Question

The difference in the densities of low-density (LDP) and high-density polymers (HDP) is due to the fact that:

• A. LDP are highly branched structures while HDP consists of closely packed linear molecules
• B. LDP are linear chains while HDP are branched chains of polythene
• C. both LDP and HDP are unbranched linear chains with different lengths
• D. at high temperature, the density of polymer is reduced

Answer 1

The correct option is A LDP are highly branched structures while HDP consists of closely packed linear molecules

LDP obtained through the free radical addition and H-atom abstraction has highly branched structure. Due to this branching, the density of LDP becomes low.

Whereas HDP is obtained when addition polymerisation of ethene takes place in a hydrocarbon solvent in the presence of a catalyst such as triethylaluminium and titanium tetrachloride. It consists of linear molecules and has a high density due to close packing.