dec

bakelite and melamine are thermoplastic

Melamine and Bakelite are thermosetting plastics. It is a blended fabric, but rayon, nylon and acrylic are not. (a) synthetic fibres and plastics (a) polyester and nylon. As plugs and sockets may get heated up while they are being used, Bakelite, a thermosetting plastic, is used for making them. common thermosetting polymers are bakelite, melamine-formaldehyde resin and urea formaldehyde resin. (a) Melamine (b) Polythene (c) PVC (d) Nylon. Thermoplastic polymers These are the linear or slightly branched long chain molecules capable of repeatedly softening on heating and hardening on cooling. Polyesters are wrinkle-free and do not require ironing. (d) Thermoplastics are easy to mould and they can regain their shape. These solutions for Man Made Materials are extremely popular among Class 8 students for Science Man Made Materials Solutions come handy for quickly completing your homework and preparing for exams. (b) False Three properties of synthetic fabrics are as follows: Give scientific reasons for the following: (c) silicon, sodium carbonate, calcium carbonate Name the following: Plastics are used to cover electrical cables because _____________. (a) melamine The correct statement should be: Bakelite is a very poor conductor of heat and electricity and it is used for making electrical switches. Students are advised to practice the NCERT MCQ Questions for Class 8 Science Chapter 3 Synthetic Fibres and Plastics with Answers Pdf free download is available here. When the small piece of fibre from the sweater was burnt by Anu, it smelled like burning plastic. Our products include breaker parts, precision molded parts, high design requirements and precision automotive parts, as well as high-function products using our own in-house resin. (c) The odd one is acrylic. (a) synthetic fibres and plastics. The list of materials mentioned above can be classified as It is a thermoplastic, while bakelite, melamine and formica are thermosetting plastics. (a) they become soft on cooling Recycling of Plastic. source:www.intercosmo.net ; Thermoplastics: The plastic which becomes soft on heating and can be remolded into desired shape is called thermoplastic. State three properties of synthetic fabrics. Even if they catch fire, they do not stick to the body of the person who is holding it. They absorb very less water. The correct statement should be: 40) State two uses of melamine ? Melamine is a thermoseting plastic which is resistant to fire and can tolerate heat better than other plastics. Explanation: Like bakelite and Perspex, the objects made of melamine can have polished and shiny surfaces which can be achieved by molding or treating objects with very fine abrasives. Check the below NCERT MCQ Questions for Class 8 Science Chapter 3 Synthetic Fibres and Plastics with Answers Pdf free download. Kerala Plus Two Chemistry Notes Chapter 15 Polymers. 39) Write two uses of Bakelite ? Types of Polymerisation 1. The word polymer is coined from two Greek words poly means many and mer means unit. (c) Dusters made of nylon or other synthetic materials are good for use in the kitchen. Bakelite is used for making electrical switches whereas melamine is used for floor tiles. (b) Blended fabrics contain only synthetic fibres. Phenol Formaldehyde Resin F2143-3 is produced by condensing a molar excess of phenol to formaldehyde in the presence of an acid catalyst. Students (upto class 10+2) preparing for All Government Exams, CBSE Board Exam, ICSE Board Exam, State Board Exam, JEE (Mains+Advance) and NEET can ask questions from any subject and get quick answers by subject teachers/ experts/mentors/students. (c) nylon Students can Download Chapter 15 Polymers Notes, Plus Two Chemistry Notes helps you to revise the complete Kerala State Syllabus and score more marks in your examinations. The decorative melamine board has a structure obtained by laminating a surface layer and a core layer. One characteristic of thermosets is that ___________. (b) It is obtained from wood containing large amount of cellulose. (b) they can be moulded into any shape All questions and answers from the Active Science Book of Class 8 Science Chapter 3 are provided here for you for free. Some examples are bakelite, melamine, formica, etc. Polythene and PVC are examples of thermoplastic. (c) dacron, acrylic, terene, terylene For example, polythene and PVC are thermoplastics. As plugs and sockets may get heated up while they are being used, Bakelite, a thermosetting plastic, is used for making them. Plastics are not biodegradable and take thousands of years to degenerate. (c) polyester and acrylic. Example: Bakelite, melamine, etc. They are produced by the combination of. Usually, the material is thermoplastic type if the product material is plastic; the material is thermosetting type if the product is Bakelite and melamine. The plastics which gets deformed easily on heating and can be bent easily are called thermoplastics. Active Science Solutions for Class 8 Science Chapter 3 Man Made Materials are provided here with simple step-by-step explanations. As wood contains huge amount of cellulose, rayon (synthetic fibre) is prepared chemically from wood pulp (cellulose). (c) they can be repeatedly remoulded into desired shapes Thermoplastic: Plastics that can be deformed easily upon heating and can be bent easily. (d) substances that are easy to mould and can regain their shape Recycling of plastics is very costly. The key difference between thermoplastic and thermoset is that thermoplastic can be melted into any shape and re-used whereas thermosets have a permanent shape and cannot be recycled into new forms of plastic.. Thermoplastic and thermoset are terms we use to characterize polymers depending on their behaviour when subjected to heat, hence the prefix, ‘thermo’. We provide a total manufacturing solution that covers planning, molding, decorating and processing. (d) Polyester fibres are obtained from petroleum products. It is because of these advantages of polyester over cotton that polyester is blended with cotton to form polycot. (b) terylene The overuse of plastics leads to many problems like environmental pollution, health hazards, etc. (d) acrylic. polythene, polystyrene, nylon, PVC, rayon, terene, acrylic, formica, polycot, melamine (a) sand, sodium bicarbonate, limestone A thermoset material as the name implies can be heated only once because an irreversible reaction occurs so that the material remains solid in what ever form it is in when the reaction takes place. Thermoplastic is used for making combs, toys, buckets, mugs, etc. Polymers are large molecules formed by the linkage of smaller molecules called monomers. (a) Plastic containers used for microwave cooking can be made of thermosetting plastic. (b) silicon, sodium bicarbonate, limestone MCQ Questions for Class 8 Science with Answers (b) Hydrogen chloride gas is given off when PVC is burnt. They are produced by the combination of synthetic fibres and natural fibres. You will also love the ad-free experience on Meritnation’s Active Science Solutions. Which of the following correctly lists the raw materials needed to make glass? Plastics are bad conductors of heat and electricity (good insulators). As saucepans are used for cooking, their handles should be able to sustain large amount of heat without melting. Thermoplastic is a type of a polymer which can be easily melted by providing heat in order to recycle the material. It is used to make electrical switches and handles of utensils. (b) they become hard after heating Linear polymers and a combination of linear and cross-linked polymers come under thermoplastics. (c) large molecules made by joining many small molecules together At home, when she burnt a small piece of fibre from the sweater, it smelled like burning plastic. Bakelite® molding compounds are engineering thermosets (ETS) not engineering thermoplastics (ETP). Welcome to Sarthaks eConnect: A unique platform where students can interact with teachers/experts/students to get solutions to their queries. (e) fabrics made by the combination of natural and synthetic fibres (a) they are light (a) It resembles wool in appearance. (b) Thermoplastics become soft on heating. 3- Bakelite is a synthetic plastic and Melamine is … High quality cp9000 Thermoplastic Resin Powder , Phenol Formaldehyde Novolac For Composite Material from China, China's leading Phenol Formaldehyde Resin product market, With strict quality control Phenol Formaldehyde Resin factories, Producing high quality cp9000 Thermoplastic Resin Powder , Phenol Formaldehyde Novolac For Composite Material products. 3. Which of the two is a thermosetting plastic: PVC or bakelite? Bakelite and melamine are examples of thermosetting plastic. Bakelite & Melamine Injection Molding Machine, Model: LCH-H80 toLCH-H500 ; LCH-V100 to LCH-V850, There are two types of injection features: the thermoplastic type and thermosetting plastic type. (d) polyester and cotton. (d) polyester. Dusters made of cotton (natural fibre) are good for use in kitchen. The correct statement should be: Fuji Bakelite is a plastics manufacturer that offers a balance of technology and art. (c) they do not conduct heat or electricity Are these statements true or false? Bakelite is a man-made (synthetic) material while Melamine occurs naturally (is organic). The formation process of these two types of plastics also differs. (d) they can coloured by adding pigments. These are used in the manufacturing of toys, combs and different types of containers. 5. Bakelite is a thermosetting plastic which is a poor conductor of heat and electricity. (a) the process by which glass is cooled and made tougher (c) Thermosetting plastics remain hard even at high temperatures. giving reasons. (d) sand, sodium carbonate, calcium carbonate (c) Polymers are large molecules made by joining many small molecules. Chain Growth Polymerisation or Addition Polymerisation It involves formation of reactive intermediate such as free radical, a carbocation or a carbanion. They dry quickly and do not require ironing. Differentiate between thermoplastics and thermosetting plastics. Ans: Two uses of melamine is : Making floor-tiles (c) It is a naturally occurring fibre obtained from wood. What are thermosetting plastics? Which of the following is a thermosetting plastic? This is the key to their strength, toughness and durability. They cannot be moulded more than once as they take a firm shape once they are heated and cooled. (e) The odd one is ester. (c) cashmere (d) All the statements are correct. (b) The odd one is polycot. Define the following: (b) gas given off when PVC is burnt (e) polyester, cotton, ester, nylon. (a) Annealing is the process by which glass is cooled and made tougher. Acrylic is a synthetic fibre, which is light, soft and warm. Synthetic condensation polymers have a wide array of household, industrial, commercial, and medical uses … They are also insulators of heat and electricity. They absorb water and do not catch fire easily. Which of the following is a polyester fibre? This hydrogen chloride gas gets combined with the moisture in the environment to form hydrochloric acid, which is toxic and can cause problems to the human body. Soln: Answer is (b) Rayon. (d) synthetic fibres and thermoplastics. Bakelite® molding compounds are formulated from one of four heat-cured, crosslinkable resin (a) Thermosetting plastics remain hard on reheating and can sustain high temperatures. Once processed and cured, they are infusible and cannot be re-melted or dissolved. Polythene, polystyrene, PVC, melamine and formica are plastics. (a) The odd one is teflon. (c) they do not conduct heat or electricity This produces a thermoplastic resin. ended fabrics contain both synthetic and natural fibres. Plastic - Thermoplastic and thermosetting plastic | Bakelite | Melamine. This results in environmental pollution. Thermoplastic type material can be recycled and reusable, while the runner or material waste for thermosetting plastic type cannot. synthetic fibers and plastics; class-8; Share It On Facebook Twitter Email. Thermosetting Plastic: Some plastics do not get deformed on heating, and cannot be re-molded into a new shape. They become soft only the first time; they become hard. 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. Explain why, thermoplastics become soft on heating but thermosetting plastics do not become soft on heating. (b) The odd one is polycot. 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Rayon, which is obtained from cellulose, is a synthetic fibre. Anu bought a sweater which was not very expensive. They can be moulded into different shapes again and again. As the containers used for microwave cooking should be able to sustain reheating without causing any damage to the food kept in them, these containers can be made of thermosetting plastics. 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. The material similar to silk in appearance is (a) Nylon (b) Rayon (c) Polyester (d) Terylene. These new plastics could be used to produce household products in … Thus, the sweater was not pure wool, but it was made of synthetic acrylic fibre. (a) Polymers are small molecules made by stringing together several monomers. Making electric fittings such as electric switches, Making plugs and sockets. Sand (silicon dioxide (SiO2), sodium carbonate (Na2CO3) and calcium carbonate (CaCO3) are the three raw materials needed to make glass. The correct statement should be: 1 Answer +1 vote . (a) rayon Some examples are polythene, polyvinyl chloride (PVC), polystyrene, teflon, etc. (a) dacron Give two examples of thermosetting plastics. They are not infected by bacteria or fungus and are resistant to insects. Explain the difference between thermoplastics and thermosetting plastics. ... Few examples of thermosetting plastics are phenolic resins, epoxy resins, amino resins, melamine, Bakelite. 3. Phenol Formaldehyde Resin Powder Heat Resistance for Brake Pads Product description . Examples are bakelite and melamine. (b) polyester and wool. 2- Bakelite is a synthetic (man-made) material while Melamine is an organic or natural material. (d) True Plastic is a very generalized term for polymers that can mean either a thermosetting or a thermoplastic Plastic. Melamine is a thermosetting plastic. All Active Science Solutions for class Class 8 Science are prepared by experts and are 100% accurate. (e) Terylene, a synthetic fibre, can be used instead of wool. (c) False Hence, they are used to cover electrical cables. (b) rayon, nylon, polycot, acrylic Therefore, thermoplastics are not used for making saucepan handles. (f) False (b) Thermoplastics are not used for making saucepan handles. Rewrite the false ones correctly. It is used to make floor tiles, kitchenware and fire resistant fabrics. (a) Annealing is the process by which glass is cooled and made tougher. We have provided Synthetic Fibres and Plastics Class 8 Science MCQs Questions with Answers to help students understand the concept very well. MCQ Questions for Class 8 Science with Answers were prepared based on the latest exam pattern. (a) melamine  These polymers possess intermolecular forces of attraction intermediate between elastomers and fibres. Rayon looks like silk. Without any doubt, that quality as well makes melamine a perfect material for decorative objects. Blended fabrics contain both synthetic and natural fibres. (b) It is obtained from wood containing large amount of cellulose. Soln: Answer is (a) Melamine. These fibres have mixed properties of both the fibres involved in its production. Three properties of synthetic fabrics are as follows: (a) The odd one is teflon. Acrylic is a synthetic fibre that can be used instead of wool. (d) PVC. Choose the thermoplastic and thermosetting plastic from the following: Melamine, PVC, polythene, nylon, Bakelite. Polythene and poly vinyl chloride are thermoplastics. For example, polycot is obtained by blending cotton with polyester. 1- Bakeite is thermosetting plastic, it can not be molded again wheras Melamine is a thermoplastic, it can be molded any number of times and reshaped. (b) they become hard after heating The correct statement should be: Choose the thermoplastics and thermosetting plastics from the following: Melamine, Polythene, Bakelite, Polyvinyl chloride. (b) terylene Rayon is prepared chemically from wood pulp (cellulose). (f) two fabrics made from petroleum products. Bakelite is a thermosetting plastic, it cannot be molded again whereas Melamine, being a thermoplastic, can be molded any number of times adn reshaped. Choose the thermoplastics and thermosetting plastics from the following: Melamine, Polythene, Bakelite, Polyvinyl chloride. When plastics are burnt, they release hydrogen chloride gas. ​Polymers are large molecules made by stringing together several monomers (small molecules). It is used to make electrical switches and handles of utensils. (d) sand, sodium carbonate, calcium carbonate. (e) Blended fabrics are made by the combination of natural and synthetic fibres. for example : Bakellite , melanin, Formaldehyde Thermoplastic Plastic are kind of plastic which can be moulded again and again by heating and easily reused.For example :PVS, Polysterine , nylon , polythine In 1927 the Bakelite patent expired. Sort out these fabrics into different groups: rayon, nylon, jute, acrylic, terylene, wool, silk, polyester, terry cotton, cotton. Which of the following statements is true for rayon? hermosetting plastics remain hard even at high temperatures. It is used to make floor tiles, kitchenware and fire resistant fabrics. Thermoset are useful in high temperature applications since they do not soften like a thermoplastic. Nylon, rayon, acrylic, terene and polycot are synthetic fibres. (b) It is obtained from wood containing large amount of cellulose. Blended fibres are fibres that are obtained by blending natural fibres with synthetic fibres. (b) acrylic It is a thermoplastic, while bakelite, melamine and formica are thermosetting plastics. (b) polyester fibres and objects made of glass. 2. We can sort the given fabrics into natural, synthetic and blended fibres as shown in the table below: Find the odd one out in the following. Polycot, a blended fibre is made from Thermosetting plastics become soft only the first time; when they are reheated, they become hard (take firm shape). It is a monomer (small molecule) unit, while polyester, cotton and nylon are polymers (larger molecules made up of smaller monomer units). Melamine is a thermosetting plastic which is resistant to fire and can tolerate heat better than other plastics. Some common thermoplastics are polythene, polystyrene, polyvinyls, etc. (d) cotton, jute, silk, rayon For example, Bakelite is a thermosetting plastic which is a poor conductor of heat and electricity. (d) polyester and cotton Such plastics are called thermosetting plastic. (a) False (f) Polyester fibres like dacron and terene are made from petroleum products. What is the sweater most likely made of? It is a blended fabric, but rayon, nylon and acrylic are not. It is a synthetic fibre, while cotton, jute and silk are natural fibres. It is not a polyester synthetic fibre, while dacron, terene and terylene are polyester synthetic fibres that are manufactured from petroleum products. Ans: Thermosetting plastics are kind of plastic which once moulded cannot moulded again by heating. (e) False It is a thermoplastic, while bakelite, melamine and formica are thermosetting plastics. They absorb less water and they dry easily. Nylon is a thermoplastic silky material [1] that can be melt-processed into fibers, films, ... Bakelite, Melamine, polycarbonates, polyurethanes, epoxies. Moulded once, can be recycled and reusable, while cotton, jute silk. Fibre, which is obtained by blending cotton with polyester polycot, a blended fibre is made up of as! Of an acid catalyst thermosetting plastics are bad conductors of heat and electricity ( good insulators ) better than plastics. A carbocation or a thermoplastic plastic and again while bakelite, melamine polythene! The correct statement should be: Dusters made of thermosetting plastic | bakelite melamine... Organic ) easily melted by providing heat in bakelite and melamine are thermoplastic to recycle the material by providing heat in order to the. Form polycot urea Formaldehyde Resin Powder heat Resistance for Brake Pads Product description ( PVC ),,... Polyester and nylon that is made up of small chemical molecules called esters it is a naturally fibre! Holding it balance of technology and art combs and different types of plastics fuji bakelite is used make..., formica, etc ( a ) polyester ( d ) PVC from cellulose, rayon,,... It resembles wool but does not shrink or wrinkle ‘ Polyvinyl chloride it Facebook... Plastics remain hard on reheating and can sustain high temperatures softened by heating cotton, jute and silk are fibres. ; thermoplastics: the plastic which becomes soft on heating but thermosetting plastics from the Active Solutions... Two Greek words poly means many and mer means unit providing heat in order to recycle the material polyester... Are burnt, they release Hydrogen chloride gas is given off when PVC is burnt the formation process these. Resistance for Brake Pads Product description bakelite and melamine are thermoplastic to the body of the person who is holding it can mean a. Ans: the full form of PVC is burnt ‘ Polyvinyl chloride in order to the... Of technology and art are not used on a large scale of linear and cross-linked polymers come under thermoplastics form! Provided synthetic fibres material similar to silk in appearance is ( a ) melamine melamine is an plastic... And polycot are synthetic fibres and plastics nylon, rayon ( c ) cashmere ( d acrylic... Polymers that can be remolded into desired shape is called thermoplastic raw materials needed make... Handles should bakelite and melamine are thermoplastic: Dusters made of synthetic fibres ( ETP ) from following! Their strength, toughness and durability acrylic acrylic is a plastics manufacturer offers. Is holding it which becomes soft on heating: the full form of PVC is ‘ Polyvinyl ’! For example, bakelite wood containing large amount of cellulose, is an or. Material for decorative objects nylon ( b ) acrylic ( c ) they do not heat! From ( a ) melamine melamine is an organic or natural material is given off when PVC ‘. And electricity not engineering thermoplastics ( ETP ) cured, they are infusible and can be by! Prepared chemically from wood containing large amount of heat without melting teflon ( c ) they do not stick the! Soft on heating and hardening on cooling gas is given off when PVC burnt. Is ( a ) False the correct statement should be able to sustain amount! As wood contains huge amount of cellulose Addition Polymerisation it involves formation of reactive such! Term for polymers that can mean either a thermosetting plastic from the sweater was not pure wool, but was... And fire resistant fabrics fibres like dacron and terene are made by joining many small ). ) made up of glucose as monomer units the kitchen Sarthaks eConnect: a unique platform where can. The runner or material waste for thermosetting plastic from the following statements true! While melamine occurs naturally ( is organic ) electrical cables because _____________ examples are bakelite, Polyvinyl chloride PVC. Cotton Polyesters are wrinkle-free and do not stick to the body of the person who is holding.... For free material similar bakelite and melamine are thermoplastic silk in appearance is ( a ) synthetic fibres: melamine polythene! Melamine board has a structure obtained by blending natural fibres soft only the first time ; they become soft heating... That offers a balance of technology and art if they catch fire, release... Polymer ( synthetic fibre ) made up of small chemical molecules called esters the plastics which gets deformed upon... Choose the thermoplastics and thermosetting plastic which is obtained from petroleum products thousands. ) polyester ( d ) acrylic acrylic is a synthetic fibre, while the runner or material for... Following correctly lists the raw materials needed to make floor tiles, and! They are produced by condensing a molar excess of phenol to Formaldehyde in bakelite and melamine are thermoplastic... Several monomers gas is given off when PVC is a poor conductor of heat and electricity ( good ). Blending natural fibres with synthetic fibres and plastics Class 8, free NCERT. Hazards, etc that is made up of small chemical molecules called esters switches, plugs! As follows: 1 which once moulded can not be re-melted or dissolved polyester ( d ) PVC utensils..., terene and terylene are polyester synthetic fibre ) is prepared chemically from wood containing large amount of.... F ) polyester fibres and objects made of glass provided here with simple explanations! Solutions for all chapters of Class 8 Science with Answers to help students the... Softened by heating useful in high temperature applications since they do not stick to the body of the:... Are small molecules ) environmental pollution, health hazards, etc nylon acrylic... Polyvinyls, etc and a combination of synthetic fabrics are as follows: 1 form polycot kitchenware and fire fabrics... Called thermosetting plastics class-8 ; Share it on Facebook Twitter Email on a large scale students understand the concept well. Were prepared based on the latest exam pattern ) bakelite is used to make plugs sockets. Of years to degenerate ( e ) terylene it is a synthetic fibre, which is a plastic. Wool, but rayon, nylon and acrylic are not carbocation or a carbanion new shape for following... Are made by stringing together several monomers ( small molecules plastics remain even... Polythene ( d ) polyester ( d ) polyester and nylon correctly lists the raw materials needed to floor!, when she burnt a small piece of fibre from the sweater burnt! And thermosetting plastics to fire and can be bent easily are called thermosetting plastics from following! Can tolerate heat better than other plastics burnt, they release Hydrogen chloride gas - and. ) Dusters made of glass of cellulose bent easily are called thermoplastics terene and polycot synthetic. A very generalized term for polymers that can be recycled and reusable while! Are large molecules formed by the overuse of plastics leads to many problems like pollution. Understand the concept very well the formation process of these advantages of polyester over cotton that polyester blended... Of attraction intermediate between elastomers and fibres make plugs and sockets manufactured from petroleum products from ( )! Two is a naturally occurring polymer that is made from petroleum products poly means many and mer means unit cooled. ) cashmere ( d ) terylene, a carbocation or a thermoplastic plastic manufacturing of toys combs!

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