Which of the following is not true?
In vulcanisation, the rubber becomes harder and stronger
Natural rubber has 'trans' configuration at every double bond
Buna-S is a copolymer of butene and styrene
Natural rubber is 1, 4-polymer of isoprene
Which of the following is not a biodegradable polymer?
Glyptol
Polyhydroxy butyrate-CO-β-hyrdoxy valerate
PHBV
Nylon 2-nylon-6
Formation of terylene is an example of:
condensation polymerisation
addition polymerisation
esterification
saponification
Which of the following is a condensation polymer?
[-NH-CO(CH2)5-]n
Rubber
Polyvinyl chloride
Polyethylene
The monomer used in novolac, a polymer used in paints
melamine and formaldehyde
phenol and formaldehyde
butadiene and acrylo nitrile
butadiene and styrene
B.
phenol and formaldehyde
Novolacs are phenol formaldehyde resills with formaldehyde to phenol molar ratio of less than one. The polymensation is brought to completion using acid catalysis such as oxalic acid, hydrochloric acid or sulphonate.