SYNTHETIC MATERIALS
Introduction – polymers – polymerization – types of polymers – uses – plastics – types of plastics uses – recycling of plastics – cement – manufacture of cement – setting and curing of cement – glass preparation – properties of glass – types of glass and uses – ceramics – porcelain – preparation and uses.
REVIEW
You have studied in your previous classes, about elements, compounds and how the compounds are formed. Let us recall some of them.
· Compounds contain elements, combined together in definite proportions.
· The type of chemical change in which two or more elements combine together to form a compound is called chemical combination.
· Simple compounds form compounds of higher molecular mass through chemical reactions.
· Glucose, starh, cellulose and proteins are some of the examples of naturally occurring compounds.
· Water, ammonia, carbondioxide, methane, ethane and benzene are some of the examples of simple molecules.
· Silica, limestone, washing soda, clay are some of the useful raw materials available in nature.
INTRODUCTION
From ancient times, man has been using many naturally available substances for various purposes. Cotton, silk and jute are some of the materials used to prepare fibres and clothes. Shikakai is used for cleaning. There is a long list of products like gum, resin, dyes, wood and many more which are very useful to us. In ancient days all needs of human beings were fulfilled by naturally available substances. Catering to the needs has become difficult due to increase in population, limited availability of natural materials and long duration required for their production. Hence there is a great demand for Alternatives to natural materials. Materials not available in nature but produced by using naturally available raw materials, are called synthetic materials. Nowadays we come across many synthetic materials such as plastics. Cement, glass, fibres, ceramics.
Activity
Introduction – polymers – polymerization – types of polymers – uses – plastics – types of plastics uses – recycling of plastics – cement – manufacture of cement – setting and curing of cement – glass preparation – properties of glass – types of glass and uses – ceramics – porcelain – preparation and uses.
REVIEW
You have studied in your previous classes, about elements, compounds and how the compounds are formed. Let us recall some of them.
· Compounds contain elements, combined together in definite proportions.
· The type of chemical change in which two or more elements combine together to form a compound is called chemical combination.
· Simple compounds form compounds of higher molecular mass through chemical reactions.
· Glucose, starh, cellulose and proteins are some of the examples of naturally occurring compounds.
· Water, ammonia, carbondioxide, methane, ethane and benzene are some of the examples of simple molecules.
· Silica, limestone, washing soda, clay are some of the useful raw materials available in nature.
INTRODUCTION
From ancient times, man has been using many naturally available substances for various purposes. Cotton, silk and jute are some of the materials used to prepare fibres and clothes. Shikakai is used for cleaning. There is a long list of products like gum, resin, dyes, wood and many more which are very useful to us. In ancient days all needs of human beings were fulfilled by naturally available substances. Catering to the needs has become difficult due to increase in population, limited availability of natural materials and long duration required for their production. Hence there is a great demand for Alternatives to natural materials. Materials not available in nature but produced by using naturally available raw materials, are called synthetic materials. Nowadays we come across many synthetic materials such as plastics. Cement, glass, fibres, ceramics.
POLYMERS
Polythene, nylon and terylene are some of the materials that are commonly used in our daily life. These synthetic materials are called polymers. (The words ‘poly’ means many are ‘meros’ means parts) they are prepared by using some naturally available materials. Do you know how polythene is made ? A number of ethane molecules chemically combine together to form a giant molecule.
Polythene, nylon and terylene are some of the materials that are commonly used in our daily life. These synthetic materials are called polymers. (The words ‘poly’ means many are ‘meros’ means parts) they are prepared by using some naturally available materials. Do you know how polythene is made ? A number of ethane molecules chemically combine together to form a giant molecule.
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| Polythene |
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| Nylon |
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| Terylene |
Make a list of natural and synthetic materials that you come across in your daily life.
Compounds which are formed by the union of a very large number of molecules of a simple compound or simple compounds united in a repetitious manner are called polymers.
The simple compounds which build up the polymer molecule are called monomers.
Polymerisation : the process in which two or more molecules of a simple compound unite together to form a new compound is called polymerization.
Types of polymers :
All polymers are not synthetic; some are found in nature. Proteins, carbohydrates, fats and nucleic acids are some of the natural polymers. They are the essential components of our fodd. The polymers which are available in nature are natural polymers. Some of the commonly used polymers such as nylon, terylene are not found in nature; they are synthesized. They are synthetic polymers.
Synthetic polymers are classified into 1) addition polymers and 2) condensation polymers.
Addition polymerization is a process in which several molecules join together to form a giant molecule during the reaction. Theere is no elimination of molecules. They are prepared from unsaturated monomers. Ex. Polythene and polyvinyl chloride (pvc).
Polymers obtained by the condensation reaction between monomers are called condensation polymers. The polymerization in which several monomers form a polymer with the elimination of some simple molecules during the reaction is called condensation polymerization.
The condensation involves elimination of molecules like water, methanol etc. Leading to linking of polymers. Nylon-66 and terylene are condensation polymers.
Some important polymers. Their used and the monomers from which they are formed, are listed below :
Compounds which are formed by the union of a very large number of molecules of a simple compound or simple compounds united in a repetitious manner are called polymers.
The simple compounds which build up the polymer molecule are called monomers.
Polymerisation : the process in which two or more molecules of a simple compound unite together to form a new compound is called polymerization.
Types of polymers :
All polymers are not synthetic; some are found in nature. Proteins, carbohydrates, fats and nucleic acids are some of the natural polymers. They are the essential components of our fodd. The polymers which are available in nature are natural polymers. Some of the commonly used polymers such as nylon, terylene are not found in nature; they are synthesized. They are synthetic polymers.
Synthetic polymers are classified into 1) addition polymers and 2) condensation polymers.
Addition polymerization is a process in which several molecules join together to form a giant molecule during the reaction. Theere is no elimination of molecules. They are prepared from unsaturated monomers. Ex. Polythene and polyvinyl chloride (pvc).
Polymers obtained by the condensation reaction between monomers are called condensation polymers. The polymerization in which several monomers form a polymer with the elimination of some simple molecules during the reaction is called condensation polymerization.
The condensation involves elimination of molecules like water, methanol etc. Leading to linking of polymers. Nylon-66 and terylene are condensation polymers.
Some important polymers. Their used and the monomers from which they are formed, are listed below :
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| Important Polymers and the monomers uses. |
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