Technological Characteristics of SKU-8TB Based on the Xylitane Polyether

Abzalova D.A., Rizaeva D.S , Koblanova  O.N., Abramova G.I.

International Kazakh-Turkish University named after H.A. Yassavi

 Shymkent Institute  

         Technological properties of rubber produced by different vulcanization systems (hydrogen peroxide, dimension hydrogen peroxide) were tested to characterize SKU-8TB raw rubber; its resistance to the aggressive conditions was also studied (laboratory samples).

The following properties were used to characterize raw rubber samples SKU-8TB based on the xylitane polyether:

1.     solubility in the ethyl acetate (State Norms 8981-93)

2.     glass casting temperature  (State Norms 12254-86)

3.     viscosity according to Muni (State Norms 10722-94)

SKU-8TB different raw rubber samples technological properties were studied. The main part of the raw rubber samples were completely dissolved in the ethyl acetate, this testifies to the fact that it is of linear structure and there are no cross links.  Some dissoluble polymer samples were obtained, and this may be explained by the fact that the ratio of some starting components has been changed. SKU-8TB raw rubber glass casting temperature is in the limits of -40/-430 C. Comparing SKU-8TB with SKU-8PG, glass casting temperature of which is in the limits -34, 5/-35,50C, we may say, that raw rubber SKU-8TB has much more low Ts values.

         The deviations stated are explained by the fact that poly ethers with larger molecular mass were used for the synthesis of these raw rubbers. Ratio viscosity according to Muni was used for the technological evaluation of the raw rubber. It should be noted, that this ratio is in the broad limits depending on the synthesis temperature and correlation of the starting components. We may state that poly urethane SKU-8TB (viscosity limits from 20 to 150 conditional units) is easily processed in the cold rolls (1-2).

         Determination of the processing period influence on the SKU-8TB technological characteristics was fulfilled by measuring viscosity value according to Muni at different rolling periods.

         Pelt  for determining viscosity according to Muni was manufactured in the laboratory rolls of 160 x 320 mm size, friction was 1: 24/ 1, 27; the front roll rotation velocity was 23 – 27,5 revolutions per minute, the gap between the rolls was 1,0 – 0, 05 mm.

         Raw rubber was processed in the rolls, where the rolls’ temperature was 250 C; the processing period varied from 5 to 20 minutes.

         Variations of SKU-8TB viscosity according to Muni depending on the processing period at 250 C were investigated.

         The curve testifies that if the processing period is increased, viscosity according to Muni is lowered; it may be connected with the partial destruction of the polymer. It was also necessary to clarify the possibility of the SKU-8TB raw rubber processing by casting under pressure, because this method turns to be the most productive. This method is possible for using if the viscosity according to Muni ratio is higher than 70 conditional units (3-4).

         To achieve this xylitane poly ether P-6 BA (the amount is 1,5 and 10 mass parts) was added to the sample of SKU-8TB raw rubber with the starting viscosity according to Muni, equal to 113 conditional units. Data of P-6 BA additives influence on the viscosity according to Muni is given in the table 1.

 

 

 

 

 

Table 1.

Influence of xylitane poly ether P-6 BA on the technological properties of SKU-8TB raw rubber

Quantity of P-6 BA, introduced into the raw rubber, mass part

Viscosity according to Muni, conditional units

0

131

1, 0

94, 5

5, 0

76, 7

10, 0

70, 7

 

         As it is clear from the table, introduction of 5-10 mass parts of the plasticizer leads to the lowering of the viscosity according to Muni from 131 to 70 conditional units it enables us to use this method with different values of viscosity according to Muni.

         Physical – mechanical indexes of the vulcanizors, filled with the xylitane poly ether up to 10 mass part., meet the requirements of the State Norms for the raw rubber SKU-8TB.

Reference:

1.     Apukhtina N.P. Raw Rubbers of Special Assignment / Digest. Editored   by I.V. Garmonov. – M.: VINITI.-P. 85.

2.     Zuyev Yu. Strength and Destruction of Elastic Materials. – M.: Chemistry, 1994.

3.     Korotkina D.Sh., Livshits K.S. and others. Synthesis and Properties of Non-Crystallized Urethane Raw Rubber. –M.: VNIISK, 1970. –  P. 45.

4.     Kusakov V.G. Oil Products Physical and Chemical Characteristics Methods of Analysis. – M., 1966.