Complete Report on Work

Obtained data can be interesting for companies developing and producing cable plasticates and other materials based on plasticized PVC to predict changes in properties of plasticates of different compositions, and to determine the storage life for these materials.

Data on a long-term ageing and the technique of accelerated ageing developed on their basis can be interesting for companies developing and producing cable plasticates (and other materials based on plasticized PVC) to predict actual service life of wires and cables at high temperatures.

Testing of the following cable plasticates was carried out:

• - commercial unfilled plasticates - for 20-27 years;
• - filled with 50, 100, 150 pbw calcium carbonate (per 100 pbw PVC) - for 13 years;
• - for ship cables with lowvolatile plasticizers (didodecyl phthalate and dioctylcebacate, tetraoctylpiromellitate) and fillers (calcium carbonate, kaolin, aerosil) - for 20 years.

The following properties of plasticates were controlled during the whole storage period:

• - tensile strength at break (ISO 1184-70, ASTM D638, GOST 11262-80);
• - elongation at break (ISO 1184-70, ASTM D638, GOST 11262-80);

• - volume resistivity at 20 and 105oC (ASTM D257, GOST 6433.2-71, GOST 5960-72).

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  2. The present report gives data on change of properties of cable plasticates for ship cables
  (based on plasticized PVC) at heat ageing at 85oС for 15 years.

Three formulations of cable plasticates based on lowvolatile plasticizers were studied. The following properties of plasticates were controlled during the whole heat ageing period:

• - tensile strength at break (ISO 1184-70, ASTM D638, GOST 11262-80);
• - elongation at break (ISO 1184-70, ASTM D638, GOST 11262-80);
• - frost resistance characterising by the brittle temperature (GOST 5960-72)
• - volume resistivity at 20 and 105oC (ASTM D257, GOST 6433.2-71, GOST 5960-72);
• - electric strength.

The pressure-volume-temperature (P-V-T) relationships along with the thermal expansion coefficients (a) and the isothermal compressibility (b) were studied experimentally for high and low molecular weight PMMA in the range of pressure 0,1 - 700 MPa and temperature 20 - 200│C. The accuracy of measurements is : │0,2│, │0,05%, │0,15% for T, P and V respectively. On the base of these data the thermodynamic functions of state are calculated: enthalpy, enthropy and internal energy. The data offered can be applied to the solution of many PMMA processing problems, specifically in the production of high precision optical parts because commonly used equations of state don't permit to predict a, b and da/dT with the high degree of accuracy in a wide range of P and T. Information about Developer: Data were obtained in V.A. Kargin Polymer Chemistry and Technology Research Institute . V.A.Kargin Institute possesses more than a 40-years experience in the field of polymer science.

Possible scope of agreement:

• Tabulated P-V-T data.
• Tabulated P-V-T data and the thermodynamic functions
• Some data on modified PMMA grades
• The complete report.