Notched Izod Impact Research Articles

Probing toughness of polycarbonate (PC: ductile and brittle)/polypropylene (PP) blends and talc‐triggered PC/PP brittle composites with diverse impact fracture parameters

ABSTRACTPolycarbonates (PCs) are commonly used as a blend and a composite to achieve pecuniary advantages and dimensional stability. While the toughness of a homogeneous PC matrix has been extensively investigated, examination for the toughness of heterogeneous blend systems such as PC/polypropylene (PP) blends has been limited. Furthermore, recent interest in highly flowable PCs (low‐molecular‐weight PCs with low ductility) has surfaced due to the large and geometrically complex plastic parts. Herein, the toughness for PC/PP blends and PC/PP/talc composites in a ductile and a brittle PC matrix was explored by using various toughness measurements such as notched Izod impact strength, falling dart impact, boss quasi‐static energy/impact energy, and tensile toughness tests. In a ductile PC matrix [melt flow index (MFI) = 8], the incorporation of PP gradually reduced the toughness. On the other hand, the toughness was improved by 450% at 2 wt % PP in a brittle PC matrix (MFI = 19). Similarly, in the talc‐induced brittle PC matrix, the toughness was enhanced at the PP loading from 2 to 10 wt %. The density of PC/PP blends was gradually reduced from 1.19 to 1.10 g cm−3 with increasing PP concentration from 0 to 20 wt %. Degradation, density, thermal behaviors, and morphology were also investigated. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47110.

Study of Morphological and Mechanical Properties of PBT/PTT Blends and Their Nanocomposites and Their Correlation

Impact modified PBT/PTT blends based nanocomposites having organoclay content varying from 2, 3 and 5 wt% were prepared using corotating twin-screw extruder. Organoclay (Cloisite 30B) was used as nanofiller. Ultra-low-density polyethylene-grafted glycidyl methacrylate (ULDPE-g-GMA) was used as an impact modifier to toughen the polymeric matrices. In all the prepared nanocomposites, the amount of impact modifier (ULDPE-g-GMA) remains constant, i.e., 2 wt%. Izod impact testing showed that only 2 wt% impact modifier (ULDPE-g-GMA) was enough to improve the notched Izod impact strength of the neat PBT and neat PTT by 85.6 and 98.6 %, respectively. It shows an excellent toughening of PBT and PTT with ULDPE- g-GMA rubber. It was further found that the incorporation of only 3 wt% organoclay significantly improved the tensile strength, tensile modulus values of PBT/PTT blends. The result of FEG-SEM indicated that nanocomposite with 3 wt% organoclay in PBT/PTT/2wt% ULDPE-g-GMA did not show phase separation. It showed that 3 wt% organoclay was homogeneously dispersed in impact modified PBT/PTT blends based nanocomposites. POM studies revealed that the well-defined spherulites are present in neat PBT and neat PTT when $$T_{\mathrm{c}}$$ was 205 $${^{\circ }}$$ C.

Bio-based poly(butylene 2,5-furandicarboxylate)-b-poly(ethylene glycol) copolymers with adjustable degradation rate and mechanical properties: Synthesis and characterization

Bio-based poly(butylene furandicarboxylate)-b-poly(ethylene glycol) copolymers are successfully synthesized through transesterification and melt polycondensation. The resulted polymers are characterized in terms of structural, thermal and mechanical properties. In addition, for the first time relevant hydrolytic degradation studies for the copolymers applications are systematically conducted in neutral and alkaline conditions. The PEG weight fraction ranges from 10% to 60%, as determined by 1H NMR. Isothermal crystallization tests show that the copolymers own faster crystallization rate than that of PBF, with melting temperature higher than 120 °C. Water contact angle and water uptake characterizations show that the introduction of increasing amounts of PEG improves the hydrophilic character of the copolymers. Tensile tests clearly indicate that elongation at break drastically increase with PEG content, up to 5 times compared to PBF. From the Notched Izod impact tests, most samples are unbroken in the impact testing, showing excellent impact toughness. It is surprising to find that after water uptake, the PBF-PEGs still have acceptable mechanical properties. The weight loss during hydrolytic degradation is significant after 5 weeks for most of copolymers. With fast hydrolytic degradation rate and good mechanical properties, these copolymers own potential applications in areas like biomedical industry.

Fabrication of Super Tough Polycarbonate/Styrene-Etylene-Butylene-Styrene Grafted Maleic Anhydride (SEBS-g-MA) Blends: Morphological, Short Term Static Mechanical and Fracture Performance Interpretation

ABSTRACTImpact behaviours, tensile properties and fracture performance of polycarbonate (PC)/styrene ethylene-butylene-styrene-grafted-maleic anhydride (SEBS-g-MA) copolymer blends at SEBS-g-MA volume fraction Φd = 0–0.39 are evaluated. In presence of rubber a significant augmentation in notched Izod impact strength was observed while tensile modulus and strength decreased. Morphological studies reveal good interaction between the PC and the rubber particles showing homogeneous dispersion of SEBS-g-MA in the polycarbonate matrix. Interparticle distance of the dispersed phase evaluated from the morphology studies by scanning electron microscopy (SEM) and the impact strength dependence on the concentration of the blending rubber were analysed. The essential work of fracture approach is applied to study fracture properties of the blends. With increasing SEBS-g-MA concentration nonessential or plastic work increased which explained the enhancement of impact strength of blends.

Synergistic Toughening Effect of Nucleating Agent and Annealing Treatment and Morphological Research on Block Copolymerization Polypropylene

ABSTRACTThe toughening effects of α and β nucleating agents (α-NA and β-NA) and annealing treatment on block copolymerization polypropylene (PPB) were ascertained. The synergistic effect of β-NA and the annealing treatment at 130°C for 3 h impacted the toughness greatly for all test temperatures (−15, 0 and 23°C), specifically, the notched Izod impact strength tested at −15°C increased from 7.3 kJ/m2 to 30.1 kJ/m2. Moreover, the addition of α-NA or the annealing treatment also improved the toughness of PPB. The changes of the crystallite morphology and multiphase structure play an important role on the toughening.

Mechanical properties of compression‐molded electrospun silica fiber/nylon‐6 composites

In this study, we utilized electrospun silica fibers (ESFs) as reinforcement in sandwiched nylon‐6 composites. The silica fibers were fabricated via electrospinning of sol‐gel precursor, prepared from tetraethyl orthosilicate. The process yielded non‐woven silica fiber mats with fiber diameter about 350 nm, which is much smaller than conventional glass fibers. Each ESF mat was sandwiched in between two nylon‐6 sheets and the layers were compression‐molded to produce a composite sample. These composites were prepared with varying silica fiber content, approximately at 0, 0.5, 1.0, and 1.9 wt%. The ESF blended well and chemically bonded with the nylon matrix, as observed through scanning electron microscopy and Fourier transform infrared spectroscopy. Tensile tests revealed that tensile modulus and tensile strength increased with ESF content. Notch Izod impact test showed that impact strength also increased with ESF content. The tensile and impact properties were significantly improved, considering the use of such low silica fiber percentages, which could be due to ultra‐fine fiber diameter and fiber continuity. From flexural test, however, flexural modulus and flexural strength decreased slightly by the addition of ESF. Specimen geometry and fabrication process play important roles in governing the composites mechanical behavior. POLYM. COMPOS., 40:1123–1131, 2019. © 2018 Society of Plastics Engineers

Simultaneous enhancements in electrical conductivity and toughness of selectively foamed polycarbonate/polystyrene/carbon nanotube microcellular foams

Abstract Electrically conductive polycarbonate/polystyrene/carbon nanotube (PC/PS/CNT) ternary nanocomposites are prepared by blending with styrene-maleic anhydride copolymer as their compatibilizer. Interestingly, CNTs are selectively distributed in PC phase in the PC/PS/CNT nanocomposites. After foaming with supercritical carbon dioxide as the foaming agent, most cells preferentially localize in the readily foamed PS phase; whereas, few cells appear in the PC matrix. Therefore, a selectively foamed morphology consisting of electrically conductive PC/CNT continuous phase and the foamed PS dispersed phase is well constructed. Due to the selective localization of CNTs, the PC70/PS30/CNT nanocomposite foams with PC as the matrix exhibits a much lower conducting percolation threshold of 0.35 vol% than the PC30/PS70/CNT nanocomposite foams with foamed PS as the matrix (0.94 vol%). The high electrical properties of the PC70/PS30/CNT foams are attributed to the conducting network of CNTs within the continuous PC matrix and the volume-exclusion effect of the preferentially foamed PS dispersed phase. More interestingly, PC70/PS30/1%CNT nanocomposite foam also exhibits much higher mechanical properties than PC30/PS70/1%CNT nanocomposite foam and a significant increase of 245% in notched Izod impact strength is achieved in relative to its bulk counterpart due to the toughening effect of the foamed PS particles.

Improvement of compatibility and mechanical properties of the poly(lactic acid)/poly(butylene adipate‐co‐terephthalate) blends and films by reactive extrusion with chain extender

Biodegradable poly(lactic acid)/poly(butylene adipate‐co‐terephthalate) (PLA/PBAT) blends and films were prepared by melt blending and blowing films technique in the presence of chain extender. The Joncryl ADR‐4370F (ADR) was used as the chain extender. The effect of ADR on the mechanical properties, rheological behavior, morphology, and thermal behavior of PLA/PBAT blends was investigated. The mechanical properties were markedly improved by incorporation of 0.15 phr ADR, for example, the elongation at break increased from 23.5% to 410.3% and the notched Izod impact strength increased from 7.5 to 33.4 KJ/m2 for the PLA/PBAT/ADR blends. The elongation at break increased from 17.7% to 264.6% and the tensile strength increased from 28.0 to 40.7 MPa for the PLA/PBAT/ADR films in the transverse direction. The tensile strength and tear strength of the films increased from 28.0 to 40.7 MPa and from 135.5 to 163.8 kN/m in the machine direction, respectively. Morphological observation through scanning electron microscopy revealed that the compatibility of the PLA/PBAT blends was greatly enhanced by the incorporation of ADR. The interfacial adhesion was improved between PLA phase and PBAT phase. These findings contributed new knowledge to the additives area and gave important implications for manufacturing biodegradable polymer packaging material. POLYM. ENG. SCI., 58:1868–1878, 2018. © 2017 Society of Plastics Engineers

Supertoughened Polylactide Binary Blend with High Heat Deflection Temperature Achieved by Thermal Annealing above the Glass Transition Temperature

Through thermal annealing above the glass transition temperature, a supertoughened binary blend with the highest notched Izod impact strength of 98 KJ/m2 was achieved, which was about 52 times of that of neat polylactide (PLA; 1.9 KJ/m2). The binary blend was composed of biocompatible and biodegradable PLA and ethylene–acrylic ester–glycidyl methacrylate terpolymer (EGMA) elastomer at the composition of 80/20 PLA/EGMA. For one toughened binary blend with the notched Izod impact strength of 94 KJ/m2, its tensile elongation at break was kept above 120%. Moreover, this supertoughened binary blend also displayed a much higher heat deflection temperature for application. Thermal annealing induced crystallization of the PLA matrix in the blend, and a linear correlation between the notched Izod impact strength and crystallinity was revealed. The possible toughening mechanism for the PLA/EGMA 80/20 blend with thermal annealing was analyzed from the viewpoint of negative pressure effects, as imposed on EGMA elasto...

Morphology and properties of PP in-reactor alloys prepared with a MgCl2/TiCl4/diisobutyl phthalate/phosphate tris-methylphenyl ester catalyst system

A series of polypropylene(PP)/poly(ethylene-co-propylene) in-reactor alloys with different ethylene con-tents was prepared through a two-stage polymerization process using a MgCl2/TiCl4/diisobutyl phthalate/phosphate tris-methylphenyl ester catalyst system. The ethylene content, particle shape, fractured surface, and glass-transition temperature(Tg) of the obtained PP in-reactor alloys were characterized by means of nuclear magnetic resonance, scanning electron microscopy(SEM), and dynamic mechanical analysis(DMA). The ethylene content of the PP alloys increased from 2.34% to 26.69% when the propylene/ethylene feed ratio was increased from 66/34 to 54/46(molar ratio). Morevoer, the increment in ethylene content increased the notched Izod impact strength of the resulting PP al-loys. The impact strength of the PP alloy with an ethylene content of 26.69% was 55.8 kJ/m2, which is 12.7 times that of isotactic polypropylene. The results of DMA and SEM analysis reveal that ethylene-propylene random copoly-mer(EPR) in the PP alloy has a low Tg of ca.‒50 °C and a high interface compatibility with the PP matrix. The ex-cellent impact performance of the PP alloy can be attributed to the uniform dispersal of EPR in the alloy particles and PP matrix.

Injection-Molded Bioblends from Lignin and Biodegradable Polymers: Processing and Performance Evaluation

This paper investigates the effects of the incorporation of lignin and small quantities of epoxidized natural rubber (ENR) as an impact modifying agent on blends of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and poly(e-caprolactone) (PCL). The addition of lignin resulted in a slight improvement of flexural strength and modulus of the ternary blending system. Incorporation of ENR into the blend resulted in an increase in notched Izod impact strength from 40 to 135% depending on the concentration of ENR. The addition of lignin into the blend resulted in an improvement of thermal stability of the ternary blend system. Morphological analysis showed a good dispersion of PHBV phases and lignin within the PCL matrix. Rheological characterization revealed that the presence of lignin resulted in increased storage modulus of the bioblend.

Critical rubber layer thickness of core-shell particles with a rigid core and a soft shell for toughening of epoxy resins without loss of elastic modulus and strength

Core-shell particles with a rigid silica core and a poly(butyl acrylate) (PBA) rubber shell are used to toughen epoxy resins without loss of elastic modulus and tensile strength. Both the diameter of silica core (D) and thickness of PBA shell (Ts) of silica-PBA core-shell particles are accurately controlled by sol-gel synthesis and seed emulsion polymerization process, respectively. From the results of notched Izod impact tests, a brittle-ductile transition of these epoxy/silica-PBA composites occurs when the rubber shell thickness (Ts) exceeds a critical value (Tsbd). It is found that Tsbd increases with increasing D which implies a critical rubber content (10 wt%) in the core-shell particles or a critical Ts/D ratio (0.0375), above which all composites transit from brittle to ductile failure. The composite elastic modulus decreases with increasing Ts. However, the critical thickness values of Tsm and Tss, below which composite modulus and tensile strength, respectively, are equal to or higher than the corresponding epoxy matrix values, are both larger than Tsbd. These results prove that brittle polymers can be toughened without loss of elastic modulus and tensile strength. However, the critical surface-to-surface inter-particle distance (Lc) is controlled by both properties of the core-shell particles and polymer matrix. When the rubber shell thickness Ts > Tsbd, Lc is increased when D is decreased. But when Ts < Tsbd, the brittle-to-ductile transition cannot occur, even when Lc is less than 100 nm.

Post-yield fracture correlations to morphological and micromechanical response of poly(ε-caprolactone)-based biocomposites

The present work investigates the effect of jack wood flour (JWF) content on the fracture toughness, tensile, impact, and morphological behavior of the prepared green biocomposites. From 0 to 35 wt% (volume fraction ( Φf) = 0–0.34) of JWF was incorporated as a reinforcing biodegradable filler into poly(ε-caprolactone) (PCL) matrix by melt compounding in a twin screw extruder. The tensile modulus increases by 80.48% at the highest Φf= 0.34, though marginal increment (13.71%) in the yield strength was registered. A sharp reduction in notched Izod impact strength (85%) was observed with increasing JWF content. The fracture toughness of the prepared biocomposites based on post-yield fracture mechanics concept was investigated by essential work of fracture (EWF) methodology. Incorporation of JWF into PCL matrix diminishes the EWF ( we), while increasing the non-essential work of fracture ( βwp). In the biocomposites, principally two mechanisms governed the fracture deformation. Large JWF particles act as stress concentration points and favor the crack initiation, while the smaller particles favor fibrillation which arrests the crack propagation enhancing the parameter βwpat lower concentration of JWF. Freeze-fractured surfaces show a degree of phase adhesion at lower Φfof JWF. The phase adhesion parameter obtained from micromechanical analysis of tensile properties suggesting the mechanical interlocking and interaction between PCL and JWF.

Biodegradable biocomposites from poly(butylene adipate‐co‐terephthalate) and miscanthus: Preparation, compatibilization, and performance evaluation

ABSTRACTMiscanthus fibers reinforced biodegradable poly(butylene adipate‐co‐terephthalate) (PBAT) matrix‐based biocomposites were produced by melt processing. The performances of the produced PBAT/miscanthus composites were evaluated by means of mechanical, thermal, and morphological analysis. Compared to neat PBAT, the flexural strength, flexural modulus, storage modulus, and tensile modulus were increased after the addition of miscanthus fibers into the PBAT matrix. These improvements were attributed to the strong reinforcing effect of miscanthus fibers. The polarity difference between the PBAT matrix and the miscanthus fibers leads to weak interaction between the phases in the resulting composites. This weak interaction was evidenced in the impact strength and tensile strength of the uncompatibilized PBAT composites. Therefore, maleic anhydride (MAH)‐grafted PBAT was prepared as compatibilizer by melt free radical grafting reaction. The MAH grafting on the PBAT was confirmed by Fourier transform infrared spectroscopy. The interfacial bonding between the miscanthus fibers and PBAT was improved with the addition of 5 wt % of MAH‐grafted PBAT (MAH‐g‐PBAT) compatibilizer. The improved interaction between the PBAT and the miscanthus fiber was corroborated with mechanical and morphological properties. The compatibilized PBAT composite with 40 wt % miscanthus fibers exhibited an average heat deflection temperature of 81 °C, notched Izod impact strength of 184 J/m, tensile strength of 19.4 MPa, and flexural strength of 22 MPa. From the scanning electron microscopy analysis, better interaction between the components can be observed in the compatibilized composites, which contribute to enhanced mechanical properties. Overall, the addition of miscanthus fibers into a PBAT matrix showed a significant benefit in terms of economic competitiveness and functional performances. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45448.

Making a Supertough Flame-Retardant Polylactide Composite through Reactive Blending with Ethylene-Acrylic Ester-Glycidyl Methacrylate Terpolymer and Addition of Aluminum Hypophosphite.

Biocompatible and biodegradable polylactide (PLA) composites with supertough mechanical property and sufficient flame retardancy were fabricated by employing a facile approach involving reactive blending of PLA and ethylene-acrylic ester-glycidyl methacrylate terpolymer (EGMA), with the addition of aluminum hypophosphite (AHP) as an effective flame retardant. In consideration of the balance between mechanical property and flame retardancy, the optimal formula was taking a PLA/EGMA 80/20 blend (supertough STPLA) as the matrix and adding 20 wt % of AHP (relative to the mass of STPLA) as the flame retardant, coded as STPLA/20AHP. The mechanical property test showed that for STPLA/20AHP the elongation at break was increased by about 22 times and the notched Izod impact strength was enhanced by approximately 11 times as compared to those for neat PLA. The flame-retardant property test showed that for STPLA/20AHP the limiting oxygen index value reached 26.6% and the UL-94 V0 rating test was passed. Thermogravimetric analysis, microscale combustion calorimetry, and cone calorimeter were further applied to reveal the thermal stability and combustion behaviors of STPLA/xAHP, respectively, where x indicated the mass content of AHP in percentage. The phase separation morphology, dispersion of AHP particles in STPLA matrix, and fracture surfaces and char residues after flame burning were examined by phase contrast optical microscopy and scanning electron microscopy, respectively, which helped comprehend the results obtained from the mechanical property and flame retardancy tests. The supertough STPLA/xAHP, with sufficient flame retardancy as prepared in this work, could have a potential for engineering applications.

Compatibilization and toughening of co-continuous ternary blends via partially wet droplets at the interface

This work reports that a partially wet phase can compatibilize and toughen a co-continuous PLA/PA11 blend. Four different polymers: PBS, PBAT, EMA and EMA-GMA are examined for their capacity to partially wet the PLA/PA11 interface in a melt-blending process. All the blends exhibit a partial wetting morphology, but offer very different compatibilization efficacies and toughening effects. EMA-GMA demonstrates the best compatibilization effect as it reduces the co-continuous thickness to 5–6 μm, which is about half that of the original binary PLA/PA11 blend, followed by EMA while PBS and PBAT result in the least changes in morphology and properties. Despite the enhanced compatibilization effect obtained with EMA-GMA, it is the self-assembled droplets of EMA at the PLA/PA11 interface which result in a major increase in the ductility of the blend with an elongation at break of 260% as compared to 4% for the binary blend. A substantial increase in the notched Izod impact strength is also achieved with partially wet droplets of EMA with a value of 73 J/m, a four-fold increase as compared to the impact strength of the pure PLA and the PLA/PA11 binary blend. This difference is attributed to the limited internal cavitation of the very fine droplets of EMA-GMA at the interface whereas the blends with partially wet EMA demonstrate significant interfacial cavitation after the impact fracture test. This work shows that self-assembled rubbery EMA droplets at a co-continuous PLA/PA11 interface combine to compatibilize the system, improve interfacial adhesion and interfacially cavitate through the continuous system upon fracture. The percolation of the stress field around these interfacially cavitated partially wet droplets results in the shear yielding of the matrix and a significant toughening effect ensues. These results indicate the potential of partially wet droplets to compatibilize and toughen co-continuous structures.

Exploring the Effect of Poly(propylene carbonate) Polyol in a Biobased Epoxy Interpenetrating Network.

Poly(propylene carbonate) (PPC) polyol derived from carbon dioxide has been used to make a tough biobased interpenetrating polymer network (IPN). PPC polyol (10, 20, and 30 phr) was added to an epoxy/poly(furfuryl alcohol) IPN, and the effect of PPC polyol on the tensile modulus, tensile strength, tensile toughness, and notched Izod impact strength was determined. Dynamic mechanical analysis (DMA) was used to investigate the effect of PPC polyol on the glass-transition temperature. Loss area (LA) as a characteristic of IPN damping properties was evaluated using DMA. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to obtain more information on the morphology of IPNs on the micro- and nanoscale. It was found that the incorporation of PPC polyol improved the notched Izod impact strength and tensile toughness up to 190 and 220%, respectively. The damping factor peak was broadened with the addition of PPC polyol, and the glass-transition temperature was decreased as the amount of PPC polyol increased. The IPN with 20 phr PPC polyol exhibited better damping properties than neat epoxy and the epoxy/PFA IPN. SEM and AFM images revealed that PPC polyol domains were dispersed in the epoxy phase with an average diameter of around 280 nm.

Biocomposites with Size-Fractionated Biocarbon: Influence of the Microstructure on Macroscopic Properties.

This study is an experimental investigation of using biocarbon as renewable carbonaceous filler for engineering-plastic-based blends. Poly(trimethylene terephthalate) (PTT) and poly(lactic acid) (PLA) combined with a terpolymer were selected as the blend matrix. Biocarbon with various particle size ranges was segregated and used as filler. Depending on the particle size and aspect ratio of the biocarbon used, the microstructure of the composite was found to change. Composites having a biocarbon particle size range of 20–75 μm resulted in a morphology showing better dispersion of the blend components when compared with composites containing other biocarbon particle size ranges. Furthermore, the addition of epoxy-based multifunctional chain extender was found to result in much finer morphologies having dispersed polymer particles of very small size. Impact strength increased significantly in composites that possessed such morphologies favoring high energy dissipation mechanisms. A maximum notched Izod impact strength of 85 J/m was achieved in certain composite formulations, which is impressive considering the inherent brittleness of PTT and PLA. From rheological observations, incorporation of biocarbon increased viscosity, but the shear-thinning behavior of the matrix was preserved. By increasing the injection mold temperature, fast crystallization of PTT was achieved, which increased the heat deflection temperature of composites to 80 °C. This study shows that composites with overall improvement in mechanical and thermal performance can be produced by selecting biocarbon with appropriate particle sizes and suitable processing aids and conditions, which all together control the morphology and crystallinity.

Fabrication and characterization properties of polypropylene/polycarbonate/clay nanocomposites prepared with twin-screw extruder

Abstract Polypropylene/polycarbonate (PP/PC) nanocomposites containing various proportions of the organically modified montmorillonite were prepared by extrusion and injection molding process. The morphology of PP/PC nanocomposites was characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The nanocomposites with 3 or 5 wt% of nanoclay (NC) show a uniform dispersion of the NC as pointed out by two different methods, TEM and XRD. It was shown that the morphology of dispersed phase (PC) is highly dependent on the content of minor phase, which was correlated with the balance of drop breakup and coalescence. The mechanical properties have been investigated by tensile test and Izod impact test. The virgin PP/PC samples showed a reduction in impact strength and elongation at break and up to 50% increase in Young’s modulus by increase in PP content comparing with the pure PP. Investigating the effect of NC and PC content on the mechanical behavior of PP/PC nanocomposites showed increased Young’s modulus and decreased impact strength with increasing PC and NC loading. An obvious ductile to brittle behavior transition at a high content of PC or NC was supported by notched Izod impact strength experiments and SEM results.

Effect of the matrix plasticization behavior on mechanical properties of PVC/ABS blends

Abstract Acrylonitrile-butadiene-styrene (ABS) grafted copolymer prepared by emulsion polymerization was used to modify different molecular weight poly (vinyl chloride) (PVC) resins. The effects of the molecular weight of the PVC resins on dynamic mechanical analyses (DMA) of PVC/ABS blends and matrix plasticizing behavior on the impact mechanical properties and the morphology were investigated. The tan δ peaks of PVC/ABS blends occurred at the same temperature obtained by DMA, indicating that miscibility of PVC/ABS blends was independent of the molecular weight of PVC. The notched Izod impact test results indicated that the amount of polybutadiene (PB) rubber needed for the brittle-ductile transition (BDT) increases together with the molecular weight of PVC when milled at 165°C. Increasing the operation temperature and adding the plasticizer dioctyl phthalate (DOP) could change the matrix plasticizing extent and the BDT. At a milling temperature of 165°C, the BDT was reached only with 3.6 wt% PB when DOP was added, in contrast to the addition of 7.2 wt% PB in the absence of DOP. The morphology of different plasticized degree of PVC/ABS blends was studied by transmission electron microscopy (TEM) showing that the PVC-1/ABS blends milled at 165°C showed a larger unstained area than the other series of PVC blends.