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Subject: Re: Brake Fluid
From: (Carl Ijames)
Date: Sep 04 1996
Newsgroups: sci.chem

Syed Ali Afzal Rizvi ( wrote:
: Does anyone know the processes involved in making brake fluid...or the
: components...machinery needed...actually will be grateful for any info on
: the brake fluids. 

Well, DOT3 brake fluids are "alkylene glycols".  I analyzed some Prestone fluid
once, and it was a mixture of about two polymers and one copolymer.  The
copolymer contained 0 to about 6 CH2 units and 2 to 5 or so CH2CH2O units, plus
C3H6 (based on exact masses by ESI/FTMS).  Presumably one end group was H2C=CH-
and the other was -CH3.  The other polymers were also based on CH2CH2O repeat
groups with different saturated end groups totalling 4 to 6 C's.  The overall 
average (by eyeball) molecular weight was about 400, and the heaviest component
detected was in the neighborhood of 1000.  I imagine that most ethylene glycol
based polymers such as these and the common surfactants like Triton X-100 are
made by similar reactions, from ethylene oxide. 

Carl Ijames

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