Papers by Keyword: Interfacial Adhesion

Abstract: The effect of interfacial adhesion reduction at intensification of the nanofiller initial particles aggregation was found. It can be described with a simple empirical equation. The indicated equation precision is enough for prediction of the particulate-filled polymer nanocomposites reinforcement degree. The physical grounds of this effect can be described within the framework of fractal analysis.

Abstract: The aim of this study is to evaluate the interfacial adhesion of Fused Deposition Model (FDM)-printed Acrylonitrile butadiene styrene (ABS) and Polylactic acid (PLA) bonded using commercially – available epoxy and elastomeric bonding agents. An adhesive was applied to the 3D printed specimen to quantify the interfacial resistance, the surface was then examined under an optical microscope in order to assess the reaction of the polymer to the adhesives. The results reported in the present work allow the conclusion of levels of bond improvement in the polymers.

Abstract: A facile surface modification method for PPTA-pulp was developed to improve the adhesion to rubber matrix. Tensile strength tests and SEM were used to evaluate the adhesion of PPTA-pulp with rubber matrix, and the results indicated that surface treatment of PPTA pulp in supercritical carbon dioxide fluid was an efficient method to increase interfacial adhesion between PPTA-pulp and rubber matrix. Attenuated Toyal reflectance Fourier transform infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) were used to investigate the surface structure and composition of untreated and treated PPTA-pulp in supercritical carbon dioxide fluid. The results indicated that the interaction of macromolecules, the crystal structure and the surface composition of PPTA-pulp changed during supercritical carbon dioxide fluid, particularly for the surface morphology and composition.

Abstract: The improvement of interfacial adhesion between multiwalled carbon nanotubes (MWCNTs) and epoxy resin (EP) was investigated in nanocomposites with the addition of an ionic liquid (IL, 1-Ethyl-3-methyl imidazolium tetrafluoroborate - EMIM BF₄) as interfacial adhesion promoter. MWCNT (0, 0.3 and 0.5 weight%) was dispersed in EP through diluting an MWCNT-rich masterbatch prepared in presence and absence of IL. Three point bending and compact tension (CT) fracture mechanical tests were performed on specimens with different MWCNT contents with and without IL surfactant. IL addition resulted in easier dispersion of MWCNT in the EP masterbatch. With the addition of the IL the three point bending strength, the bending modulus of elasticity and the critical force required for crack propagation have increased significantly at the optimal, 0.3 weight% MWCNT content. Scanning electron microscopic (SEM) investigation of the fracture surfaces of the CT specimens revealed that incorporation of MWCNTs and its IL-assisted dispersion produced rougher surfaces suggesting higher fracture toughness than the reference EP.

Abstract: Producing particulate filled polymer composites, even dispersion and sufficient adhesion between filler and polymer matrix is of great importance. In order to solve these issues, methodologies, such as ultrasonic dispersing and coupling agents, are proposed. The impact of particle surface modification with three different titanate coupling agents having the tradenames of TCA L44, TCA L38 and TCA K44 on paper waste sludge particles surface, polyurethane foam composite density, compressive and tensile strengths as well as water absorption and water vapour permeability is evaluated. Apparently, titanates form layer on the particle surface, thus increasing the interfacial adhesion between particles and polymer matrix. Basing on the obtained results, the optimal amount and type of titanate is 1 wt.% of TCA K44.

Abstract: The effects of surface treatment of a carbon fiber (CF) by Polyethylene-polyamine (PEPA) on the interfacial adhesion behavior and morphology of polypropylene/polystyrene (PP/PS) matrix blends filled CF composites were investigated. Effects of surface treated a commercial CF on mechanical properties are studied. Contact angle was measured to examine the changes in wettability of the carbon fiber. The chemical and morphological changes were characterized by using X-ray photoelectron spectroscopy (XPS). PP/PS/CF composites were fabricated with and without PEPA treatment, and their interlaminar fracture toughnesses were compared. The results showed that the interlaminar shear strength (ILSS) of composites has been greatly improved filled PEPA modification CF. The water contact angle of resin sample decreased 50% after addition of PEPA surface treated CF.

Abstract: In Xinjiang, by making use of cotton stalks after cotton picked, people researched and developed a kind of walling material that is cotton stalks cement-based blocks, elaborated its preparation methods, and evaluated its technology effect of cotton stalks cement-based block material. Results show that the cotton stalks cement-based block material have good properties like wide source, easy processing and wonderful performance; by soaking cotton straw broken material with alkali liquor, made cotton straw plant fiber reinforced material and the cement matrix have good interface adhesion; the block material is provided with load-bearing, heat preservation performance and cracking resistance, it can be used for low-rise buildings bearing wallboard and retaining wall of multiple floors in cotton planting region.

Abstract: This study uses a single screw extruder to make short coir (SC), an agricultural waste, high-strength short glass fiber (SGF), and polypropylene (PP) into pellets, which are then made into wood plastic composites (WPC) on an injection machine. During the process, maleic anhydride grafted polypropylene (PP-g-MA) is used as a coupling agent to improve the interfacial adhesion between coir and PP as well as between SGF and PP. A tensile strength test, flexural strength test, and Izod impact strength test are performed on the samples to examine the mechanical properties. The experiment results show that when the content of SGF increases from 3 wt% to 12 wt%, the tensile strength increases from 26.08 MPa to 36.68 MPa, and flexural strength increases from 36.01 MPa to 49.91 MPa, but the Izod impact strength decreases from 286.16 J/m to 218.14 J/m. In addition, the addition of 2 wt% of PP-g-MA improves the interfacial adhesion between matrices (PP) and reinforcement (SC or SGF), thereby fortifying the mechanical properties of the composites.

Abstract: Maleic anhydride grafted polypropylene (PP-g-MA) is used as a coupling agent, and the influence of its used amount on the mechanical properties of the polypropylene/short glass fiber (PP/SGF) composites is examined. 1, 2, and 3 wt% of PP-g-MA is separately added to PP/SGF composites that are made at an 80/20 ratio (wt%), made into pellets on a single screw extruder, and then made into test samples on an injection machine. When PP-g-MA increases from 1 wt% to 3 wt%, the tensile strength of the PP/SGF composites increases from 56.22 MPa to 64.85 MPa; likewise, flexural strength increases from 67.29 MPa to 81.24 MPa, and Izod impact strength increases from 197.70 J/m 269.61 J/m. SEM images show that the surface of SGF are encapsulated with a layer of PP matrix, which indicates that PP-g-MA can effectively improve the interfacial adhesion between PP and SGF and thus increase the mechanical properties of the resulting composites.

Abstract: The high density polyethylene (HDPE) nanocomposites were prepared by melt mixing HDPE with multi-wall carbon nanotubes (MWCNTs). In this work, the morphological, nucleation, crystallization and mechanical properties of the HDPE nanocomposites were studied by scanning electron microscopy, different scanning calorimetry, small-angle X-ray scattering and tensile testing. It was found that the tensile strength and Young’s modulus is increased by 42.4% and 116.5% at 3.wt% MWCNT loading compared to the pure HDPE. According to SEM results combined with SAXS, well-defined nanohybird shish-kebab (NHSK) entities exist in the composites, and in the shish-kebab structures fibrillous carbon nanotubes (MWCNTs) act as shish while HDPE lamellae act as kebab. The crystallization behavior, probed by DSC, suggests that MWCNTs have strong nucleation ability and shear stress plays an important role in polymer crystallization process. The mechanical properties demonstrated that the formation of the Shish-kebab structures improved the interfacial adhesion and brought obvious mechanical enhancement for the HDPE/MWCNTs nanocomposites.