Mechanical Properties of PPS/PC/GF/Nano-CaCO3 Hybrid Composites

A kind of nanometer calcium carbonate (nano-CaCO₃) filled glass fibre-reinforced polyphenylene sulfide/polycarbonate (PPS/PC/GF) hybrid composites were fabricated with a twin-screw extruder in this paper, and the surface of the nanometer particles was pretreated with stearic acid in a high speed mixer before melt blending. The Young's modulus, tensile strength, tensile elongation at break, flexural modulus and strength of these hybrid composites were measured at room temperature by using a universal materials testing machine, to identify the influence of the nano-CaCO₃ content on the mechanical properties of these hybrid composites. It was found that there were relatively evident reinforcing and toughening effects of the nano-CaCO₃ on the PPS/PC/GF hybrid composites. The Young's modulus, tensile strength, flexural strengt and elongation at break of these composites increased nonlinearly with an addition of the nano-CaCO₃ weigh fraction (φ _f ) when φ _f was less than 6%, and they reached the maximum at φ _f of 6%, and then decreased; while the flexural modulus increased as φ _f was less than 4%, and then decreased.     

Impact fracture toughness and morphology of polypropylene nanocomposites

The nanometer calcium carbonate (nano-CaCO₃)-filled polypropylene (PP) composites were prepared using a twin-screw extruder, and the filler particle surface was pretreated, respectively, with fat acid (SI) and titanate coupling agent (SII) in this article. The notched and unnotched impact fracture properties were measured at room temperature by means of a Charpy impact instrument to identify the effects of the surface treatment and the filler concentration on the impact fracture properties. The results showed that the V-notched and U-notched impact strength slightly increased with an addition of the nano-particle volume fraction (ϕ _f) for both two nanocomposites. When ϕ _f was more than 10%, the V-notched impact strength of the system SII was obviously greater than that of the system SI, and the effect of surface treatment of the nanometer particles on the U-notched impact strength is insignificant. Furthermore, the impact fracture surface was observed by means of scanning electron microscopy to understand the relationship between the interfacial morphological structure and the impact fracture toughness of the PP nanocomposites.     

Morphology and mechanical properties of PP/POE/nano‐CaCO3 composites

The mechanical properties including tensile, flexural, and impact of the nanometer on calcium carbonate (nano‐CaCO₃) filled polypropylene (PP)/poly (ethylene‐co‐octene) (POE) composites were measured at room temperature to identify the effects of the POE content on the mechanical properties. It was found that the Young's modulus, tensile strength, and tensile elongation at break decreased nonlinearly while the tensile fracture strength varied slightly with increasing the POE weight fraction; the V‐notched and unnotched Izod impact fracture strength increased nonlinearly with an increase of the POE weight fraction; the flexural modulus and strength decreased roughly linearly with increasing the POE weight fraction. Furthermore, the impact fracture surface of the specimens was observed by means of a scanning electronic microscope to discuss the toughening mechanisms. POLYM. COMPOS., 37:539–546, 2016. © 2014 Society of Plastics Engineers     

Effects of the glass bead content and the surface treatment on the mechanical properties of polypropylene composites

Polypropylene composites filled with glass beads (GBs) were prepared by means of a twin‐screw extruder. The tensile properties and impact‐fracture strength of the composites were measured at room temperature to identify the effects of the GB content and surface treatment on the mechanical properties. The results show that the relative elastic modulus increased nonlinearly, whereas the tensile strength decreased with increasing GB volume fraction (?_f). The notched impact strength increased with increasing ?_f when ?_f was less than 11%, and then, it decreased; this might have been related to the GB aggregation in the case of higher concentration. The mechanical properties of the composite systems in which the GB surface was treated with silane coupling agent were better than those of the composite systems filled with the untreated GBs under the same conditions. Furthermore, the impact‐fractured surfaces were observed with a scanning electron microscope to understand the interfacial morphology between the inclusion and the matrix and to examine the toughening mechanisms. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Mechanical properties of mica‐filled PBT/ABAS composites

Tensile properties and Izod impact strength of mica‐filled composites of poly(butylene terephthlate) (PBT)/polyacrylonitrile‐butyl acrylate‐styrene (ABAS) were studied at mica concentration range 0 to 0.14 volume fraction, (?_f). Tensile properties such as tensile modulus, strength, and breaking strain were normalized by dividing the data with the crystallinity (%) of the major component PBT in the composites and the matrix blends. The normalized relative tensile properties were compared with simple models to evaluate the interphase interactions between the matrix (i.e. PBT/ABAS blend) and the dispersed phase mica. Mica reinforced the blend increasing the tensile modulus and strength with mica concentration while the strain‐at‐break was increased marginally up to ?_f = 0.04 and decreased beyond this ?_f. The impact strength, however, decreased with increase in ?_f due to enhanced matrix stiffening and lack of plastic deformation of the matrix. Scanning electron microscopic studies revealed good dispersion of mica in the composites. The effect of surface treatment with a zirconate coupling agent, NZ‐97, on the above properties has also been examined. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Effect of Nano-CaCO3 on Mechanical and Thermal Properties of Polyamide Nanocomposites

Polyamide-CaCO₃ nanocomposites were prepared by melt intercalation on twin-screw extruder. Various particle sizes (23, 17 and 11 nm) of CaCO₃ were synthesized by in-situ deposition technique. The shape and sizes of nano-CaCO₃ particles were confirmed by transmission electron microscopy (TEM). Nano-CaCO₃ was added from 1 to 4 wt% in the polyamide. Properties such as Tensile strength, Elongation at break, Hardness, and Flame retardency were studied. These results were compared with commercial CaCO₃ filled composites. Nano-CaCO₃ filled in polyamide shows, 3 fold improvement in Young's modulus in comparison to commercial CaCO₃ and 4–7 folds to virgin polyamide. Besides that, a polyamide nanocomposite shows 2 times improvements in flame retarding and vicat softening properties compared to commercial CaCO₃. Moreover, thermal degradation was studied on TGA and found to be improved compared to commercial CaCO₃. This was due to uniform dispersion of nano-CaCO₃ with greater surface area in comparison to commercial CaCO₃ in the polyamide matrix. Extent of dispersion of nano-CaCO₃ was studied along with microcracks generated during tensile testing using scanning electron microscope (SEM).     

A study of the mechanical properties of randomly oriented short banana and sisal hybrid fiber reinforced polyester composites

The mechanical performance of short randomly oriented banana and sisal hybrid fiber reinforced polyester composites was investigated with reference to the relative volume fraction of the two fibers at a constant total fiber loading of 0.40 volume fraction (V_f), keeping banana as the skin material and sisal as the core material. A positive hybrid effect is observed in the flexural strength and flexural modulus of the hybrid composites. The tensile strength of the composites showed a positive hybrid effect when the relative volume fraction of the two fibers was varied, and maximum tensile strength was found to be in the hybrid composite having a ratio of banana and sisal 4 : 1. The impact strength of the composites was increased with increasing volume fraction of sisal. However, a negative hybrid effect is observed when the impact strength of the composites is considered. Keeping the relative volume fraction of the two fibers constant, that is, banana : sisal = 0.32 : 0.08 (i.e., 4 : 1), the fiber loading was optimized and different layering patterns were investigated. The impact strength of the composites was increased with fiber loading. Tensile and flexural properties were found to be better at 0.40 V_f. In the case of different layering patterns, the highest flexural strength was observed for the bilayer composites. Compared to other composites, the tensile properties were slightly higher for the composite having banana as the skin material and sisal as the core material. Scanning electron micrographs of the tensile and impact fracture surfaces of the hybrid composites having volume fraction 0.20 and 0.40 V_f were studied. The experimental tensile strength and tensile modulus of hybrid composites were compared with those of theoretical predictions. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1699–1709, 2005     

Impact fracture toughness and morphology of diatomite‐filled polypropylene composites

Impact fracture strength is an important characterization for impact toughness of materials. A polypropylene (PP) filled with diatomite with different diameter (5, 7, and 13 μm) was fabricated by means a twin‐screw extruder. The impact fracture strength of these composites was measured at room temperature to identify the effects of diatomite content and diameter on impact fracture strength of filled polypropylene composites. The results showed that the influence of diatomite on the notched impact strength was significant. When the volume fraction of the diatomite (?_f) was less than 10%, the notched impact strength (σ_I) increased quickly with an addition of ?_f, and then the variation of σ_I was slight. The notched impact strength of the composite with the diatomite diameter of 7 μm is the highest when ?_f was 10%. Furthermore, the impact fracture surface was observed by using a scanning electronic microscope (SEM) to study the toughening mechanisms. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers     

Effect of Inorganic Filler on the Crystallization,Mechanical Properties and Rheological Behavior of Poly(trimethylene terephthalate)

Poly(trimethylene terephthalate) filled with nano-CaCO₃ and ultra-fine talc was prepared by melt blending using a co-rotating twin screw extruder. The effect of these two inorganic filler on the crystallization and melting behavior, mechanical properties and rheological behavior of PTT were characterized. The DSC results indicated that both nano-CaCO₃ and ultra-fine talc exhibited heterogeneous nucleation effect on the crystallization of PTT, and more significant nucleation effect were observed in PTT/nano-CaCO₃ composite due to the smaller size and better dispersion of nano-CaCO₃ in PTT matrix. Mechanical properties study suggested that the incorporation of nano-CaCO₃ and ultra-fine talc greatly improved the tensile and flexural properties of PTT. Ultra-fine talc tends to lower the impact properties, while nano-CaCO₃ tend to increase the impact strength of the PTT/nano-CaCO₃ composite. When 2 wt.% of nano-CaCO₃ was added, the impact strength increased by one time. Rheological behavior study indicated nano-CaCO₃ exhibited plasticization effect on PTT melt and decreased the viscosity of PTT, while ultra-fine talc increased the viscosity of PTT due to the hindrance of the layer structure of talc.     

Silica‐filled polypropylene composites: The effect of ethylene diamine dilaurate and maleic anhydride grafted polypropylene on mechanical properties,water absorption,morphology, and thermal properties

The effect of two compatibilizers, i.e. ethylene diamine dilaurate (EDD) and maleic anhydride grafted polypropylene (MAPP) on the mechanical properties, water absorption, morphology, and thermal properties of silica‐filled polypropylene (PP/Sil) composites were studied. The results show that the tensile, impact and flexural strengths (up to 2 php), Young's modulus, and elongation at break (Eb) increased with increasing EDD content. However, increasing MAPP content increases the tensile strength, Young's modulus, impact and flexural strengths, and water absorption resistance. At a similar compatibilizer content, EDD exhibits higher Eb, impact and flexural strengths but lowers tensile strength, Young's modulus, and water absorption resistance compared with MAPP. Scanning electron microscopy study of tensile fractured surfaces exhibits the evidence of better silica‐PP adhesion with MAPP and EDD compared with the similar composites but without compatibilizer. Fourier transform infra red spectra provide an evidence of interaction between EDD or MAPP with PP/Sil composites. Termogravimetry analysis results indicate that the addition of EDD or MAPP slightly increases the thermal stability of PP/Sil composites. Differential scanning calorimetry also indicates that PP/Sil composites with EDD or MAPP have higher heat fusion (ΔH_f(com)) and crystallinity (X_com) than similar composites but without compatibilizer. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers     

Effect of filler content and surface treatment on the tensile properties of glass‐bead‐filled polypropylene composites

The tensile properties of polypropylene (PP) filled with two A‐glass beads with the same size, PP/3000 (glass bead surface pretreated with a silane coupling agent) and PP/3000U (no surface pretreatment), have been measured by using an Instron materials testing machine at room temperature, to identify the effects of the filler surface pretreatment and its content on the tensile properties of these composites. The results show that the Young's modulus E_c of the composites increases non‐linearly with increasing volume fraction of glass beads ϕ_f, while the tensile yield strength σ_yc and tensile stress at break σ_bc of the composites decrease with an increase of ϕ_f, in the ϕ_f range 0–30%. Furthermore, the values of E_c and σ_bc of the PP/3000 system are somewhat higher than those of the PP/3000U system under the same test conditions, but this is in contrast to the tensile strain at break ε_bc and tensile fracture energy E_bc, especially at higher ϕ_f values. Good agreement is shown between the measured tensile strength and the predicted value by using an equation proposed in previous work. In addition, ε_bc and E_bc reach maximum values at ϕ_f = 25% for both systems. This indicates that there is a brittle–ductile transition for the composites in tension. © 2000 Society of Chemical Industry     

Micromechanics for fiber volume percent with a photocure vinyl ester composite

Micromechanics for fiber volume percent (V_f) from 0.0V_f to 54.0 V_f were conducted using (3 mm long × 9 μm diameter) high‐purity quartz fibers in a visible‐light vinyl ester particulate‐filled photocure resin. MTS fully articulated four‐point bend fixtures were used with a 40 mm test span and 50 × 2 × 2 mm³ sample dimensions. Specimens were tested following the combined modified ASTM standards for advanced ceramics ASTM‐C‐1161–94 and polymers ASTM‐D‐6272–00 for modulus, flexural strength, and yield strength. Experimental data provided reliable statistical support for the dominant fiber contribution expressed through the rule‐of‐mixtures theory as a valid representation of micromechanical physics. The rule‐of‐mixtures micromechanics described by V_f could explain 92, 85, and 78% of the variability related to modulus, flexural strength, and yield strength respectively. Statistically significant improvements with fiber addition began at 10.3V_f for modulus, 5.4V_f for flexural strength, and 10.3V_f for yield strength, p < 0.05. In addition, correlation matrix analysis was performed for all mechanical test data. An increase in V_f correlated significantly with increases in modulus, flexural strength, and yield strength as measured by the four‐point bending test, p < 10⁻¹⁰. All mechanical properties in turn correlated highly significantly with one another, p < 10⁻⁹. POLYM. COMPOS., 28:294–310, 2007. © 2007 Society of Plastics Engineers     

Mechanical properties of teak wood flour‐reinforced HDPE composites

Mechanical properties such as tensile and impact strength behavior of teak wood flour (TWF)‐filled high‐density polyethylene (HDPE) composites were evaluated at 0–0.32 volume fraction (Φ_f) of TWF. Tensile modulus and strength initially increased up to Φ_f = 0.09, whereas a decrease is observed with further increase in the Φ_f. Elongation‐at‐break and Izod impact strength decreased significantly with increase in the Φ_f. The crystallinity of HDPE also decreased with increase in the TWF concentration. The initial increase in the tensile modulus and strength was attributed to the mechanical restraint, whereas decrease in the tensile properties at Φ_f > 0.09 was due to the predominant effect of decrease in the crystallinity of HDPE. The mechanical restraint decreased the elongation and Izod impact strength. In the presence of coupling agent, maleic anhydride‐grafted HDPE (HDPE‐g‐MAH), the tensile modulus and strength enhanced significantly because of enhanced interphase adhesion. However, the elongation and Izod impact strength decreased because of enhanced mechanical restraint on account of increased phase interactions. Scanning electron microscopy showed a degree of better dispersion of TWF particles because of enhanced phase adhesion in the presence of HDPE‐g‐MAH. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Three‐dimensionally braided carbon fiber–epoxy composites,a new type of materials for osteosynthesis devices. II. Influence of fiber surface treatment

Interfacial adhesion between carbon fiber and epoxy resin plays an important role in determining performance of carbon–epoxy composites. The objective of this research is to determine the effect of fiber surface treatment (oxidization in air) on the mechanical properties (flexural strength and modulus, shear and impact strengths) of three‐dimensionally (3D) braided carbon‐fiber‐reinforced epoxy (C_3D/EP) composites. Carbon fibers were air‐treated under various conditions to improve fiber–matrix adhesion. It is found that excessive oxidation will cause formation of micropits. These micropits are preferably formed in crevices of fiber surfaces. The micropits formed on fiber surfaces produce strengthened fiber–matrix bond, but cause great loss of fiber strength and is probably harmful to the overall performance of the corresponding composites. A trade‐off between the fiber–matrix bond and fiber strength loss should be considered. The effectiveness of fiber surface treatment on performance improvement of the C_3D/EP composites was compared with that of the unidirectional carbon fiber–epoxy composites. In addition, the effects of fiber volume fraction (V_f) and braiding angle on relative performance improvements were determined. Results reveal obvious effects of V_f and braiding angle. A mechanism was proposed to explain the experimental phenomena. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1040–1046, 2002     

Degradation behavior of SiO2f/Al2O3-SiO2 composites: Anti-oxidation behavior and high-temperature flexural strength

2.5-Dimensional SiO₂ fiber-reinforced Al₂O₃-SiO₂ (SiO_2f/Al₂O₃-SiO₂) composites were prepared by the sol-gel method, using diphasic SiO₂ sol as the precursor into which Al₂O₃ powders were added. Their antioxidative behaviors and flexural strengths at high temperature were tested and compared. In an oxidation atmosphere, the composites showed high oxidation resistance, with a flexural strength retention ratio of over 90.00% at 1200?°C. After oxidation at 1500?°C, the mass retention ratio and flexural strength were 97.49% and 65.0?MPa respectively. The oxidation resistance of SiO_2f/Al₂O₃-SiO₂ composites was higher than that of SiO_2f/SiO₂ composites. After high-temperature test, the flexural strength retention ratios of SiO_2f/SiO₂ and SiO_2f/Al₂O₃-SiO₂ composites were 86.18% and 94.80% respectively, and the latter had a flexural strength of 134.9?MPa. SiO_2?f/Al₂O₃-SiO₂ composites worked better than SiO_2f/SiO₂ composites did in the flexural strength test at 1200?°C. The mechanical performance degradation and mass variations of the composites during tests were closely associated with their microstructural evolutions.     

Investigation of the microstructures,properties, and toughening mechanism of polypropylene/calcium carbonate toughening masterbatch composites

The morphologies, crystallization and melting behaviors, and mechanical, thermal and processing properties of polypropylene (PP)/CaCO₃ toughening masterbatch (CTM) composites were investigated. The good dispersion of CaCO₃ particles via appropriate surface encapsulation in the composites is proven by density measurements and scanning electron microscopy images. The crystallinity and tensile strength of PP decrease with the addition of CTM. The flexural modulus and storage modulus (E′) at 23 °C increase with CTM content, implying improved stiffness. A sharp increase in the Izod notched impact strength can be observed for the composites, and the critical ligament thickness (τ_c) is calculated to be 1.31 and 2.46 μm for PP (S1003) and PP (001 G) composites, respectively. The morphologies of the impact‐fractured surfaces of the specimens were observed, and the shear deformation is enhanced by the addition of CTM. The presence of CTM also increases the melt flowability and decreases the shrinkage of the composites. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45515.     

纳米碳酸钙性质对聚氯乙烯复合材料界面及性能的影响

选择了不同的表面处理剂对纳米CaCO₃进行表面改性. 研究了不同表面处理剂对CaCO₃/PVC纳米复合材料微观结构、界面结合强度、力学性能及加工性能的影响.研究表明,钛酸酯偶联剂处理可使纳米CaCO₃颗粒在PVC基体中达到良好分散,明显改善纳米CaCO₃颗粒与PVC基体之间的界面结合,并提高其界面结合强度.力学性能和流变性能研究表明,钛酸酯处理的纳米CaCO₃填充PVC具有更高的拉伸强度、冲击强度以及更低的平衡转矩, 而且CaCO₃/PVC复合材料的冲击韧性在填充量为20%(mass)时达到最大值26.5 kJ&#8226;m^-2,是纯PVC的4倍.     

Mechanical properties of blocked polyurethane/epoxy interpenetrating polymer networks

The mechanical properties of blocked polyurethane(PU)/epoxy interpenetrating polymer networks (IPNs) were studied by means of their static and damping properties. The studies of static mechanical properties of IPNs are based on tensile properties, flexural properties, hardness, and impact method. Results show that the tensile strength, flexural strength, tensile modulus, flexural modulus, and hardness of IPNs decreased with increase in blocked PU content. The impact strength of IPNs increased with increase in blocked PU content. It shows that the tensile strength, flexural strength, tensile modulus, and flexural modulus of IPNs increased with filler (CaCO₃) content to a maximum value at 5, 10, 20, and 25 phr, respectively, and then decreased. The higher the filler content, the greater the hardness of IPNs and the lower the notched Izod impact strength of IPNs. The glass transition temperatures (T_g) of IPNs were shifted inwardly compared with those of blocked PU and epoxy, which indicated that the blocked PU/epoxy IPNs showed excellent compatibility. Meanwhile, the T_g was shifted to a higher temperature with increasing filler (CaCO₃) content. The dynamic storage modulus (E′) of IPNs increased with increase in epoxy and filler content. The higher the blocked PU content, the greater the swelling ratio of IPNs and the lower the density of IPNs. The higher the filler (CaCO₃) content, the greater the density of IPNs, and the lower the swelling ratio of IPNs. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1826–1832, 2006     

Mechanical properties of talc‐ and (calcium carbonate)‐filled poly(vinyl chloride) hybrid composites

The main objective of this study was to investigate and compare the mechanical properties of poly(vinyl chloride) (PVC) composites filled with calcium carbonate (CaCO₃), talc, and talc/CaCO₃. Talc and CaCO₃ with different grades were incorporated into the PVC matrix. To produce the composites, the PVC resin, fillers, and other additives were first dry‐blended by using a laboratory mixer before being milled into sheets in a two‐roll mill. Test specimens were prepared by compression molding, after which the mechanical properties of the composites were determined. Single and hybrid filler loadings used were fixed at 30 phr (parts per hundred parts of resin). Talc‐filled composite showed the highest flexural modulus and the lowest impact strength, whereas uncoated, ground, 1‐μm CaCO₃ (SM 90) showed optimum properties in terms of impact strength and flexural modulus among all grades of CaCO₃. It was selected to combine with talc at different ratios in the hybrid composites. The impact strength of the hybrid composites gradually increased with increasing SM 90 content, but the flexural and tensile properties showed an opposite behavior. Hybrid (10 phr talc):(20 phr SM 90)‐filled PVC composite reached a synergistic hybridization with balanced properties in impact strength, as well as flexural and tensile properties. J. VINYL ADDIT. TECHNOL., 2012. © 2012 Society of Plastics Engineers     

Effect of g-C3N4 nanofiller as filler on mechanical properties of multidirectional glass fiber epoxy hybrid composites

An experimental study was carried out to investigate the flexural strength of glass-fiber-reinforced (multidirectional woven glass fiber) epoxy hybrid composites filled with different proportions (1, 1.5, 2, 2.5, and 3%) of graphitic carbon nitride (g-C₃N₄) filler. g-C₃N₄ powder filled glass epoxy composites were fabricated in conventional hand lay-up method. Results showed an increase in flexural strength of g-C₃N₄ particles content by 2% and beyond which the strength decreased. With the addition of 2 wt % of g-C₃N₄ in glass-fiber-reinforced epoxy composites, the tensile strength increased by 11% and the flexural strength increased by 13%. The eroded surface of the specimen was observed under scanning electron microscope and the results are reported. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48413.