Question
Chemistry Question on Polymers
Thermoplastics become hard on heating and soft on cooling. Thermoplastics are cross-linked polymers which are soluble in many organic solvents.
A
If both assertion and reason are true and reason is the correct explanation of assertion
B
If both assertion and reason are true but reason is not the correct explanation of assertion
C
If assertion is true but reason is false
D
If both assertion and reason are false
Answer
If both assertion and reason are false
Explanation
Solution
In thermoplastics, the polymer chains are held together by weak intermolecuiar forces of attraction. The applied heat and pressure can easily overcome the weak forces of attraction which hold the chains and the polymer becomes soft and flexible. On cooling, they become hard and rigid.