, , . . . – , , . . , , . , - . ( ) ( ) ( ( - ), ). , . Melt-blown polymer fibrous materials are extensively applied in filtration systems and possess high filtration efficiency at low pressure drop. The ability of filters to catch dust particles depends on the electret properties of the polymer material. In the present study electret properties of polypropylene and polyethyleneterephtalate films and fibers are investigated by means of thermostimulated and isothermal relaxation of a surface potential and differential scanning calorimetry. Influence of the temperature gradient in dielectrics on the interpretation of the experimental data is examined in detail. 1 , ( ( . 290 ), ); . - ... , , - - , . . ( 50 µ ), . , ( : , ( ) – 800 µ , : .1, 2, 1200 µ ; 15 µ ). - , . . , - , . - . 40 35 40 ?=0,025 K/c 35 25 20 20 15 15 10 10 5 5 0 0 310 ? =0,06 7 K/c 30 25 290 ?=0,05 K/c , , ?=0,05 K/c ?=0,067 ?=0,034 30 330 350 370 290 390 34 0 390 440 . 2. . 1. 1,2 1,2 . 2 0,6 3 1 0,4 3 0,2 0,2 4 340 4 0,0 0,0 290 2 0,8 1 0,6 , 1,0 , . 1,0 0,4 390 30 0 440 350 400 4 50 . 4. . 3. : : – – – – 50 0 , , 1 2 3 4 49 0 , , 0,8 , =0,050 ; , =0,025 ; , =0,038 , =0,019 – – - 1 2 3 4 ; 291 – – – – , =0,050 ; T, =0,025 ; , =0,038 , =0,019 ; , . 1,5 ). - , ( ( , ) - , ). ). ( ( . 3, 4) ( , . 1, 2, 3, 4. - 1 ( ) W, , 0,57±0,02 107 0,54±0,02 107 340–350 (330-340 ) 0,9±0,03 109 0,83±0,02 5 * 108 390–430 (380-390 ) -1 , 2 , W, 320–340 0,56±0,02 0,73±0,02 360–390 0,75±0,02 -1 , 5 * 107 109 10 9 W, , -1 0,73±0,02 105 109 0,76±0,02 5 * 108 0,39±0,01 3 ( ) W, , , 108 108 1010 1010 0,74±0,02 360–380 (350–370 ) 0,72±0,02 1,02±0,03 430–460 (420–440 ) -1 0,95±0,03 4 ( ) , W, 0,66±0,02 360–380 0,71±0,02 430–460 0,89±0,03 292 -1 , 8 10 108 1010 ... ( ) 1) . 2 440–443 K. - , : 320–330 , - , ; 3) , , , . ) . - , , W = 0,39 ( = 105c-1), , - , W = 0,56 ( 4 = 5*10 7 c -1 ). . - . ( : ) 1) , , , , , 3 , - . - . - 350-370 ( ; 2) 370–390 5 ). 420–440 , . 6 ( - ). 2) , ( , - , . 5) - . 443 K . 440 K , . , , . , - , . 5. - . . . 293 , 1 . ., . // . . 2005. 2 1. . 10–17. . Kravtsov A. G., Zotov S. V., Brunig H. Peculiarities of the electret state of melt-spun and melt-blown fibrous polypropylene materials // Mechanics of Composite Materials. 2000. V. 36. N. 6. P. 491–496. 4 . ., . . // : . , . . . , . 2006. . 59–68. 5 Gorokhovatsky Yu., Temnov D., Marat-Mendes J. N., Dias C. J. M., Das-Gupta D. K. On the nature of thermally stimulated discharge current spectra in polyethylene terephtalate // Journal of applied physics. 1998. V. 83. N 10. P. 5337–5341. 6 . 3 294