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    You see, these polymers are so new that not much has been made out of them yet. This attraction is so strong that while polyethylene melts at a mere 140oC, the polyketone doesn't melt until 255 oC!

    Every now and then you get an extra methyl group attached to one of the ethylene units.pslc.pslc. Most high performance polymers are difficult to make, because the chemistry has to be just right for the reactions to work.pslc.

    Keep watching this page. This makes the polyketones very strong, but the down side is that it also makes them very brittle. The bad part is that the melting temperature drops to about 220 oC, because the crystals aren't as strong.gif" />

    R' is an ethylene linkage, -CH2CH2-. But those carbonyls do a lot. This is not to be confused with a carillon, which is a musical instrument with differently pitched bells, which are often controlled with a piano-like keyboard. Shell has just put this family of polymers on the market and sells them under the name Carilon. Ethylene is on the left and carbon monoxide is on the right.pslc.ws/macrog/images/ket07. These methyl groups get in the way when the polymer chains try to pack into crystals.ws/macrog/images/ket04.ws/macrog/images/ket03. You see, carbonyl groups are very polar. We've seen high performance before..pslc. A polyketone is of course a polymer with a ketone group in the backbone chain. But that's no problem with polyketones!

This is all very nice, but really, now, what's the big deal? There are lots of high performance plastics out there. This is because oxygen is electronegative and draws electrons away from the carbon atom. But the good part is that the polymer is now a lot tougher and less brittle. The only difference is that the polyketone has those carbonyl groups in it. As soon as we find out what people are making out of polyketones we'll post something here about it!


Reference of this text is: http://www.gif" />
There was a problem with this polyketone when Shell first made it. You make carbon monoxide every time you burn wood, or a candle, or just about anything containing carbon. This comes in handy should you want to make a car part out of this stuff.

Polyketones So what's so great about polyketones? Let's find out by taking a look at them. These polar carbonyl groups are attracted to each other, and very strongly at that.pslc.gif" />


For polyketones at a glance, click here!

I would just love to tell you that many wonderful things are made of polyketones, but I can't.gif" /> It's not much different. A car part is no good if it dissolves when you spill gasoline on it.gif" />

    These polyketones have another interesting property. They won't dissolve in much of anything.pslc. What makes polyketones so special?

    This is what makes polyketones so special. Cheap monomers, and easy chemistry make polyketones rather cheap, a whole lot cheaper than other high performance plastics.ws/macrog/images/ket06. They can still pack, but not as well as before.pslc. So oxygen has a slight negative charge and the carbon has a slight positive charge. There are poly(ether sulfones), poly(phenylene sulfide), polyimides. But polyketones, which are plastics, by the way, have a lot going for them, and we figure it won't be long before a lot of stuff is made from them. Propylene reacts just like ethylene does, so we end up with a polymer that looks like this:

    Ethylene is dirt cheap; it's the monomer for polyethylene.pslc
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