pps proceeding - Abstract Preview
pps proceeding
Symposium: G13 - Polymer foams
Oral Presentation
 
 

Conductive foams of HMS-PP with carboxyl-functionalized MWCNT

Suman Bretas Rosario Elida (1)*, Bianchin Olavo Serafin (2)

(1) Materials Engineering at Universidade Federal de Sao Carlos - São Paulo - Brazil, (2) Pirelli Pneus - SP - Brazil

Conductive foams of a high melt strength polypropylene (HMS-PP) with carboxyl-functionalized multiwall carbon nanotubes (MWCNTCOOH) were produced using azodicarbonamide (AZO) as the blowing agent. Compositions with 1.5, 3 and 5 wt% of MWCNTCOOH and 2.5wt% of AZO were obtained by mixing in a torque rheometer (Haake, 170 oC, 120 rpm, 10 min), foaming in a press (Marconi, 190 oC, 1 ton, 10 min) and cooling with water. Thermal, morphological, rheological, dynamic and electrical characterizations were done using differential scanning calorimetry, polarized optical and scanning electron microscopies, stress controlled rheometry , dynamic mechanical analysis and impedancimetry, respectively. A closed cell morphology was obtained in all the compositions. The 3wt% sample had the highest cellular density (16885 cells/cm2), the lowest first normal stress difference N1 and the highest damping coefficient (tan ) of all compositions. On the other hand, the 5 wt% composition had the highest zero shear viscosity o of all samples. The electrical conductivities of the 3 and 5wt% compositions were the highest (1.1 x 10-5 and 3.2 x 10-5 S/m, respectively) while of the 1.5 wt% composition was the lowest (2.3 x 10-12 S/m). Therefore, an addition of only 3 wt% of MWCNTCOOH allowed obtaining a high damping and conductive foam, with potential use as an electrostatic discharge materials.