UV and Visible Transparent Polymers 3

[tsnigln]

I am looking for polymers that allow both UV and visible light through, but not IR. I would like it if the material would allow down to 200nm through. Is anyone aware of any such materials or where I might be able to find out more information about them?
Thanks

 

[Pud]

70% transmission @ 280nM :

http://www.topas.com/markets-optical

Doesn't mention IR, but maybe worth you asking the question. There's a link to Optical Brochure at bottom of above page but very slow to open, so I haven't seen it.


Cheers

Harry

 

[tom1953]

I was able to download the optical brochure, and I've attached a copy of the light transmission chart from that brochure.
This seems to be a hard plastic material. If you're looking for softer materials, there are clear urethanes that may be worth looking at. My company makes a clear millable polyurethane rubber (

http://www.tse-industries.com/Millathane97.asp)

which is moderately soft (50-80 Shore A). We haven't done light transmission testing, so I can't speculate on whether it would screen IR but allow visible and UV.

Hope this helps.


Tom Jablonowski, TSE Industries, Inc.
www.tse-industries.com

 

[Pud]

tom1953, please refresh your memory as to the posting policies at bottom of this page. Pretty well unchanged since 2005...

btw, why mention PU when there is no optical data available? The op specifically stated what he wanted as the most important criteria!

H

 

[tom1953]

Sorry for my apparent indiscretion, but I wanted to point out a polymer that a customer had recently done some light transmission testing on, and gotten some good results, and thought I'd mention these types of products in case the original inquirer wanted another option to consider.

For future reference, can I assume if someone else made the product, it'd be ok to mention it?

Mea culpa again,
tom

 

[Pud]

Just downloaded the transmittance graph - v. sharp cut-off - zero @ 200nM.

No go I guess...

Cheers


Harry

 

[Demon3]

Just wanted to add that the most pragmatic approach may be to get something like COC or other material with good optical transparency and add a dye or pigment to block the IR instead of hoping to get lucky and find a polymer that happens to have both properties "built-in".


Chris DeArmitt

 

[Pud]

When I suggest a material, it is usually the case that there is more than one manufacturer, so I usually name a couple.

In the case of Topas, there is only one. I think the site controllers take a dim view of self-promotion which is the main point of my post.

btw - we use PU (injection moulding), and did check where you are - too far away from UK!

Cheers

Harry

 

[patprimmer]

Further to Demon3's post, PMMA with an R filtering pigment will do the job. You need to talk to whatever Ciba call themselves these days (Clariant?) to source the data on the IR filter.

Regards
Pat
See FAQ731-376 for tips on use of eng-tips by professional engineers for professional engineers

 

[IRstuff]

Regardless of whether you can find a polymer that could transmit UV, it's another matter for it to survive that UV exposure for long.

TTFN

FAQ731-376

 

[patprimmer]

PMMA transmits UV and as it does not absorb any of it, there is no energy drawn form it to degrade the polymer.

PMMA is virtually unaffected by UV and transmits virtually all visible and UV light.

It transmits virtually no light at below 300 nanometres, raising rapidly t over 9% transmission between about 320 and 390 nano hen stays at that level to about 900 nano where it dips and climbs a bit to around 1100 nano then it drops sharply at about 1150 then see saws abut 40 to 80% to about 1600 nano then drops to almost nothing and see saws between 10 and 50% to 2200 nano then drops to opaque by 2300 nano.

Regards
Pat
See FAQ731-376 for tips on use of eng-tips by professional engineers for professional engineers

 

[Pud]

Hi Pat,

Op requires down to 200nM - PMMA? "no light below 300nM"?

Some bells ring regarding TPX (polymethylpentene) but I cannot find any relevant data on it...

Demon3 - your turn

Where's the op? Where am I?

Cheers

Harry

ps Pat: your PMMA graph would be useful if you could pm it?

 

[patprimmer]

I missed the 200 nano bit.

Back when, I sold quite a lot of TPX for ICI and I still have a small library full of data.

I actually sold 120 tonnes a year of it. They bought it at A$5000 per tonne FIS and sold at A$10,000 direct delivery from wharf. Some one made a lot of money from that effort. My reward was to be retrenched.



Regards
Pat
See FAQ731-376 for tips on use of eng-tips by professional engineers for professional engineers

 

[Demon3]

Some "Demonic" comments.

BASF is trying to buy Ciba so, in answer to what they are now called, I guess it's still Ciba for now.

TPX is one of those illusive polymers you hear about but usually never meet anyone who's seen any so kudos to Pat for that. I'd love to hear more about your experiences with it. It's famous for having the lowest density of all plastics (or is it polyolefins?) and for taking ages to post crystallise so you need to wait before using it.

In regard to this thread I would imagine poly(4-methyl-pentene) would have the same poor UV stability as PP as they both have tertiary carbons.


Chris DeArmitt

 

[patprimmer]

It can basically be thought of as a high temperature transparent PP homo polymer.

SG 0.81 The lowest of any thermoplastic
Clarity, at least as good as PC
Physical properties, very similar to PP
Thermal properties, a bit better than PC
Chemical properties, very similar to PP
UV resistance, very similar to PP
Mould shrinkage an warpage, even higher than PP.

The application was to end microwave oven cookware.

PC was specified and had a severe ESC problem.

I walked in, had a look, had a think and said try this. It worked, I got the order. To easy. Only kudos is I knew the comparative properties, so I knew it should work if it did not warp.

Price at the time, A$ 10.00 vs PC at A$ 7.00 at SG 0.8 vs 1.2

Regards
Pat
See FAQ731-376 for tips on use of eng-tips by professional engineers for professional engineers

 

[Demon3]

Thanks Pat!

Especially interesting to hear the application. Not many people would think to try that polymer. I see from the prices and densities that the poly(4-methyl pentene) was on a price parity with PC at the time. Not too bad.


Chris DeArmitt

 

[Demon3]

Did some checking on TPX and it's definitely an interesting, useful material. Also ran across its UV-VIS spectrum...

http://www.mitsuichemicals.com/tpx_cha.htm

Chris DeArmitt

 

[Pud]

Good info Chris - I thought TPX was one of the better ones at UV but not as given, down to 200nM. Quartz seems pretty good though!!

I wonder how thick the sample was for that graph? Maybe better the thinner it is?

H

 

[patprimmer]

Last I heard Mitsui's capacity was sold out and it was about 6 to 8 times the current price of PC, so that application would not fly now.



Regards
Pat
See FAQ731-376 for tips on use of eng-tips by professional engineers for professional engineers

 

[Pud]

Pat,

Shouldn't you be asleep now?

H