High temperatures cause the granules to burst. Sources of starch are corn, wheat, sorghum, arrowroot, cassava and sago. More than half of the starch used annually is used in cardboard production, also used as a food thickener, paste, laundry. B. Latexes Latex is a complex mixture of organic compounds which form an emulsion in water and are produced in cells called laticifers, found mostly in dicots. May be byproducts that plants secrete into laticifers as waste.
Opium poppies produce latex but it is inelastic.
Charles Goodyear discovered vulcanization in 1839, add sulfur which cross-links isoprene chain and improves elasticity. Natural rubber is still used to a large extent, even in tires, since it is more resilient than synthetic rubbers. Another possible source of natural rubber is guayule - Parthenium argentatum , plant native to Chihuahuan Desert. Plants cannot be harvested until 7 years of age. Latex can be obtained from other New World plants but primary source has always been Hevea brasilensis .