Enhanced Properties of PBT/PC Blends with the Addition of Carboxyl-functionalized Multiwalled Carbon Nanotube

Abstract

Carboxyl-functionalized multiwalled carbon nanotube (c-MWCNT) was used to enhance the properties of poly(butylene terephthalate)/polycarbonate (PBT/PC) blends by melt blending. The c-MWCNT inhibited transesterification reactions between PBT and PC. SEM result showed that most of the c-MWCNT dispersed in the PBT matrix and partial c-MWCNT lied between the interface of PBT and PC phases. c-MWCNT promoted the crystallization of PBT due to the decreased transesterification and the heterogeneous nucleating effect, which led to a 20 o C increase of the crystallization temperature. DMA test indicated that the miscibility between PBT and PC decreased with the c-MWCNT loading since the inhibited transesterification. When the c-MWCNT content was 4 wt%, the yield strength of 65.9 MPa and tensile modulus of 2116 MPa were achieved, which corresponded to 23.9 and 19.5% increase relative to the pure PBT/ PC blend. The conductivity and dielectric properties of PBT/PC were largely enhanced by the c-MWCNT. The σ d c values of PBT/PC improved greatly by several orders of magnitude from 10-1 8 to 10-7 when the c-MWCNT content was 2 wt%. The dielectric constant at 100 Hz for the nanocomposites increased from 2.8 to 146 when the c-MWCNT loading varied from 0.1 to 4 wt%, which improved more than 50 times.

Review on transesterification in polycarbonate–poly(butylene terephthalate) blend

“…Unique transesterification chemistry [2,4,5,9,6,12,20,8,11,21,35,52,[60][61][62][63][64][65][66][67][68][69][70] Mechanical and Morphology [1,4,13,21,22,36,48,56,35,68] Chemical resistance [4,5,26,44,45] Rheology and Processing [26, 43-49, 8, 46, 52, 54, 63, 66, 67] Recycling [58] Flame retardant characteristics [69] Impact modification [12,19,21,23,25,55,43,35,[60]…”