The structural regularity of the polymers is often due to :
MH SET - 2019, SET Exam - 2019,
Answer: D
Structural regularity is often due to both optical and geometrical isomerism.
Regularity in a polymer chain comes from repeating the same spatial arrangement unit after unit. For vinyl polymers this is tacticity: the configuration of the stereocentres along the chain (isotactic, syndiotactic or atactic), which is a matter of optical (stereo) isomerism. For diene polymers it is the cis or trans geometry of the double bonds in the backbone, as in natural rubber (cis-polyisoprene) and gutta-percha (trans), which is geometrical isomerism.
Both kinds of stereoregularity allow chains to pack and crystallise, so neither option alone is complete. Racemization destroys regularity rather than creating it.
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