Synthesis,characterization of layered double hydroxide‐poly(methylmethacrylate) graft copolymers via activators regenerated by electron transfer for atom transfer radical polymerization and its effect on the performance of poly(lactic acid)

Layered double hydroxide‐poly(methylmethacrylate) (LDH‐PMMA) graft copolymers were prepared via activators regenerated by electron transfer for atom transfer radical polymerization. The results showed that the hydrophobicity of LDH‐PMMA was improved by the incorporation of hydrophilic groups. Moreover, poly(lactic acid) (PLA)/LDH‐PMMA nanocomposites were prepared by melt blending to enhance the performances of PLA. The crystallization and mechanical properties of the PLA/LDH‐PMMA nanocomposites were studied by differential scanning calorimetry, tensile testing, and polarized optical microscopy, respectively. Results of mechanical testing showed that the tensile strength, elongation at break, and impact strength of PLA/LDH‐PMMA nanocomposites were increased by 5.64%, 37.95%, and 49.70%, respectively, compared with PLA. The differential scanning calorimetry results indicated that LDH‐PMMA eliminated the cold crystallization of PLA matrix and improved the crystallinity of PLA by 37.26%. The polarized optical microscopy of PLA/LDH‐PMMA nanocomposites demonstrated that LDH‐PMMA increased the crystallization rate of PLA. It was also found that the rheological behaviors of the PLA nanocomposites were significantly enhanced. Based on these results, a new choice for modified LDHs was provided and used as a nucleating agent to improve the properties of PLA.     

Preparation and characterization of phosphorylated graphene oxide grafted with poly(L‐lactide) and its effect on the crystallization,rheological behavior,and performance of poly (lactic acid)

Phosphorylated graphene oxide (PGO) was prepared by using phosphoric acid as functional reagent, and PGO was grafted with poly(L‐lactide) (PGO‐PLLA) by ring‐opening polymerization of L‐lactide as monomer under nano‐ZnO catalyst. The results of the orthogonal analysis showed the optimum reaction conditions to be as follows: the reaction temperature of 170°C, reaction time of 14 hours, the mass ratio of PGO of 10 wt%, and the mass of nano‐ZnO of 1 wt%. PGO‐PLLA was characterized by fourier transform infrared spectroscopy, gel permeation chromatography, and X‐ray photoelectron spectroscopy, which demonstrated that the PLLA molecular chains were successfully grafted onto the surface of PGO. Poly (lactic acid)/PGO‐PLLA nanocomposites (PLA/PGO‐PLLA) were prepared by melt intercalation. Mechanical test and fracture scanning electron microscopy showed that PGO‐PLLA (0.3 wt%) improved impact strength of PLA by 52.19%, which resulted in ductile fractures surface of PLA/PGO‐PLLA. Microcalorimetry and thermal degradation kinetics proved that PGO‐PLLA improved the thermal stability of PLA. Polarized optical microscopy and differential scanning calorimetry confirmed that PGO‐PLLA increased crystallization rate and spherulite kernel density of PLA, and crystallinity of PLA/PGO‐PLLA reached to 22.05%. Rheological behavior proved that PGO‐PLLA increased the self‐lubricity of PLA. Enzymatic degradation results illustrated that PGO‐PLLA had some inhibition for the biodegradability of PLA based nanocomposites.     

Effect of processing method on the structure and properties of HDPE/EAA/LDHs nanocomposites

High-density polyethylene/ethylene–acrylic acid copolymer/layered double hydroxides (LDHs) nanocomposites were prepared by the methods of one-step extrusion and twice extrusion in this paper. The structure and properties of the nanocomposites were also studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), differential scanning calorimetry (DSC), thermogravimetry (TG), and the cone calorimeter. The results of XRD, SEM, and TEM analyses demonstrated that the method of twice extrusion gave the LDHs a higher level of exfoliation within the matrix compared with the method of one-step extrusion. The DSC and TG analysis revealed that the crystalline property and the thermal stability of the nanocomposites could be improved by the method of secondary extrusion. The cone calorimeter test showed that the method of secondary extrusion could improve the flame retardant property of the nanocomposites to some degree.     

Synthesis,characterization, and thermal stability of poly (lactic acid)/zinc oxide pillared organic saponite nanocomposites via ring‐opening polymerization of d,l‐lactide

Poly (lactic acid) (PLA) was synthesized using d , l ‐lactide monomer and zinc oxide (ZnO) pillared organic saponite as the green catalyst, through ring‐opening polymerization. The effects of stoichiometry of catalyst and polymerization conditions on molecular weight of PLA were evaluated by orthogonal experiment. The optimum polymerization parameters were: 0.5 wt% ZnO pillared organic saponite and reaction conditions of 170°C for 20 hr. Fourier transform infrared spectroscopy and ¹H nuclear magnetic resonance spectroscopy confirmed the PLA structure. Gel permeation chromatography showed that the average molecular weight of PLA was 48,442 g/mol, and its polydispersity index was 1.875. Differential scanning calorimetry, X‐ray diffraction, and polarized optical microscopy showed that ZnO pillared organic saponite improved the crystallinity of PLA. Thermal gravimetric analysis showed improved thermal stability of PLA because of ZnO pillared organic saponite. Thermal decomposition kinetics of PLA/ZnO pillared organic saponite nanocomposites was also studied. The activation energies (E_a) for thermal degradation of PLA and PLA/ZnO pillared organic saponite nanocomposites were evaluated by the Kissinger and Ozawa methods, which demonstrated that ZnO pillared organic saponite enhanced E_a of thermal degradation of PLA and significantly improved its thermal stability. Copyright © 2015 John Wiley & Sons, Ltd.     

Synthesis and physical properties of new layered double hydroxides based on ionic liquids: Application to a polylactide matrix

Ionic liquids based on tetraalkylphosphonium salts combined with different anions (decanoate and dodecylsulfonate) have been used as intercalating agents of layered double hydroxides (LDHs) by ion exchange. The synthesized phosphonium-treated LDHs display a dramatically improved thermal degradation and a significant increase in the interlayer distance as confirmed by thermogravimetric analysis (TGA) and X-ray Diffraction (XRD), respectively. To highlight the effect of thermostable ionic liquids, a very low amount of LDHs has been introduced within a polylactide (PLA) matrix and PLA/LDHs nanocomposites have been processed in melt by twin-screw extrusion. Then, transmission electron microscopy (TEM) analysis has been used to investigate the influence of ILs on the different morphologies of these nanocomposites. Even though the thermal stability of PLA matrix decreased, an excellent stiffness-toughness compromise has been obtained.     

Polylactide/exfoliated graphite nanocomposites with enhanced thermal stability,mechanical modulus,and electrical conductivity

We have prepared a series of polylactide/exfoliated graphite (PLA/EG) nanocomposites by melt‐compounding and investigated their morphology, structures, thermal stability, mechanical, and electrical properties. For PLA/EG nanocomposites, EG was prepared by the acid treatment and following rapid thermal expansion of micron‐sized crystalline natural graphite (NG), and it was characterized to be composed of disordered graphite nanoplatelets. It was revealed that graphite nanoplatelets of PLA/EG nanocomposites were dispersed homogeneously in the PLA matrix without forming the crystalline aggregates, unlike PLA/NG composites. Thermal degradation temperatures of PLA/EG nanocomposites increased substantially with the increment of EG content up to ～3 wt %, whereas those of PLA/NG composites remained constant regardless of the NG content. For instance, thermal degradation temperature of PLA/EG nanocomposite with only 0.5 wt % EG was improved by ～10 K over PLA homopolymer. Young's moduli of PLA/EG nanocomposites increased noticeably with the increment of EG content up to ～3 wt %, compared with PLA/NG composites. The percolation threshold for electrical conduction of PLA/EG nanocomposites was found to be at 3–5 wt % EG, which is far lower graphite content than that (10–15 wt % NG) of PLA/NG composites. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 850–858, 2010     

聚乳酸/氧化锌柱撑皂石纳米复合材料制备与性能及结构表征

通过微波水解法制备了ZnO柱撑皂石,并以其为加工助剂制备了聚乳酸(PLA)/ZnO柱撑皂石纳米复合材料.通过X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、对ZnO柱撑皂石及PLA/ZnO柱撑皂石纳米复合材料的结构进行了表征,并对其力学性能和热稳定性能进行了测试.微观结构分析表明,ZnO柱撑皂石呈现剥离状,并均匀分散在PLA基质中.力学性能研究表明0.3%ZnO柱撑皂石的加入有助于改善PLA复合材料的断裂伸长率.SEM分析表明PLA复合材料的断面发生明显改变,表现良好韧性;DSC结果显示纳米ZnO柱撑皂石可以降低复合材料的玻璃化转变温度、结晶温度,有助于提高PLA复合材料的结晶度,与XRD分析相吻合;热重分析表明ZnO柱撑皂石可以提高PLA复合材料的热稳定性.测试结果表明,ZnO柱撑皂石在PLA基质中起到了异相成核的作用,促进了PLA基质的结晶.     

Poly l-lactide-layered double hydroxide nanocomposites via in situ polymerization of l-lactide

The use of clay nanofillers offers a potential route to improved barrier properties in polylactide films. Magnesium-aluminium layered double hydroxides (LDHs) are interesting in this respect and we therefore explored synthesis of PLA-LDH nanocomposites by ring-opening polymerization. This method is attractive because it should ensure good dispersion of LDH in the polymer. The effect of adding either LDH carbonate (LDH-CO₃) or laurate-modified LDH (LDH-C₁₂) was investigated. X-ray diffraction, scanning electron microscopy, and transmission electron microscopy revealed that exfoliated nanocomposites were obtained when using LDH-C₁₂ but that LDH-CO₃ gave a partly phase-separated morphology. Thermogravimetric analysis showed that PLA-LDH combinations exhibited higher degradation onset temperatures and differential scanning calorimetry confirmed that LDHs can act as nucleating agents. However, PLA molecular weight was significantly reduced when in-situ polymerization was conducted in the presence of the LDHs and we suggest that chain termination via LDH surface hydroxyl groups and/or metal-catalyzed degradation could be responsible.     

Structure‐property relationship,rheological behavior,and thermal degradability of poly(lactic acid)/fulvic acid amide composites

Fulvic acid amide (FAA) was synthesized with fulvic acid (FA) and urea. The structure of FAA was characterized by X‐ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. Poly(lactic acid)/fulvic acid amide (PLA/FAA) composites were prepared by melt blending and compression molding. The nucleation effect of FAA on PLA was investigated by differential scanning calorimetry and polarized optical microscopy. Structure‐property relationship of PLA/FAA composites showed that FAA accelerated crystallization rate of PLA and improved toughness of PLA. Rotational rheological behavior of PLA/FAA composites showed that FAA increased the storage modulus of PLA. Capillary rheological analysis showed that the apparent viscosities of PLA composites were highly increased after the introduction of the FAA nucleating agent. Moreover, thermogravimetric analysis demonstrated that thermal degradability of PLA/FAA composites has been increased significantly compared with the neat PLA.     

Preparation and Characterization of Intercalated Polymethacrylamide/Na‐Montmorillonite Nanocomposites

Polymethacrylamide/Na‐montmorillonite nanocomposites have been prepared by free‐radical polymerization. All the nanocomposites were characterized by Fourier transform infrared spectroscopy, X‐ray diffraction, scanning electron microscopy, thermogravimetric analysis, and differential thermal analysis. The thermal properties of nanocomposites are notably improved by the presence of the montmorillonite layers in comparison with pure polymethacrylamide. X‐ray diffraction and scanning electron microscopy confirmed that polymethacrylamide could be easily inserted between the layers of Na‐montmorillonite to form intercalated nanocomposites, and significantly large d‐spacing expansions from 1.19 to 2.93 nm of the nanocomposites. Adsorptive properties of nanocomposites were also investigated.     

A method for simultaneously improving the flame retardancy and toughness of PLA

In order to modify the brittleness and flame retardant properties of poly(lactic acid) (PLA), a series of flame retardant toughened PLA composites were prepared using poly(ethylene glycol) 6000 (PEG6000) as a toughening and charring agent together with ammonium polyphosphate (APP) as an acid source and blowing agent. The fire and thermal behavior of PLA/PEG/APP composites was evaluated by limiting oxygen index (LOI), UL‐94, cone calorimeter, and thermogravimetric analysis (TGA). The results showed that the PLA/PEG/APP system had good charring ability and could improve the flame retardancy of PLA. When the content of APP in the composites was more than 5 wt%, all samples could reach UL‐94 V‐0 rating. The results of mechanical property tests demonstrated that the brittleness of PLA was also improved after blended with PEG6000. All the PLA/PEG/APP composites with an APP content of less than 10 wt% showed an obvious neck and fracture behavior, that is, the tensile behavior of PLA was changed from brittle to ductile. Copyright © 2010 John Wiley & Sons, Ltd.     

乳液聚合法制备聚苯乙烯/Mg-Al层状双氢氧化物纳米复合材料

采用乳液聚合法制备阻燃性聚苯乙烯MgAl层状双氢氧化物(LDHs)纳米复合材料.通过对不同合成条件下复合材料的XRD谱,讨论了纳米复合材料的形成过程;经SEM图证实了LDHs是以剥离的纳米级层片分散在基体中的;TG和DSC谱图揭示了LDHs纳米层板可有效提高PS的热稳定性,并可使PS的玻璃化转化温度明显提高;当层状双氢氧化物在插层复合材料中含量为14.92%时,纳米复合材料的氧指数可达23.5%,其用量比在PS中直接添加纳米LDHs时要少约一倍.文中还分析了纳米复合材料的形成过程.     

Electrospun hyperbranched polylactic acid–modified cellulose nanocrystals/polylactic acid for shape memory membranes with high mechanical properties

The polylactic acid (PLA) nanofiber membranes reinforced with hyperbranched PLA‐modified cellulose nanocrystals (H‐PLA‐CNCs) were prepared by electrospinning. The H‐PLA‐CNCs and the nanofiber membranes were researched by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), and dynamic mechanical analysis (DMA). The outcomes embodied that the cellulose nanocrystals (CNCs) could be successfully improved by the hyperbranched PLA, which would offer powerful CNCs/matrix interfacial adhesion. Thus, the mechanical and shape memory properties of PLA can be improved by adding the H‐PLA‐CNCs. In particular, when the addition of H‐PLA‐CNCs was 7 wt%, the tensile strength and an ultimate strain of PLA composite nanofiber membranes was 15.56 MPa and 25%, which was 228% and 72.4% higher than that of neat PLA, respectively. In addition, the shape recovery rate of the PLA/5 wt% H‐PLA‐CNCs composite nanofiber membrane was 93%, which was 37% higher than that of neat PLA. We expected that this present study would provide unremitting efforts for the development of more effective approaches to prepare biology basic shape memory membranes with high mechanical properties.     

Thermal properties of poly(lactic acid)/organo-montmorillonite nanocomposites

Poly(lactic acid)/organo-montmorillonite nanocomposites were prepared by melt intercalation technique. Maleic anhydride-grafted ethylene propylene rubber (EPMgMA) was added into the PLA/OMMT in order to improve the compatibility and toughness of the nanocomposites. The samples were prepared by single screw extrusion followed by compression molding. The effect of OMMT and EPMgMA on the thermal properties of PLA was studied. The thermal properties of the PLA/OMMT nanocomposites have been investigated by using differential scanning calorimeter (DSC) and thermo-gravimetry analyzer (TG). The melting temperature (T _m), glass transition temperature (T _g), crystallization temperature (T _c), degree of crystallinity (χ_c), and thermal stability of the PLA/OMMT nanocomposites have been studied. It was found that the thermal properties of PLA were greatly influenced by the addition of OMMT and EPMgMA.     

Effects of clay‐modifying agents on the morphology and properties of poly(methyl methacrylate)/clay nanocomposites synthesized via γ‐ray irradiation polymerization

Via γ‐ray irradiation polymerization, poly(methyl methacrylate) (PMMA)/clay nanocomposites were successfully prepared with reactive modified clay and nonreactive clay. With reactive modified clay, exfoliated PMMA/clay nanocomposites were obtained, and with nonreactive clay, intercalated PMMA/clay nanocomposites were obtained. Both results were confirmed by X‐ray diffraction and high‐resolution transmission electron microscopy. PMMA extracted from PMMA/clay nanocomposites synthesized by γ‐ray irradiation had higher molecular weights and narrow molecular weight distributions. The enhanced thermal properties of the PMMA/clay nanocomposites were characterized by thermogravimetric analysis and differential scanning calorimetry. The improved mechanical properties of PMMA/clay were characterized by dynamic mechanical analysis. In particular, the enhancement of the thermal properties of the PMMA/clay nanocomposites with reactive modified clay was much more obvious than that of the PMMA/clay nanocomposites with nonreactive clay. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3218–3226, 2003     

Melt‐blending of unmodified and modified cellulose nanocrystals with reduced graphene oxide into PLA matrix for biomedical application

In this article, we successfully fabricated the bionanocomposites using cellulose nanocrystals (CNCs) and reduced graphene oxide (rGO) reinforced into biodegradable polylactic acid (PLA) matrix through melt‐mixing method. Due to the affinity difference between hydrophilic CNC and hydrophobic PLA, the surface modification of CNC was employed using quaternary ammonium salts (CTAB) as a surfactant. The nanocomposites were developed using different blend ratios of CNC/modified CNC (1, 2, and 3) wt% and (0.5 wt%) rGO into the polymer matrix. The morphology of CNC, q‐CNC (modified CNC), and nanocomposites were inspected by atomic force microscopy (AFM) and field emission scanning electron microscopy (FESEM). It is demonstrated from tensile tests that, the nanocomposite with 1 wt% CNC and rGO showed maximum tensile strength compared with PLA and its nanocomposites. Moreover, the nanocomposite with 1 wt% CNC and rGO was also having maximum thermal stability. From cytotoxicity evaluation, it is observed that all the nanocomposites are nontoxic and cytocompatible to HEK293 cells. In addition to this, the nanocomposite with q‐CNC showed enhanced barrier properties compared with PLA and PLA/CNC/rGO nanocomposite. The results obtained from different characterizations showed that the incorporation of surfactant onto CNC improved the dispersion in PLA but at the same time deteriorated the PLA matrix.     

The influence of multiple modified MMT on the thermal and fire behavior of poly (lactic acid) nanocomposites

This work reported the preparation and physical properties of biodegradable nanocomposites fabricated using polylactic acid (PLA) and multiple organic modified montmorillonite (MMT). In order to improve the chemical compatibility between PLA and Na‐MMT, the surface of Na‐MMT was first organically modified by cetyl trimethyl ammonium bromide (CTAB) and resorcinol bis(diphenyl phosphate) (RDP) using ion‐exchange and adsorption technique. Both Fourier transform infrared and X‐ray diffraction (XRD) results indicated that CTAB and RDP molecules were intercalated into the galleries of MMT sheets to enlarge the interlayer spacing. Then, the PLA/MMT nanocomposites were prepared by a simple melt‐blending method. The XRD and TEM results of the nanocomposites indicated that the PLA polymer chains inserted into the galleries of co‐modified MMT (C‐MMT) and contained disorderedly intercalated layered silicate layers within a PLA matrix. The C‐MMT nanolayers were homogenously dispersed in PLA matrix, resulting in various property enhancement. The fabricated PLA/C‐MMT nanocomposites with 5.0 wt% addition showed significant enhancements (176%) in the storage modulus compared to that of neat PLA. The thermal stability and fire resistance were also remarkably improved. These improvements are probably because of both the physical barrier effect of the MMT nanosheets and charring effect of the C‐MMT. Copyright © 2015 John Wiley & Sons, Ltd.     

Melt compounding of polylactide/organoclay: Structure and properties of nanocomposites

A Brabender mixer was used to deagglomerate and disperse organomodified montmorillonite Cloisite® 30B (3 wt %) in polylactide (PLA) matrix to obtain nanocomposite systems. The influence of compounding conditions such as blending time (6.5, 10, 20, and 30 min) and compression molding on the nanostructure of nanocomposites was investigated. Molecular weight changes of the PLA matrices induced by melt compounding were determined. Good rheological behavior of the PLA during melt blending with Cloisite® 30B was observed. Prolongation of the blending process improved homogenization of the nanocomposites with the formation of more intercalated and exfoliated structures as revealed by transmission electron microscopy (TEM) and X‐ray analysis. Some orientation of the silicate nanoplatelets induced by compression molding of the nanocomposites was revealed by TEM. It was found that an increase of dispersion degree of the silicate layers modified pronouncedly the physical properties of nanocomposites through an increase of thermal stability as revealed by the thermogravimetric analysis, a decrease of crystallizability of the PLA matrix during melt‐crystallization and upon heating from the glassy, amorphous state. Rheological properties of the nanocomposites determined during dynamic frequency sweep appeared to be very sensitive to the nanostructure evolution. Moreover, the scanning electron microscopy and light microscopy investigations showed the presence of the micron‐size inorganic contaminations in the nanocomposites originating from organoclay Cloisite® 30B. These inclusions were resistive to deagglomeration during melt processing. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 3392–3405, 2006     

Preparation and characterization of benzoyl‐hydrazide‐derivatized poly(lactic acid) and γ‐cyclodextrin inclusion complex and its effect on the performance of poly(lactic acid)

A nucleating agent, benzyl‐hydrazide‐derivatized poly(lactic acid) (PLA) and γ‐cyclodextrin inclusion complex (PLA‐IC‐BH), was synthesized through a series of reactions. Poly(lactic acid) and γ‐cyclodextrin inclusion complex (PLA‐IC) was first obtained by ultrasonic co‐precipitation, which was then subjected to carboxylation, acylation, and amidation using benzoyl hydrazine and thionyl chloride. The composition and structure of PLA‐IC‐BH was confirmed by ¹H nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, and X‐ray diffraction. PLA/PLA‐IC‐BH composites were prepared by melt blending and a hot‐press forming process. Mechanical properties, thermal stabilities, and crystallization behaviors of PLA/PLA‐IC‐BH samples were investigated by thermogravimetric analysis, differential scanning calorimetry (DSC), polarized optical microscopy (POM), rheological analysis, and so on. Mechanical testing and thermogravimetric analysis showed that the tensile strengths, impact properties, and thermal stabilities of PLA/PLA‐IC‐BH composites were improved significantly compared to pure PLA and PLA/PLA‐IC. DSC results showed that crystallinity of PLA was increased from 5.17% to 38.93% after introduction of PLA‐IC‐BH. POM results showed that PLA‐IC‐BH acted as a nucleating agent for PLA and enhanced its crystallization rate. Rotational rheological behaviors of PLA/PLA‐IC‐BH demonstrated that incorporation of PLA‐IC‐BH increased the rigidity of the network structure of the PLA matrix. Compared to those of PLA, the maximum torque and apparent viscosity of PLA/PLA‐IC‐BH composites were increased by 55.56% and 25.59%, respectively. Copyright © 2017 John Wiley & Sons, Ltd.     

Influence of SEBS-g-MA on morphology, mechanical, and thermal properties of PA6/PP/organoclay nanocomposites

Polyamide 6/polypropylene (PA6/PP = 70/30 parts) blends containing 4 phr (parts per hundred resin) of organically modified clay (organoclay) toughened with maleated styrene-ethylene-butylene-styrene (SEBS-g-MA) were prepared by melt compounding using co-rotating twin-screw extruder followed by injection molding. X-ray diffraction (XRD) and transmission electron microscope (TEM) were used to characterize the structure of the nanocomposites. The mechanical properties of the nanocomposites were determined by tensile, flexural, and notched Izod impact tests. The single edge notch three point bending test was used to evaluate the fracture toughness of SEBS-g-MA toughened PA6/PP nanocomposites. Thermal properties were studied by using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). XRD and TEM results indicated the formation of the exfoliated structure for the PA6/PP/organoclay nanocomposites with and without SEBS-g-MA. With the exception of stiffness and strength, the addition of SEBS-g-MA into the PA6/PP/organoclay nanocomposites increased ductility, impact strength and fracture toughness. The elongation at break and fracture toughness of PA6/PP blends and nanocomposites were increased with increasing the testing speed, whereas tensile strength was decreased. The increase in ductility and fracture toughness at high testing speed could be attributed to the thermal blunting mechanism in front of crack tip. DSC results revealed that the presence of SEBS-g-MA had negligible effect on the melting and crystallization behavior of the PA6/PP/organoclay nanocomposites. TGA results showed that the incorporation of SEBS-g-MA increased the thermal stability of the nanocomposite.