Re: poly(vinyl alcohol) (was Re: Gloy is NOT PVA)

From: davidhatton@totalise.co.uk
Date: 03/27/06-04:04:10 AM Z
Message-id: <E1FNoa2-0000Bw-ER@webm10.global.net.uk>

('binary' encoding is not supported, stored as-is) Thanks Ryuji,

Exactly what I wanted to know!

David H

On Sun, 26 Mar 2006 15:25 , Ryuji Suzuki <rs@silvergrain.org> sent:

>Poly(vinyl alcohol) was first prepared by saponification of poly(vinyl
>esters) by Herrmann and Haehnel in 1924, and first published in
>scientific literature in 1927. The current method of production is
>transesterification of poly(vinyl esters) by alcohols in presence of
>alkali catalyst. This method was developed by those two and Berg in
>1932.
>
>Note that, poly(vinyl alcohol) is still a rather broad range of
>polymers that vary in terms of degree of hydrolysis and the type of
>alcohols (the ratio of 1,2-diol and 1,3-diol).
>
>Completely hydrolyzed or nearly completely hydrolyzed poly(vinyl
>alcohol) is used as adhesives for paper, paperboard, textile,
>etc. There are several common additives to these types of adhesives.
>
>Partially hydrolyzed copolymer, poly(vinyl alcohol-co-acetate) is used
>for very similar applications as well, together with vinyl
>acetate. They make excellent vinyl acetate emulsion adhesives, that
>have superior adhesion properties. This is very typical of wood glue
>products.
>
>Paper sizing is another major application of PVA. Completely
>hydrolyzed PVA provides good strength and wet resistance, compared to
>styrene-butadiene latex copolymer (which requires twice as much),
>casein, starch, etc. (often require 3x as much). Patents for inkjet
>papers often mention PVA with colloidal silica as the binder to coat
>on paper, which has such desirable properties as quick absorption of
>moisture with little spreading and dye penetration.
>
>
>From: "graeme.lyall" graeme.lyall@ntlworld.com>
>Subject: Re: Gloy is NOT PVA
>Date: Sat, 25 Mar 2006 19:51:42 +0000
>
>>
>> According to Arthur Johnson in his book "The Repair of Cloth Bindings: A
>> Manual" published by the Oak Knoll Press and The British Library in 2002
>> (page 11), PVA was developed in Germany in 1912 by a Dr Klatte, but it was
>> not in general use as an adhesive for packaging and bookbinding until the
>> middle of the 20th century.
>>
>> ----- Original Message -----
>> From: davidhatton@totalise.co.uk>
>> To: alt-photo-process-L@sask.usask.ca>
>> Sent: Saturday, March 25, 2006 6:33 PM
>> Subject: Gloy is NOT PVA
>>
>>
>> >
>> > Hi All,
>> >
>> > I know, it's an old subject but I would like a bit of information from
>> > someone in the chemistry field. But first, in my search for the elusive
>> > and
>> > almost extinct Gloy gum, I came across some interesting information. Two
>> > quotes both from different sources state that the gum (Gloy) does
>> > not contain any PVA.
>> >
>> > Does anyone out there now of a date when PVA was discovered/invented? This
>> > is directly relevant to the accuracy of this information.
>> >
>> > Can anyone help?
>> >
>> >
>> > David H
>> >
>> >
>> >
>> > ---- Message sent via Totalise Webmail - http://www.totalise.co.uk Up to
>> > 2Mb Broadband now from just £11.99 a month
>>

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Received on Mon Mar 27 04:06:38 2006