In elastomers,the intermolecular forces are......

Buna-$N$ synthetic rubber is a copolymer of:

Observe the following polymers.
$I$. $PHBV$
$II$. Nylon-$2$-nylon-$6$
$III$. Glyptal
$IV$. Bakelite
Which of the above is/are biodegradable polymer$(s)$?

Which of the following is a biodegradable polymer?

Choose the correct option$(s)$ from the following:
$(1)$ Natural rubber is polyisoprene containing trans alkene units.
$(2)$ Nylon-$6$ has amide linkages.
$(3)$ Cellulose has only $\alpha-D$-glucose units that are joined by glycosidic linkages.
$(4)$ Teflon is prepared by heating tetrafluoroethene in the presence of a persulphate catalyst at high pressure.

The monomer units of nylon-$6, 6$ and nylon-$2$-nylon-$6$ are respectively: