n-Pentane/Iso-Pentane

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n-Pentane/Iso-PentanePowerpoint
How Polyurethane Market Has Faced the Zero ODP
(Ozone Depletion Target)
Marcello Migliorini
(Te.M.Co. s.r.l., Italy)
1) INTRODUCTION (slide N°1)
The first polyurethane blowing agent was the CO2 generated by the reaction of water with the isocyanate. It was simple and economic.
In the early 60' the Freon 11 appeared and it wa s immediately adopted by the industry as it was giving very good improvements on the polyurethane properties: Very good thermal insulation (largely better than CO2), very good solubility in the polyols (ethers and esters), low solvent effect on PU foams, an acceptable low boiling point (about 24℃) and lower cost than isocyanate (so better than water!). The product was also excellent to develop integral skin foams.
However since the 80s' the European polyurethane industry has faced the necessity of reducing the ozone depletion power of the emissions coming from the polyurethane production/use.. (slide N° 2)
The phase out of CFC and HCFC
·Market was committed in reducing the ODS
·CFC 11 has been banned in Europe since early 90'
·HCFC141 b has been banned already in most applications. It will be fully banned in 2004
·Customers and suppliers have developed several and different solutions
The largely used blowing agent F.11 was banned, and chemists struggled to find some workable solutions which could allow to replace F.11 with some other substance able to perform equally.
The performance of all the proposed alternatives were not so good as F11, and the economics were quite more severe. The HCFC 141b was, finally, the chosen alternative, it was more expensive, it has more solvent power, higher thermal conductivity and some solubility limitations, but it was the best possible technical solution and, very important, it has an ODP (Ozone Depletion Power) ten times lower than F 11. In order to face the various inconveniences the formulations were changed using some more water, b ·上一篇：本标准等效采用ISO
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