Cloisite 20A Based Polyaniline Nanocomposites for Nitrogen Dioxide (No2) Gas Sensors

Compacted polyaniline (PANI)/Layered silicate nanocomposites have been successfully prepared by simple in situ, core-shell, and ex situ polymerization routes using AnHCl as a predecessor through chemical oxidation method. The structure, chemical groups, electronic transition and properties were investigated by XRD, SEM, HRTEM, UV Visible, DC electrical conductivity, TGA, and DSC. The XRD results reveals that HCl-treated Cloisite 20A, and PANI-ES/Cloisite 20A nanocomposites are delaminated. Flake-like morphologies were observed in Cloisite 20A and HCl-treated Cloisite 20A, whereas different rate of compacted fibrous morphologies of prepared PANI-ES/Cloisite 20A nanocomposites were observed as evident from SEM images. The Si-O FTIR band position does not change even after HCl treatment of Cloisite 20A, but different FTIR peaks positions of PANI-ES/Cloisite 20A nanocomposites were shifted from pure PANI-ES peaks after using Cloisite 20A nanoclays. UV-Visible spectra indicated the increment of charge carrier within the PANI-ES/Cloisite 20A nanocomposites compared to the pure one. The prepared nanohybrids showed significantly improved thermal property compared to pristine PANI-ES as clear from TGA and DSC analysis. The highest DC electronic conductivity of nanocomposite prepared by core-shell route is found to be 5.12 S/cm using linear four probe techniques. In addition, the charge transport mechanism was understood with and without loading Cloisite 20A in PANI-ES. The conductivity data supported the temperature-dependence relationship σ(T) = σ0.exp[-To/T)1/4] and followed characteristic of three-dimensional variable-range hopping (3D‒VRH) mechanism. In addition, we were discussed the response of Nitrogen dioxide (NO2) gas with polyaniline based sensor materials.

НАНОКОМПОЗИТЫ НА ОСНОВЕ ПОЛИПРОПИЛЕНА

Проведены исследования по выявлению условий формирования нанокомпозитов на основе изотактического полипропилена (ПП), малеинизированного ПП (ППМА) и их смесей с модифицированным монтмориллонитом (ММТ Cloisite 20A). Выявлены условия формирования эксфолиированных и интеркалированных нанокомпозитов в зависимости от концентрации Cloisite 20A и соотношения составов ПП/ППМА. Обнаружено усиление по модулю упругости для эксфолиированных нанокомпозитов более чем на 40 % при сохранении относительного удлинения при разрушении.

Miscibility, microstructure, and in situ cure analysis of epoxy–SAN–cloisite 20A nanocomposites

Reaction induced phase separation is a characteristic of thermoset/thermoplastic blend systems.

Recycled HDPE/PET Clay Nanocomposites

Recycling waste plastics will support the preservation of natural resources and energy consumption. New challenges arise for the development of products that take advantage of solid waste. Upgrading recycled plastics using nanotechnology can tailor and consequently improve plastic properties for industrial applications. This research aims to process and relate the morphology and thermo-mechanical properties of recycled high-density polyethylene (rHDPE) and recycled polyethylene terephthalate (rPET) clay nanocomposites. Blends of rHDPE (75 wt %) coming from packaging and rPET (25 wt %) from bottles were mixed with two organoclays (Cloisite 20A and Cloisite 30B) (3 wt %) and a compatibilizer agent based on ethylene-glycidyl methacrylate (EGMA) (5 wt %). The recycled plastics nanocomposites were processed using a single-screw extruder incorporating a dispersive and distributive mixer and an injection molding machine. Several techniques were used to characterize the dispersion, morphology, mechanical properties and compatibilization of these composite blends. The reinforcing effect of rPET in the continuous rHDPE phase depended on the organoclay type and the compatibilizer additive. Both organoclays increased the stiffness and strength of rHDPE and rPET as evidenced by an increase in the corresponding Young modulus and ultimate tensile strength. EGMA increased the compatibility in the recycle plastics blend and in the clays nanocomposites as evidenced in elongation and energy at break results. On the other side, Cloisite 20A showed to be more compatible with EGMA than Cloisite 30B in these rHDPE/rPET blends based on the thermo-mechanical properties results.

Optimising cure cycle of unsaturated polyester nanocomposites using directed grid search method

In this research, a method is proposed for optimising cure cycle of neat unsaturated polyester (UP) resins, and UP resins containing Cloisite 20A (UP/20A), in thin parts. Using the proposed optimisation method, optimised cure cycles for both neat UP resin system and UP/20A were calculated. Results of dynamic mechanical analysis tests show that samples cured by the optimised cure cycles are slightly different from those samples cured using a long-term cure cycle in terms of structural relaxation. This confirms that the proposed optimisation method not only reduces the cure cycle duration efficiently but also preserves the quality of the samples.