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--- everplast:plastic_materials:pu [2019/09/19 08:54] – created emma_hsu
+++ everplast:plastic_materials:pu [2019/09/19 08:58] (current) – emma_hsu
@@ Line 17: / Line 17: @@
 Starting in the early 1980s, water-blown microcellular flexible foams were used to mold gaskets for automotive panels and air-filter seals, replacing PVC polymers. Polyurethane foams have gained popularity in the automotive realm, and are now used in high-temperature oil-filter applications.
-Polyurethane foam (including foam rubber) is sometimes made using small amounts of blowing agents to give less dense foam, better cushioning/energy absorption or thermal insulation. In the early 1990s, because of their impact on ozone depletion, the Montreal Protocol restricted the use of many chlorine-containing blowing agents, such as trichlorofluoromethane (CFC-11). By the late 1990s, blowing agents such as carbon dioxide, pentane, 1,1,1,2-tetrafluoroethane (HFC-134a) and 1,1,1,3,3-pentafluoropropane (HFC-245fa) were widely used in North America and the EU, although chlorinated blowing agents remained in use in many developing countries. [5] 1,1-Dichloro-1-fluoroethane (HCFC-141b) was introduced in early 2000s as an alternate blowing agent in developing nations.[citation needed]
+Polyurethane foam (including foam rubber) is sometimes made using small amounts of blowing agents to give less dense foam, better cushioning/energy absorption or thermal insulation. In the early 1990s, because of their impact on ozone depletion, the Montreal Protocol restricted the use of many chlorine-containing blowing agents, such as trichlorofluoromethane (CFC-11). By the late 1990s, blowing agents such as carbon dioxide, pentane, 1,1,1,2-tetrafluoroethane (HFC-134a) and 1,1,1,3,3-pentafluoropropane (HFC-245fa) were widely used in North America and the EU, although chlorinated blowing agents remained in use in many developing countries. 1,1-Dichloro-1-fluoroethane (HCFC-141b) was introduced in early 2000s as an alternate blowing agent in developing nations.[citation needed]
 Polyurethane products often are simply called "urethanes", but should not be confused with ethyl carbamate, which is also called urethane. Polyurethanes neither contain nor are produced from ethyl carbamate.
-Non-isocyanate based polyurethanes (NIPUs) have been developed to mitigate health and environmental concerns associated with the use of isocyanates to synthesize polyurethanes.[6][7][8][9][10][11]
+Non-isocyanate based polyurethanes (NIPUs) have been developed to mitigate health and environmental concerns associated with the use of isocyanates to synthesize polyurethanes.
 ===== Reference URL =====
-  * https://en.wikipedia.org/wiki/Polyethylene
+  * https://en.wikipedia.org/wiki/Polyurethane