They are derived, synthetic materials from the oil, achieved by polymerization. Its main features are its elasticity and flexibility, as well as let you give forms and be molded easily. The big disadvantages are the fact of having to be handled within certain temperature ranges because they are very combustible and generate toxic fumes, that do not easily degrade after used. It is currently a major source of environmental pollution. In soil science, kind of soil that stops molding easily. Non-permeable. Clay soils. Waterproof.
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