PPD is solvent in what?

Discussion in 'B&W: Film, Paper, Chemistry' started by patrickjames, Jun 10, 2008.

  1. patrickjames

    patrickjames Member

    Messages:
    743
    Joined:
    Mar 25, 2005
    Shooter:
    Multi Format
    I was wondering what P-phenylenediamine is solvent in. I just received 100g of the stuff but it is of course in a big lump so I won't be able to measure it. I would like to put it into a percent solution so I am more easily able to utilize it. PG, TEA ? Any suggestions? Does it keep well in H2O?

    Thanks

    Patrick
     
  2. Photo Engineer

    Photo Engineer Subscriber

    Messages:
    25,897
    Joined:
    Apr 19, 2005
    Location:
    Rochester, NY
    Shooter:
    Multi Format
    It keeps poorly.

    It is soluable in sulfuric acid solution with sulfite as a preservative. I could not give you an offhand suggestion as to how to do this, as it is more normal today to use substituted PPDs such as CD2, CD3, and CD4. They work much the same way and come as crystalline acid salts.

    PE
     
  3. richard ide

    richard ide Member

    Messages:
    1,227
    Joined:
    Nov 8, 2005
    Location:
    Wellington C
    Shooter:
    Multi Format
    You could try quartering it to measure smaller amount with reasonable accuracy. Powder the PPd and make a pile on a piece of paper, take something like a cake knife with a straight blade and cut through the pile, moving half away to the side, do this again at 90 degrees and you have 4 piles of 25 gm each. Repeat htis procedure again with one pile and you have 6.25 gm per pile. Again and you have 1.56 gm per pile.
    A usable substitute sometimes if you do not have a scale. Take care with toxic items.
     
  4. df cardwell

    df cardwell Subscriber

    Messages:
    3,341
    Joined:
    Jul 16, 2005
    Location:
    Dearborn,Mic
    Shooter:
    Multi Format
    Mortar and pestle does wonders.

    I collect the big and little chunks, it measures very nicely.

    Hot Water is needed, but it dissolves readily if you grind the PPD finely.
     
    Last edited by a moderator: Jun 10, 2008
  5. jim appleyard

    jim appleyard Member

    Messages:
    2,130
    Joined:
    Nov 21, 2004
    Shooter:
    Multi Format
    I broke my lumps up with the butt-end of a screwdriver and then measured out the PPD with the teaspoon method.

    Curious, which formula do you plan to make?
     
  6. Photo Engineer

    Photo Engineer Subscriber

    Messages:
    25,897
    Joined:
    Apr 19, 2005
    Location:
    Rochester, NY
    Shooter:
    Multi Format
    PPD often gets gooey or tarry. Using a mortar and pestle only turns it into a paste in this case and mashes it into the unglazed portions of the mortar and the pestle.

    It can be weighed out and then dissolved in concentrated sulfte with sulfuric acid as I said above. In fact, all color developers are measured out that way to insure that the PPD does not decompose.

    It is quite unstable in water. In fact, if you try to dissolve it in water, you get a colored solution that is a mixture of decomposition products. Adding a pinch of sulfite clears the color at the expense of adding it too late and getting low activity.

    It is the same as with metol and HQ only more so.

    PE
     
  7. jochen

    jochen Member

    Messages:
    353
    Joined:
    May 13, 2008
    Location:
    Germany
    Shooter:
    35mm
    Hello Patrick,
    be very careful when handling PPD. It is very toxic and maybe carcinogenic. Use gloves! It causes brown stains on skin, table and clothes which cannot be removed any more.
     
  8. df cardwell

    df cardwell Subscriber

    Messages:
    3,341
    Joined:
    Jul 16, 2005
    Location:
    Dearborn,Mic
    Shooter:
    Multi Format
    1. Assume everything is bad for you.
    2. Rinse mortar.
    3. Don't use mortar for food.

    It really isn't that difficult to keep dry, and use as it is needed
     
  9. Mike Wilde

    Mike Wilde Member

    Messages:
    2,933
    Joined:
    Aug 10, 2006
    Location:
    Misissauaga
    Shooter:
    Multi Format
    and store just like glycin

    I keep mine in the freezer, in a well sealed jar. Mine came as lightly purple coloured flakes, and so far they have not changed by keeping them frozen.

    and yes, it stains. I use mine in a replenished Harveys 777 developer. Combined with the silver in the seasoned solution, it either stains you up front, or after you have been out in a lit environment, and then try to wash up in some soap. The alkanine soap, combined with residual ppd and glycin lets the silver blacken on your skin quite well. Then it si just a matter of waiting for the stained skin to waer away for the stain to fade.

    The first round of this tought me that the nitrile gloves I have should be on my hands, and not hanging on the edge of the sink when using this stuff.
     
  10. patrickjames

    patrickjames Member

    Messages:
    743
    Joined:
    Mar 25, 2005
    Shooter:
    Multi Format
    How about boric acid instead of sulphuric?
     
  11. Photo Engineer

    Photo Engineer Subscriber

    Messages:
    25,897
    Joined:
    Apr 19, 2005
    Location:
    Rochester, NY
    Shooter:
    Multi Format
    The sulfate salt is more soluable than the borate salt, but it might work. The key is to have sulfite there in high enough concentration.

    I have spent most of my adult life working with PPD developers, and have handled them in all conditions. The only bottom line is keep them acidic with sulfite present.

    PE