Newsgroup sci.polymers 8364

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In article <01bbc149$d34e0660$0df909cb@tfmann>, Terry Mann
 writes
>The reaction of phenol with styrene to give a mixture of hindered phenols
>(used for rubber antioxidant) is catalysed by sulphuric acid.  I am looking
>for
>a good way to neutralise the acid catalyst after the reaction WITHOUT
>forming a solid
>precipitate.  Perhaps sulphuric acid is not the best catalyst?
>The material needs to be neutralised so it can be added to an anionically
>stabilised 
>latex with out coagulating it.
>
>Any ideas appreciated.
>
>Terry Mann
Can you pass it through an ion exchange column?  Or on the lab scale,
mix in some ion exchange beads and filter?
-- 
Dan Bode
ICI Paints

Are you asking about blistering during cure or during some type of
testing?
There are textbooks on paint defects which should help reduce the drain
on your brain cells.  Try your library.
In article <326E772C.1AAF@RohmHaas.com>, Kum Lai Meng
 writes
>Blistering in organic coatings is undesirable.  But how can we prevent
>it from happening?  I guess to prevent it, you have to understand the
>causes of this phenomenon first.  So, I sincerely hope some experts out
>there could enlighten me and help solve/prevent some of the blistering
>problems from occuring.
>
>To start the ball rolling, I have drained zillions of my brain cells to
>come out with a couple of possible causes to blistering.
>
>Causes
>1) Poor surface preparation (resulted in localized interfacial adhesion)
>and poor breathability of coating
>
>2) Presence of salts (esp. hygroscopic salts that are migrated to the
>surface when moist concrete dries) underneath coatings.
>
>3) Presence of water sensitive ingredients in the coating, causing the
>absorption of water into the coating and hence blisters from within the
>coating.
>
>So the above are the possible causes I thought of.  Any comments out
>there? 
>
>Waiting patiently for an answer - day and night.
>
>Rgds, Lai Meng.
-- 
Dan Bode
ICI Paints

In article <54m2li$jk8_001@FUNGUS.LLAN>, Doug White 
writes
>I've got a formula for a microwave dielectric that includes divinyl 
>benzene.  I found all the other ingredients at various chemical co.'s 
>Web sites, but struck out on this one.  The formula is over 30 years 
>old, and I suspect that divinyl benzene is called something else these 
>days.  I ran a web search and didn't come up with much.  Any 
>suggestions?
>
>Thanks!
>
>Doug White
>MIT Lincoln Laboratory
Still called divinyl benzene commonly.  Available, I believe, from Dow
Chemical.  I'll check on that when I'm back in the lab.  Used in
suspension polymerization of polystyrene beads -- controlling the degree
of crosslinking by the amount of DVB gives beads the characteristics
needed for size exclusion chromatography. 
-- 
Dan Bode
ICI Paints

I received the following reply from Dow:
Re: Dow CIG Inquirey (Forms submission) (Business Analyst , Mon 11:15)
To: 
    "wlb@virginia.edu" 
-- [ From: Business Analyst * EMC.Ver #2.5.02 ] --
SARAN is a trademark of the Dow Chemical Company for polyvinylidene
dichloride (PVDC).  This material is often either co-extruded or coated
upon
another material (such as polyethylene) for barrier packaging
applications. 
Because of its excellent water vapor and oxygen transmission rates, it
often
gets used for food contact applications.  There is nothing inherent in
the
material, however, which prevents its non-food usages.
You are correct in that one of our subsidiary companies, DowBrands, used
our
SARAN resin to make SARAN Wrap.  We are sending you additional technical
information by mail.

Doug White wrote:
> of p-tert-Butylcatechol as a stabilizer.  I have a paper on styrene
> dielectrics that recommends a mix of 100 parts Styrene monomer, 6 parts
> Divinyl benzine and 1 part Benzoyl peroxide.  My assumption is that the
> peroxide is the catalyst, but I'm not sure what the Divinyl benzine is
> doing.  It may be there to stabilize the monomer, aid in machinability
> or something else.  
Divinyl benzine is a crosslinking agent to link the indivial polystyrene 
chains. With the aid of Divinyl benzine you will get a polystyrene resin. 
Beside this the peroxid is a initiator and not a catalyst.
Peter Marquardt

On 24 Oct 1996 10:57:25 -0400, a066@Lehigh.EDU wrote:
>I am also having trouble locating
>the representative of Asahi ABS in US.
Our local Asahi rep (for Greater Boston) is Hubbard-Hall Corp.  in
Lincoln, RI.  
They may have info on reaching Asahi in PA.
______________________
'94 XLH 1200
    http:\\www.tiac.net\users\greendm

<>
Depends on the system.  In solvent borne coatings, the solvents are
formulated to have 'tail solvents' to prevent skinning over and later
blistering, allowing lower boilers to evaporate out more completely,
allowing resin to continue to flow and level for optimal costmetic.  All
such resolutions depend upon whether you are talking about water based,
solvent based, neat, air dry or oven dry.

>> I have a paper on styrene
>> dielectrics that recommends a mix of 100 parts Styrene monomer, 6 parts
>> Divinyl benzine and 1 part Benzoyl peroxide. 
>> 2) Am I likely to have much excitement when I mix this stuff together?
>> Is there a prefered way to mix the materials, like adding acid to water?
Well, its going to polymerise and there will be an exotherm and some 
shrinkage and in the worst case scenario, you'll get voids (bubbles) in your 
polystyrene. (No explosions and not much excitement. Sorry...)
If you want a small test sample, you can put the styrene monomer in a 
test-tube, add about 1 pph benzoyl peroxide and the filler and shake it till 
the benzoyl peroxide dissolves and then leave it in a 80 C water bath for a 
few hours to get the benzoyl peroxide going. Next day, you'll have your 
polystyrene. And oh.... better cap the test-tube lightly. 

RIOUBLANC Jérôme  wrote:
>You're right, I spoke about index of reflaction.
>May I ask you another help please ?
>I would like some more informations about this "Polymer Handbook" : 
>publisher or n°ISBN.
>Thank you for your mail.
I see that a separate posting has already given you the publisher and the 
price. It is a standard refernce book in many technical libraries, so 
that is why I suggested it. It is a very good reference for the polymer 
field. However, information regarding the Lorentz-Lorenz equation is 
available in other sources as well, so start with what you have and go 
from there.
John
Opinions expressed herein are my own and may not represent those of my employer.

Marquardt.Peter@t-online.de (Peter Marquardt) wrote:
>I am concerned with polyolefine components, that get in contact with water. 
>Problem is the growth of microorganisms on the surface of the materials. I do 
>not understand, how microorganisms live on such an inert material. 
>Is it due to surface roughness, so that microorganisms live on sedimented 
>stuff in the holes in the surface? Or do they get their food from the 
>polyolefine materials (the materials smell a little bit sweet)?
>
>Who can help us?
>Can anyone tell us references from literature?
>
>Peter Marquardt
Peter,
Polyolefins can indeed be a carbon source for microorganisms along with 
dirt and debris that attach themselves to the surface. For that reason, 
some latex based paints, consumer products such as shower curtains and 
the like need the protection of biocides to keep the microorganism 
population under control. Microorganisms can include bacteria, mildew and 
fungi. 

Dear Sir,
	I am an undergraduate student at Washington State University.  I
am working on a term paper for a polymers class.  The topic is non-typical
curing mechanisms for epoxies.  For instance, the teacher challenged me to
find an epoxy system that can cure at low temperatures and high pressure
(i.e. for patching a dam).  If you know any of interest please contact me
at:
Jungkd@wsunix.wsu.edu
 or
David Jungk
1000 N.E. Alfred Lane, Apt. B
Pullman, WA  99163
Thank you,
David Jungk
Dept. of MME
Washington State University

	At one time I had a laboratory experiment for an undergraduate
level polymers lab in which polymer specimens were lit on fire.  The type
of polymer could then be determined.  If anyone has a copy of this type of
experiment could you please send to:
	Jungk@wsunix.wsu.edu
or 	David Jungk
	1000 N.E. Alfred Lane, Apt. B
	Pullman, WA  99163
	Thank you
	David Jungk
	Dept. of MME
	Washington State University

Does any body have any idea where the best source of current prices
and price histories can be found for polystyrene and styrene?
Kurt Derscha

Hi.  Being new to this group I may have missed previous discussions, but I'd 
like some help with the following; the reference books I've seen haven't been 
much help (the names of relevant references would also be appreciated).
I'm trying to determine the best method for re-molding expanded polystyrene.  
Some compaction (say less than 50%) of the material would be acceptable.  The 
most likely pre-processing I envision will be washing and mechanical  sizing 
of the material.  After that I'm unclear as to:
1) will heat/pressure alone allow for remolding, and if so, at what 
conditions will bonds form?  (I'm not sure what tensile strength I'll need)
2) is some form of binder required?  Under what conditions should it be 
applied?
3) is a mold pre-prep required to give a smooth, non-porous finish?  
4) are there any companies currently doing this sort of thing?
5) is it easier to just reprocess to impregnated PS beads?
Thanks in advance for any assistance offered.  You can e-mail me direct at
cvilcsak@edpower.com

mcclellt@primenet.com (Tom McClelland) wrote:
>Sharon Kelly  wrote:
>>I'm looking for some help in selecting a material. My requirements are:
>>1. Chemical resistance to Toluene, Hydrofluoric Acid, Sulfuric Acid, and
>>Methylene Chloride.
>>2. Must be able to form or machine to close tolerances (+/- .0005 in).
>>Overall size of part is less than 2" x 1" x 1/2".
>>3. Must be able to bond reasonably well using a UV cured epoxy.
>>4. Must be a very rigid material, a metal is preferable, elastomers are
>>out of the question.
>>We are currently making this part out of aluminum or stainless steel
>>which worked well until we introduced the requirement for exposure to
>>sulfuric acid. The best metal my simple material compatability charts
>>gave me to handle the sulfuric acid is bronze. Graphite also seems to be
>>a candidate but I don't think that takes the HF acid well. Teflon is
>>great for chemical resistance but is probably not rigid enough and too
>>hard or impossible to bond to.
>>Does anyone have a suggestion?  Cost is no object.
>>Any ideas would be greatly appreciated. I'll monitor these news groups
>>or please e-mail me direct.
>>Thanks
>>Dan
>>dschlig@hotmail.com
>	I suggest that the easiest way to do this would be to coat your
>current  aluminum or stainless steel part with a thin coat of teflon
>or other polymer.   What temperature are you working at?
If cost is no object have you thought about Tantalum