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In order to compare the performance of the neat epoxy-amine network and the same network with dispersed multi-walled carbon nanotubes. The curing reaction, rheology, thermal and electrical conductivity, mechanical performance and microstructure of epoxy-amine systems were investigated in this study. The curing schedule of the epoxy-amine systems was formulated depends on the parameters of the curing reaction. The processing windows and processing time of epoxy-amine systems were provided by using rheological analysis. The thermal and electrical conductivity of epoxy-amine network with dispersed multi-walled carbon nanotubes were enhanced. The mechanical performance of the epoxy-amine network was improved after introducing the dispersed multi-walled carbon nanotubes.

A bis-hydroxy terminated polyphenylene oxide (MPPO) modification was tried for the purpose of simultaneously enhancing the processability and heat resistance of epoxy resin. The thermal stability, ...

Composites of poly(lactic acid) with wood flour which was grafted by melt extruding with methyl acrylate in the presence of benzoyl peroxide (BPO) were investigated. The modification of filler (WF-g-PMA) was carried out to enhance the filler-matrix interactions, while the treated component was characterized by infrared spectrum. Properties of binary (PLA/WF, PLA/WF-g-MA) composites were analyzed as a function of the grafting monomer amount by scanning electron microscopy, differential scanning calorimeter, thermogravimetric analysis, water absorption and mechanical tests. Compared with the untreated system (PLA/WF), all treated composites showed higher interfacial compatibility as a result of chemical bonding between WF and grated monomer. All composites showed higher tensile modulus and lower strength and elongation at break as compared to pure PLA; grafting modification with methyl acrylate led to an increased stiffness and decreased water absorption of the composites because of an enhanced fill...

In this paper, a benzoxazine-based (BZ) adhesive with high temperature resistant was developed by blending benzoxazine monomer and tetrafonctional epoxy monomer as matrix modifier and polyetherimide as toughening agent. The results show that benzoxazine-based film adhesive could be cured at 190 °C, and the cured film adhesive exhibited high temperature resistance and a high glass transition temperature of 224 °C. The 5% weight loss temperature in air was 400 °C and the char yield in nitrogen at 800 °C was 48%. The cured film adhesive has good ablation resistance. The fabricated benzoxazine-based film adhesive has high adhesion reliability, with single-lap shear strength of 23.20, 28.36 and 20.04 MPa at room temperature, 140 and 175 °C respectively. The curing process of the film adhesive matches well with that of carbon fiber reinforced BZ prepreg and the film adhesive has stable adhesion properties. Its biggest advantage is that, during storage and transportation, there is no need of refrigeratio...

In this study, composites of thermoplastic poly (lactic acid) filled with wood flour (WF) were prepared via melt extrusion. Before that, alkali treatment was performed on WF to improve the properties of the WF/PLA composite materials. The effect of the solution concentrations of NaOH, namely 0.5, 1.0, 5.0, and 10.0%, on mechanical properties of the composites was evaluated. The results showed that the properties of the composites with treated WF were enhanced greatly compared with that of the untreated composites. The composites had a best improvement in its compatibility and mechanical strength when the concentration of NaOH solution was 5.0%. The brittle fracture of composites showed that the chemical modification of WFs improved the compatibility between the filler and matrix.

Utilizing corn starch as a main raw material to prepare starch adhesive, polyvinyl alcohol, borax, and carboxymethyl cellulose (CMC) were added in the preparation process. Because of the poor water resistance of native starch adhesive, an isocyanate prepolymer as a cross-linking agent was synthesized and added to improve its water resistance. Three-layer wood panels were fabricated and bonding strength was measured. The differential scanning calorimeter (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and energy dispersive X-ray spectroscopy (EDX) were used to characterize the thermal properties, morphology, and element content of samples. Effects of R value (the molar ratio of isocyanate group to hydroxyl group) and CMC addition on the physicochemical properties of starch adhesive were investigated. Thermal analysis results showed prepolymer/starch adhesive (PSA) cured at a relatively low temperature and thermal stability was improved af...

Acid-thinned starches (ATSs) have been prepared directly from hydrochloric acid-modified corn starch. The fracture mechanism of starch granule was investigated using scanning electron microscopy combined with laser particle size analysis. And the extent of ATSs chain was also first characterized using X-ray photoelectron spectroscopy. The properties of ATS were tested by X-ray diffraction, differential scanning calorimetry, thermo gravimetric analysis, and rotational viscometry. Native starch and ATSs exhibit different structures and properties. Amorphous regions of corn starch, located in the interior of the starch granule, are preferentially hydrolyzed and can lead to starch particle fracture. The relative C=O content in the ATSs are increased, indicating that the acid thinning makes the starch molecules shorter, and the fracture extent of the starch molecular chains was 240.86 and 608.97%, respectively. Acid thinning does not change the starch crystal pattern or its basic composition, but it does incre...

In this work sodium bisulfate was used as a blocking agent to block polymethylene polyphenylisocyanate (PAPI). The particle size distribution rate and the factors influencing the stability of the blocked isocyanate emulsion were studied by varying the stirring speed. Furthermore the blocked isocyanate was characterized using a variety of methods. In order to determine the best stirring speed for preparing blocked isocyanate, a laser particle size analyzer and thermo gravimetric analysis were used to the measure particle size distribution rate and the stability of the blocked isocyanate emulsion, respectively. Experimental results show that blocked rate was 96.77%, and that the blocked isocyanate emulsion dispersion was best, and had the greatest stability, at the stirring speed of 400 r/min. Different solvents were used to wash the blocked isocyanate emulsion and the freeze-dried product. Analysis by XPS, FTIR, DSC and TGA were used to characterize the blocked products, and the blocked isocyanate...