Single-Point Determination of Intrinsic Viscosity of Semirigid Thermotropic Copolyesters in Phenol/1,1,2,2-Tetrachloroethane

Poly(ethylene terephthalate)/multiwalled carbon nanotubes (PET/MWCNTs) with different MWCNTs loadings have been prepared by in situ polymerization of ethylene glycol (EG) containing dispersed MWCNTs and terephthalic acid (TPA). From scanning electronic microscopy images of nanocomposites, it can be clearly seen that the PET/MWCNTs composites with low-MWCNTs contents (0.2 and 0.4 wt %) get better MWCNTs dispersion than analogous with high-tube loadings (0.6 and 0.8 wt %). The nonisothermal crystallization kinetics was analyzed by differential scanning calorimetry using Mo kinetics equation, and the results showed that the incorporation of MWCNTs accelerates the crystallization process obviously. Mechanical testing shows that, in comparison with neat PET, the Young's modulus and the yield strength of the PET nanocomposites with incorporating 0.4 wt % MWCNTs are effectively improved by about 25% and 15%, respectively. V C 2011 Wiley Periodicals, Inc. J Appl Polym Sci 120: [3460][3461][3462][3463][3464][3465][3466][3467][3468] 2011

Section: Methodsmentioning

confidence: 99%

“…The intrinsic viscosity ([g]) was calculated using a single-point determination method according to the following formulation (1). 33,34…”

Section: Intrinsic Viscosity Measurementmentioning

confidence: 99%

Morphology, crystallization, and mechanical properties of poly(ethylene terephthalate)/multiwalled carbon nanotubes composites

Zhu¹,

Wang²,

Dong³

et al. 2011

Preparation of PTT/clay nanocomposites with solid‐state polymerized polytrimethylene terephthalate

Engelmann

Bonatz

Ganster

et al. 2012

To enhance the effectiveness of polytrimethylene terephthalate (PTT) for the preparation of clay-based nanocomposites by melt intercalation and to upgrade the mechanical performance of these materials, solid-state-polymerization (SSP) experiments with neat PTT were carried out at 190, 200, and 210°C prior compounding to increase the average molecular weight and, based on this, the melt viscosity of this polymer. The progress of SSP was registered by time dependent sampling of intrinsic viscosity data. From this, activation energy of 180.6 kJ mol -1 was calculated. A characteristic sublimate formed during these SSP-reactions was identified by mass-spectroscopy to be a mixture of cyclic oligomers containing 2, 3, 4, and 5 monomeric units. The melt viscosity of neat PTT(SSP) could be increased from 460 to 15,000 Pa s -1. Therefore, tensile strength and Young's modulus were improved by 3.5 and 9%, respectively. Manufacturing of PTT(SSP) and the modified nanoclay was carried out with a corotating twin-screw-extruder at 230°C. A concentration of 3% of the inorganic filler component in the composites was aimed at. Compared with the data of virgin PTT, tensile strength, and modulus of the PTT(SSP)-based nanocomposites could be enhanced by 9 and 40%, respectively. Additionally, a SSP-reaction of the nanocomposite prepared with non-pretreated PTT and nanoclay was performed at 210°C to test the robustness of the matrix polymer PTT against the influences of the nanofiller. © 2012 Wiley Periodicals, Inc

Nanocomposites based on aromatic polyesters and organically modified clay

Engelmann

Bonatz

Ganster

2012

Milled polybutylene terephthalate (PBT) and polytrimethylene terephthalate (PTT) were mixed with organically modified clay and extruded to prepare nanocomposites by melt intercalation. The modifier of the nanofiller belongs to the group of trialkylbenzylammonium cations. Manufacturing of the materials was carried out with a co-rotating twin-screw-extruder at 230°C and 240°C for PTT and PBT, respectively. A concentration of 3% of the inorganic filler component in the composites was aimed at. The influence of mechanical stress during extrusion on the stability of the neat polymers was tested at different speeds of rotation between 100 rpm and 800 rpm. The composites were characterized with regard to the experimental filler content and the properties of the matrix polymers like melt and crystallization temperatures, degrees of crystallinity, intrinsic viscosities, and melt viscosities. Additionally, mechanical properties were analyzed by tensile tests and discussed in term s of processing and the filler presence. The dominance of PBT as polymer matrix was highlighted