שאלה | Natural rubber, Hevea is sticky, elastic and a mechanically weak polymer while Gutta-percha is harder and more non-elastic. Both are made of exactly the same monomer material (isoprene) and have the same chemical composition. What is the best explanation for their different properties?

Natural rubber, Hevea is sticky, elastic and a mechanically weak polymer while Gutta-percha is harder and more non-elastic. Both are made of exactly the same monomer material (isoprene) and have the same chemical composition. What is the best explanation for their different properties?

		There is a large difference in molecular weight.
		Gutta-percha i is partially crosslinked.
		The stereochemistry of Hevea is atactic while Gutta-percha is isotactic allowing for better packing and is thus partially crystalline.
		Hevea has cis-double bond geometry, and Gutta-percha has a trans-double bond geometry allowing for better packing and is thus partially crystalline.