[frameconnews] Re: Fwd: Alkaline reserve, what is it?

["Stephen Todd" <Stephen.Todd@btinternet.com>]

Strangely enough, I have downloaded his paper from
Alkaline Paper Advocate. [For those interested see
http://cool.conservation-us.org/byorg/abbey/ap/ap02/ap02-1/ap02-1
11.html ]

In this he states "The titrations also give also give a measure
of the alkaline reserve left in the paper by the deacidification
methods.."
To me this suggests that the chemical purification of high alpha
cellulose
woodpulp, leave an alkaline residue, called the reserve, and
that
subsequent calcium carbonate or other additives form the
`buffer' against
further retrograde changes in the pH of the material. I think
these can
also be `fillers' added to impart a finish to the pulp board.



-----Original Message-----
From: Abbey Publications [mailto:abbeypub@flash.net]
Sent: 17 July 1999 01:57
To: Stephen Todd
Cc: CGrzywacz@getty.edu
Subject: Re: Fwd: [frameconnews] Alkaline reserve, what is it?


Mr. Todd - When I was at the Library of Congress in 1979-80, I
used to talk
to George Kelly, one of the chemists there, because I was hungry
for
information about paper permanence, and he was doing research on
it for the
LC.  In fact, the LC specifications for its own paper and board
served as
the de facto permanence standard for this country at the time.
(Framers
still use them.)  He said one time that he had been wondering
whether to
call the calcium carbonate and magnesium compounds added during
aqueous
deacidification "alkaline buffers" (which was the usual chemical
term for a
compound that fixed the pH of something at a certain level) or
an "alkaline
reserve," and I remember when he decided that "alkaline reserve"
was going
to be his preferred term, because, if I remember correctly, it
described
more accurately what it did.  The alkaline reserve functioned
like an army
reserve, going into action when needed, rather than fixing the
pH of the
paper.  He was good at communicating with nonchemists, and I
also think he
felt this phrase would be easier to explain.

Others could have gone through a similar thought process, and
come to a
similar conclusion, but this is what I remember.


>We are discussing mountboard used in the
>storage and display of art on paper. Both
>cotton and purified woodpulp furnish. We
>are aware of the implications of buffering
>and photographs.
>
>We are not discussing papers used to make
>documents, newspapers or books etc.
>
>We are not discussing buffer solutions used
>by conservators working with materials that
>may be acidic.
>
>2. The question:
>
>Please give your definition of the difference between:
>
>Alkaline reserve and, alkaline(of course)buffer.
>
>Stephen Todd
>Moderator Frameconnews.

Ellen McCrady
7105 Geneva Dr.
Austin, TX  78723
512/929-3992; fax 929-3995




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