Question

Trans-form of polyisoprene is:
A.Gutta-percha.
B.Hydrogenchloride rubber.
C.Buna-N
D.Synthetic rubber.

Answer 1

Hint: Gutta-percha is a tree belonging to the genus Palaquium in the family Sapotaceae. The name also refers to the naturally and biologically inert, rigid, electrically non-conductive, resilient, thermoplastic latex developed and produced from the sap of the tree mainly from Palaquium gutta. It is a polymer of isoprene that acts like a rubber-like elastomer.

Complete answer:
Gutta-percha, chemically, is a polyterpene which is a polymer of isoprene, or polyisoprene and to be specific trans\[-1,4-polyisoprene.\] The cis-structure of polyisoprene forms the common latex elastomer. While latex rubbers are non-crystalline or amorphous in molecular structure, gutta-percha which is the trans-isomer, crystallizes, leading to develop more rigidity in the material.
Gutta-percha latex is biologically inert, resilient, and is a good electrical insulator and does not allow current to flow through it and provides high resistance to the current. The latex has a high dielectric strength. The wood of many species is also valuable and is of high economic value.
Polyisoprene is a collective name for polymers that are produced by polymerization of isoprene. Isomer cis\[-1,4-polyisoprene\] is a major ingredient of natural rubber whereas trans\[-1,4-polyisoprene\] is a major ingredient of gutta-percha.

Hence, option A is correct.

Note:
Remember that Due to its bio-inert nature, gutta percha is suitable for developing marine cables and it does not react readily with the human skin or the body. It is used in a variety of surgical devices and during the root canal therapy.