The thermal diffusivity and the thermal conductivity of polypropylene-based composite polymer were simultaneously measured
with a temperature wave analysis method. We can measure the thermal properties under cooling process which are important to
consider the polymer processing. The effect of filler in the composite was analyzed by thermal diffusivity and thermal conductivity
as a function of temperature. The thermal conductivity of particle dispersed composite was confirmed as a reasonable value
and was explained with a series model.
Authors:H. Mothé Filho, M. Gonçalves, and C. Mothé
Thermal degradation of granite and marble industry reject (GMIR), a red clay (RC)and their composites were studied by non-isothermal
thermogravimetry (TG/DTG) in nitrogen atmosphere, differential thermal analysis (DTA) and derivative thermogravimetry(DTG)
in air atmosphere. Measurements were made in the temperature range of 25–1000,25–1200 and 25–1400C. The kinetic parameters
were determined by Flynn–Wall and Kissinger's methods. The results indicate the absent dominance of one mechanism of reaction,
and the composites show smaller values of kinetic parameters than GMIR or RC.
analysis of jute fibre reinforced vinylester resin with 30 vol% of fibre were
performed by TG/DTG under dynamic conditions. The fibres were treated with
alkaline solution at different temperatures and the final composition (cellulose,
hemicellulose and lignin) of the fibre was determined by chemical analysis.
Apparent activation energies were determined using a variety of conventional
thermogravimetric methods. Two peaks were found in the composite differential
curves: the first peak close to 327 and the second peak at 408°C. The
apparent activation energy values for the second peak decreased when fibre
were treated. The addition of the jute fibres produced a slightly decrease
in the thermal stability of the composites.
Formation and rheological properties of mixed protein-polysaccharide gels (composites) was studied. The composites consisted of whey proteins gelling separately, which were surrounded by polysaccharide gel. The polysaccharide gels were obtained from κ-carrageenan and κ-carrageenan-galactomannan (guar gum and locust bean gum) mixtures. The texture of gels obtained was examined by their compression and bending test. The composite gels obtained from 14% WPI solution and the 1.5% mixture of κ-carrageenan with locust bean gum in a 1:1 ratio exhibited a higher shear stress value at fracture in comparison to WPI gels, but they were less resistant to fracture in the bending test. The texture of gels was highly influenced by pH.
Crystallinity parameters and changes in the crystalline morphology with temperature of an electrically conductive composite
containing ultrahigh molecular mass polyethylene (UHMMPE) and polyaniline (PANI) doped with dodecylbenzenesulfonic acid (DBSA)
are studied for the first time by using differential scanning calorimetry and wide-angle X-ray diffraction. It is found that
during the melting of UHMMPE crystals PANI partially penetrates in the amorphous phase of the matrix polymer. Since the composite
is found to be thermally stable up to ca. 270C, it can be suggested that it would be processable without loosing conductivity
at temperatures much higher than the melting temperature of UHMMPE.
Authors:Isabelle Kraus, Shuning Li, Andrea Knauer, Marc Schmutz, Jacques Faerber, Christophe A. Serra, and Michael Köhler
This paper presents a new route to the synthesis of uniform and size-controlled inorganic/organic composite microparticles by means of microreaction technology. Au-nanoparticles in the range of 3 to 14 nm are synthesized by reduction of tetrachloroauric acid, while ZnO-nanoparticles (200–2000 nm) are synthesized in a continuous-flow two-step process using microtube arrangements for microsegmented flow. Both inorganic nanoparticles have a well-controlled size and narrow size distribution. Upon surface modification, the nanoparticles are then mixed on one hand with an acrylate-based monomer and, on the other hand, with an aqueous solution of acrylamide. Both solutions were then emulsified into uniform core-shell droplets by means of a capillary-based microfluidic device. Droplet's shell was hardened through UV-induced polymerization, whereas the core led to a hydrogel upon thermal-induced polymerization. Core-shell polymer microparticles (200–300 µm) with inorganic nanoparticles selectively incorporated into the core and the shell are thus obtained as proven by extensive morphological characterizations using electronic and optical microscopies.
Authors:Shaoxu Wang, Zihang Huang, Jianhai Wang, Yansheng Li, and Zhicheng Tan
Over the last few years, polyaniline (PANI) composites have been studied with growing interest because of their numerous applications in various electrical and electronic devices. Many articles on PANI