(those who will answer i will mark as brainliest and give 5 thanks) 2. Write the full form of: PET and PVC. 3. Write the differences between the following giving two examples each. a) Biodegradable materials and nonbiodegradable materials. b) Thermoplastics and thermosetting plastics c) Natural and synthetic fibres. 4. Mention the advantages and disadvantages of synthetic fibres over natural fibres. C) Design an activity to show that plastics are bad conductors of electricity. Draw a neat and well labelled figure to explain.
Answers
Answer:
The seven types of plastic include: Polyethylene Terephthalate (PETE or PET) High-Density Polyethylene (HDPE) Polyvinyl Chloride (PVC)
Biodegradable substances are those which decompose naturally in the environment naturally and are considered beneficial for the environment. The natural agents involved in the degradation are air, water, microorganisms, sunlight, soil, etc. Non-biodegradable substances are those wastes which do not decompose naturally in the environment, causes pollution and are also harmful to the living being.
Examples of biodegradable substances are dead plants and animals, their waste, fruits, vegetables, flower, paper, etc., while non-biodegradable substances include chemicals, paints, plastic, rubber, toxic, plastic, metals, etc.
The rate of decomposition of biodegradable substances is slow, which completes within few days or months, whereas the non-biodegradable items either do not decompose and maintain their originality or their decomposition is so slow that it may take thousands of years.
Biodegradable substances after degradation can be used to produce biogas, manure, fertilizers, compost and thus they are profitable to the environment even after degradation. But in non-biodegradable substances the degradation rate is slow, and the separation and recycling are not easy, even expensive too and is not beneficial to the environment.
The primary difference between the two is that Thermoset is a material that strengthens when heated, but cannot be remolded or heated after the initial forming, while thermoplastics can be reheated, remolded, and cooled as necessary without causing any chemical changes.
Advantages
Strong
Synthetic fibres are strong so they can take up heavy things easily.
Retain their original shape
Synthetic fibres retain their original shape so it's easy to wash and wear.
Elastic
Can easily be stretched out.
Soft
Synthetic fibres are generally soft so they are used in clothing materials.
Colour
Varieties of colours are available as they are manufactured.
Cost
Clothes made by synthetic fibres are generally cheaper than those made by natural fibres.
Disadvantages
Does not absorb moistures
Synthetic fibres do not absorb sweat, trapping heat in our body.
Rough feel
Synthetic fibres may give rough feel, making it unsuitable for pyjamas, underwear, etc.
Advantages and Disadvantages of Natural Fibre
Advantages
Comfortable
Clothes made by natural fibres are more comfortable than those made by synthetic fibres.
Environment
Producing materials from natural fibres are less harmful to our environment.
Fire resistant
Natural fibres are resistant to fire but polymer based fibres will melt.
Disadvantages
Expensive
Materials produced by natural fibres are generally expensive as synthetic fibres can be made easily by manufacturing.
Shrink
Natural fibres might shrink due to aggressive washing.
HOPE IT HELPS. PLS MARK AS BRAINLIEST AND GIVE THANKS.