MECHANISM OF THE ACTION OF VISCOSITY-MODIFYING ADDITIVES

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP80-00809A000700240127-3
• Release Decision: RIPPUB
• Original Classification: U
• Document Page Count: 2
• Document Creation Date: December 22, 2016
• Document Release Date: July 11, 2011
• Sequence Number: 127
• Publication Date: November 18, 1955
• Content Type: REPORT

Sanitized Copy Approved for Release 2011/07/12 : CIA-RDP80-00809A000700240127-3
STAT
Sanitized Copy Approved for Release 2011/07/12 : CIA-RDP80-00809A000700240127-3
 Sanitized Copy Approved for Release 2011/07/12 : CIA-RDP80-00809A000700240127-3
Neftyanoye Khozvavatvo, Vol 32, No 2; No 3
Moscow, Feb; Mar 54
The thickening action of polymers (polyisobutenes, vinipols (polyviny)l],
voltols, polymethacrylates, and polyalkylstyrenes) depends on the structural
characteristics of their solutions. Most frequently used are polyisobutenes
with molecular weights of 15,000-25,000, which allegedly improve the viscosity-
temperature characteristics of low-viscosity oils to a greater degree than those
of high-viscosity oils. For an accurate estimate of the behavior of oils of
different viscosities, the ratio V50/V100 should be employed, because the index
of viscosity is devoid of physical significance and cannot be used for this
purpose. (V50/V1G0 is the ratio of the kinematic viscosity in centistokes at
50?C to the kinematic viscosity at 100?C in the same units.)
Thickening with polyisobutene does not improve the viscosity-temperature
characteristics of any oil irrespective of its original viscosity; it may even
make these characteristics worse when a large quantity of polyisobutene has been
added. The lower the viscosity of the initial oil at 100?C, the better are its
viscosity-temperature characteristics. By using an initial oil which has the
lowest possible viscosity (less than 4 centistokes at 100?C), and which further-
more has the most favorable V-0/V100 ratio, one may obtain an oil which has
good properties. The thickening effect of voltols and vinipols with a molecu-
lar weight of about 9,000 has also been investigated. It appears that all re-
lationships which have been established for the thickening action of poly-
isobutene are also valid in thickening with voltols and vinipols.
Contrary to statements made in the literature, the index V50/V100 charac-
terizes changes of the viscosity depending on the temperature not only in the
range 50-100 C, but also at temperatures below zero. When this index is low,
and the viscosity is also low, the oil has desirable viscosity-temperature
characteristics at temperatures below zero.
In view of the fact that the ratio v/VO (viscosity of the thickened oil to
the viscosity of the initial oil) in oil thickened with the same quantity of
polymer remains constant within a wide range of temperatures and does not de-
pend on the viscosity of the initial oil, one may conclude that the structural
state of the polymers in solution does not undergo any changes within an ex-
tensive temperature range covering both positive and negative temperatures.
The polymers exhibit the same viscosity-temperature dependence as the oils in
which they are dissolved. During the process of solution the molecules of poly-
mers tend to preserve (or to assume) their ordinary, unstretched state: they
remain unstretched and wound up into globules in solution. The process of so-
lution does not differ from that taking place when two oils are blended. The
polymers change their viscosity with the temperature in exactly the same manner
as the oils. Consequently, the viscosity-temperature characteristics of the
thickened oil must be the same as those of the initial oil which has not been
thickened, although the thickened oil has a higher viscosity.
Sanitized Copy Approved for Release 2011/07/12 : CIA-RDP80-00809A000700240127-3