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Re: Real Physics Question

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Sergio <invalid@invalid.com> wrote:
> On 11/29/2018 10:35 AM, Sergio wrote:
>> I have some plastic scintillation material, EJ 200 perhaps,
>> can I reshape it by softening it in water? (to keep it from air)
>> 
>> I think it flows about 140 degrees F ??  not sure
>> 
>> polyvinyltoluene
>> 
> 
> In  the  scintillator,  glass  transition  determined  from  the  heat
> ing  curve, occurs  in  temperature  354  K  while in  pure
> polyvinyltoluene  in    364 K.  T g values determined  using  DSC  are
> more  similar  to  each  other  than  results  obtained  from  PALS
> analysis.
> 
> Generally  it  is  assumed  that  the  softening  point  of  amorphous
> polymers  is  20  K below   the   glass   transition   point [103]
> .
> Therefore,softening  temperature of   J-PET scinillator  is  at
> 334 K (61 ºC). The value of softening point of commercial scintillators
> produced by Saint Gobain, which are also based on polyvinyltoluene is
> 343 K (70 ºC) [12]
> .
> Discrepancy  between  both  values  is  relatively large, but the
> method  of determination  of softening  point used by  Saint  Gobain  is
>  not  given,  so  they  cannot  be  compared  with  the high  precision.
>  Softening  point  can be interpreted  as  the  maximal  temperature  in
>  which scintillator  can  be  used.
> However
> ,
> PALSanalysis  indicates  that  changes  in  the  J-PET scintillator
> structure  start  to  occur  in  much  lower  temperature  region
> includingalso  room temperature in which scintillators are being used.
> 
> 
> *********  => SO softens about 160 F (-ish) <=
> 
> Glass is a very good and cheap material for the forms
> to bulk polymerization  of  polystyrene  and  polyvinyltoluene  because
> polymer  does  not  adhere  to the surface of  form.
> 
> 
> **********   => SO, I can use my fish tank! <=
> 

I recall that it depends on whether the PVT is cross-linked (100C) or not
(75C). 

-- 
Odd Bodkin — Maker of fine toys, tools, tables

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Real Physics Question Sergio <invalid@invalid.com> - 2018-11-29 10:35 -0600
  Re: Real Physics Question Sergio <invalid@invalid.com> - 2018-11-29 12:59 -0600
    Re: Real Physics Question Odd Bodkin <bodkinodd@gmail.com> - 2018-11-29 19:51 +0000
  Re: Real Physics Question benj <benj.fake@gmail.com> - 2018-11-29 16:58 -0500

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