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1.
Styrene-ethylene-butylene-styrene block copolymer (SEBS)/clay nanocomposites were prepared via a melt mixing technique. Various amounts of two types of compatibilizers, maleated styrene-ethylene-butylene-styrene block copolymer (SEBS-g-MA) and maleated polypropylene (PP-g-MA), were incorporated to improve the dispersion of 5 wt% commercial organoclay (denoted as 20A), respectively. The X-ray diffraction (XRD) and transmission electron microscope (TEM) experimental results revealed that nanocomposites were achieved in all cases. The Fourier Transform infrared spectra and dynamic properties indicated a higher interaction for styrene blocks with clay moiety. The transmittance for the nanocomposites slightly decreased with increasing SEBS-g-MA dosage, which presented an opposing trend compared with the PP-g-MA case. The PP-g-MA compatibilized system conferred higher mechanical properties than the SEBS-g-MA compatibilized system, even though a higher dosage of SEBS-g-MA was beneficial in further expanding the interlayer spacing of the clay. The unexpected results suggested matrix properties and interfacial phase were the major factors in attaining the best performance in terms of mechanical properties for the investigated system.  相似文献   

2.
Thermoplastic elastomers (TPEs) based on new generation ultrahigh molecular weight styrene‐ethylene‐butylene‐styrene (SEBS) and thermoplastic polyurethane (TPU) are developed and characterized especially for automotive applications. Influence of maleic anhydride grafted styrene‐ethylene‐butylene‐styrene (SEBS‐g‐MA) and maleic anhydride grafted ethylene propylene rubber (EPM‐g‐MA) as compatibilizers has been explored and compared on the blends of SEBS/TPU (60:40). The amount of compatibilizers was varied from 0 to 10 phr. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) studies revealed the dramatic changes from a nonuniform to finer and uniform dispersed phase morphology. This was reflected in various mechanical properties. SEBS‐g‐MA modified blends showed higher tensile strength. EPM‐g‐MA modified blends also displayed considerable improvement. Elongation at break (EB) was doubled for the entire compatibilized blends. Fourier‐transform infrared spectrometry (FTIR) confirmed the chemical changes in the blends brought about by the interactions between blend components and compatibilizers. Both SEBS‐g‐MA and EPM‐g‐MA had more or less similar effects in dynamic mechanical properties of the blends. Additionally, melt rheological studies have also been pursued through a rubber process analyzer (RPA) to get a better insight.  相似文献   

3.
The paper presents differential scanning calorimetry and electron microscopy of the fractionated crystallization and polydispersity of the dispersed PA6 phase in compatibilized LDPE/PA6 75/25 w/w blends. The compatibilizers used were (i) an acrylic acid functionalized polyethylene, Escor 5001 (EAA); (ii) an ethylene-glycidylmethacrylate copolymer, Lotader GMA AX8840 (EGMA); (iii) a polystyrene-poly(ethylene-butylene)-polystyrene triblock copolymer comprising 2 wt.% maleic anhydride grafts, Kraton FG 1901X (SEBS-g-MA). The compatibilizer SEBS-g-MA has the strongest reduction effect upon the size of PA-6 droplets. Its implementation provides the best fractionated crystallization. The fractionated crystallization has not been observed for the blend compatibilized with EGMA. The results show that the degree of compatibilization could be evaluated qualitatively by the progress of the fractionated crystallization. So, the three compatibilizers could be rated according to their effectiveness as follows: SEBS-g-MA > EAA > EGMA. The self-nucleation experiments have demonstrated that the lack of active nuclei in the finely dispersed PA6 droplets is the determining factor for the fractionated crystallization at high supercooling, and not the considered absolute particle size. The measurement of the Vickers microhardness of the compatibilized blends confirms that the compatibilizing activity of SEBS-g-MA and EAA is stronger than that of EGMA.  相似文献   

4.
The calorimetric characteristics, the flammability, the thermal stability and the microhardness of polyethylene high density/clay nanocomposites (HDPE/clay) have been studied by differential scanning calorimetry, thermogravimetry, determination of limiting oxygen index and microhardness tests. The nanocomposites have been compatibilized by ethylene–acrylic acid copolymer (EAA), acrylic acid grafted HDPE (HDAA) and maleic anhydride grafted HDPE (HDMA). The clay was montmorillonite Cloisite 15A. The influence of the presence and the type of the compatibilizers on the properties of the nanocomposites has been evaluated. The results have shown that the thermal stability, the reduction of the flammability and the microhardness of HDPE/clay nanocomposites, compatibilized by HDAA and HDMA are higher than those for nanocomposite compatibilized by EAA. Moreover, the presence and the type of compatibilizer have negligible effect on the characteristics of the HDPE phase transitions. These results have been interpreted by the better clay dispersion and higher level of clay exfoliation in the presence of compatibilizers HDAA and HDMA, than those in the presence of EAA compatibilizer.  相似文献   

5.
In the present study, a series of iPP/SiO2 nanocomposites, containing 1, 2.5, 5, 7.5, 10 and 15 wt% SiO2 nanoparticles, were prepared by melt mixing in a twin screw co-rotating extruder. Poly(propylene-g-maleic anhydride) copolymer (PP-g-MA) containing 0.6 wt% maleic anhydride content was added to all nanocomposites at three different concentrations, 1, 2.5 and 5 wt%, based on silica content. Mechanical properties such as tensile strength at break and Young’s modulus were found to increase and to be mainly affected by the content of silica nanoparticles as well as by the copolymer content. For the tensile strength at break as well as for yield point, a maximum was observed, corresponding to the samples containing 2.5-5 wt% SiO2. At higher concentrations, large nanosilica agglomerates are formed that have as a result a decrease in tensile strength. Young’s modulus increases almost linearly on the addition of SiO2, and takes values up to 60% higher than that of neat iPP. Higher concentrations of PP-g-MA resulted in a further enhancement of mechanical properties due to silica agglomerate reduction. This finding was verified from SEM and TEM micrographs. Evidently the surface silica hydroxyl groups of SiO2 nanoparticles react with maleic anhydride groups of PP-g-MA and lead to a finer dispersion of individual SiO2 nanoparticles in the iPP matrix. The enhanced adhesion in the interface of the two materials, as a result of the mentioned reaction, has been studied and proved by using several equations. The increased Vicat point of all nanocomposites, by increasing the PP-g-MA content, can also be mentioned as a positive effect.  相似文献   

6.
β-Nucleated polypropylene (PP), non-compatibilized and compatibilized β-nucleated PP/recycled poly(ethylene terephthalate) (r-PET) blends were prepared on a twin-screw extruder. The compatibilizers were maleic anhydride grafted PP (PP-g-MA), glycidyl methacrylate grafted PP (PP-g-GMA), maleic anhydride grafted polyethylene-octene (POE-g-MA) and polyethylene-vinyl acetate (EVA-g-MA) elastomers. Effects of r-PET content, compatibilizer type and content, pre-melting temperature and time on the non-isothermal crystallization and melting behavior, and polymorphism of PP in the blends were investigated by differential scanning calorimeter (DSC). DSC results show that the crystallization temperature of PP crystallized predominantly in β-modification was higher than that of neat PP. In the non-compatibilized blend, PP matrix crystallized mainly in α-modification even if r-PET content was only 10 wt%. However, PP-g-MA compatibilization made PP matrix crystallize mainly in β-modification, but PP-g-GMA, POE-g-MA and EVA-g-MA did not improve the β-modification content distinctly. The α-crystal melting peak temperature of PP decreased with increasing pre-melting temperature, but r-PET content, compatibilizer type and content as well as pre-melting time had no obvious effect on the melting temperature of PP. The increase in PP-g-MA content, pre-melting temperature and time was benefit for the formation of β-modification. It is suggested that the β-nucleating agent is encapsulated or dissolved in polar r-PET in β-nucleated PP/r-PET blend, addition of PP-g-MA to the non-compatibilized blend resulted in transferring β-nucleating agent from r-PET phase into PP phase, the increase in PP-g-MA content, melting temperature and time was benefit for transferring β-nucleating agent from r-PET phase into PP phase. The non-isothermal crystallization kinetics of PP in the blends were evaluated by Mo’s method.  相似文献   

7.
纳米CaCO_3/相容剂/PP中的界面相互作用研究   总被引:1,自引:0,他引:1  
采用不同相容剂(PP-g-MAH、POE-g-MAH和EVA-g-MAH)制备了不同界面相互作用的纳米CaCO3(CC)/相容剂/PP体系,研究了相容剂/PP和相容剂/CC界面相互作用对PP/CC的结晶形态、结晶行为、熔融特性和力学性能的影响.观察到PP/CC界面相互作用提高PP结晶温度和PP/CC的模量和冲击强度,但降低了屈服强度.相容剂/CC界面相互作用进一步提高了PP/CC的结晶温度.PP/相容剂界面相互作用取决于PP与相容剂相容性.PP/PP-g-MAH相容性高有利于提高PP/CC的异相成核作用和PP/CC屈服强度和模量,但降低冲击强度.PP/POE-g-MAH部分相容对相容剂/CC界面的异相成核作用、PP/CC屈服强度和模量影响不大,可明显提高冲击强度.但PP/EVA-g-MAH不相容导致PP/CC冲击强度明显降低.  相似文献   

8.
考察了氢化苯乙烯-丁二烯嵌段共聚弹性体(SEBS)及其马来酸酐接枝共聚物(SEBS-g-MA)增韧聚苯醚(PPO)体系。DSC谱图显示,PPO与SEBS的共混物仅有一个Tg,两者完全相容;PPO与SEBS-g-MA的共混物存在两个Tg,只能达到部分相容。力学性能研究表明,在PPO/SEBS体系中,基体中分散相SEBS的相界面模糊,无法引发基体银纹和剪切屈服,增韧PPO的效果有限;而部分相容的PPO/SEBS-g-MA共混物显示了增韧剂良好的相界面引发基体银纹和剪切屈服的作用,其缺口冲击强度在SEBS-g-MA质量分数为20%时达到1260J/m的超韧性。亚微相态显示,SEBS在PPO中呈现条形分散相的"海岛"结构;而SEBS-g-MA在基体中呈现网络结构。流变性能研究显示,PPO/SEBS共混物的表观粘度均高于PPO,并随SEBS的含量增加而变大;而PPO/SEBS-g-MA则完全相反。  相似文献   

9.
《European Polymer Journal》2007,43(5):1660-1671
The physical and thermal properties of nanoclay filled nylon 6 (nano-nylon 6) blended with poly(acrylonitrile–butadiene–styrene)terpolymers (ABS) were investigated using metallocene polyethylene grafted maleic anhydride (POE-g-MA) or polybutadiene grafted maleic anhydride (PB-g-MA) as a compatibilizer. Cooling conditions significantly affected the crystalline structure of nano-nylon 6. No clear effect of both compatibilizers on the dispersion of clay has been observed via transmission electron microscope analysis. Through morphology observation, the ABS particle sizes tended to decrease with the addition of compatibilizers, especially in PB-g-MA cases, suggesting a good interfacial bonding between nano-nylon 6 matrix and ABS dispersed phase. Non-isothermal crystallization results indicated that the crystallization temperatures slightly changed with increasing content of compatibilizers. In addition, melting behaviors with different crystal forms varied widely with cooling conditions. The crystallization kinetics under isothermal conditions reflected that introduced compatibilizers impeded the growth rate, especially for PB-g-MA compatibilized system.  相似文献   

10.
Nanocomposites based on low density polyethylene, containing of 3 or 6 wt.% of organo-modified montmorillonite nanoclay (MMT-ODA) and maleic anhydride grafted low density polyethylene as a compatibilizer were prepared by melt mixing and characterized. Exfoliation of silicate layers was achieved, as confirmed by X-ray diffraction and transmission electron microscopy. The compatibilized nanocomposites exhibit improved thermal stability in air as compared to neat polyethylene and nonexfoliated MMT-ODA composite. The crystallinity and crystallization kinetics of polyethylene matrix is not affected significantly by the presence of MMT-ODA clay. Drawability of the compatibilized nanocomposite with 6 wt.% of MMT-ODA is similar to neat polyethylene, whereas the composition having the same amount of MMT-ODA, without compatibilizer, exhibits poorer drawability. Scanning electron microscopy and density measurements of drawn samples indicate the existence of pores in noncompatibilized composite while no pores and good adhesion to MMT-ODA are found in compatibilized nanocomposites.  相似文献   

11.
Blends of recycled poly(ethylene terephthalate) (R-PET) and linear low density polyethylene (LLDPE) were compatibilized with poly(styrene-ethylene/butyldiene-styrene) (SEBS) and maleic anhydride-grafted poly(styrene-ethylene/butyldiene-styrene) (SEBS-g-MA). Effects of compatilizer were evaluated systematically by study of mechanical, thermal and morphology properties together with crystallization behavior of PET. Tensile properties of the blends were improved effectively by the addition of 10 wt% SEBS-g-MA, elongation at break and charpy impact strength were increased with the increasing content of compatilizer. SEBS-g-MA is more effectual on mechanical properties of R-PET/LLDPE blends than SEBS. DSC analysis illustrates crystallinities of PET and LLDPE were increased by compatilizer at annealing condition. WAXD and FT-IR spectra show that annealing influences crystallization behavior of PET. Different compatilizer content results in different morphology structure, in particular, higher SEBS-g-MA content can induce the formation of a salami microstructure.  相似文献   

12.
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.  相似文献   

13.
Poly [styrene‐b‐(ethylene‐co‐butylene)‐b‐styrene] (SEBS)/sepiolite clay nanocomposites are prepared by solvent casting method. Two types of schemes have been adopted to establish the compatibility between nonpolar polymer (SEBS) and needle‐like inorganic filler (sepiolite), either by polar modification of the nonpolar polymer or organic modification of the inorganic filler. Structure–property correlation of nanocomposites derived from two different approaches is compared. Structural and morphological analysis of nanocomposites has been investigated by Fourier transform infrared spectroscopy, X‐ray diffraction, field emission scanning electron microscopy and transmission electron microscopy. Fourier transform infrared result shows better compatibility between SEBS and modified sepiolite clay compared to maleic anhydride grafted SEBS and pristine sepiolite in their nanocomposites. Tensile strength and % elongation are found to increase by 32 and 105%, respectively, with the addition of just 3 parts per hundred parts of resin (phr) modified sepiolite clay to pristine SEBS matrix. Moreover, thermal stability has also improved by 96°C with similar loading. This work provides a new insight into the structure and thermo‐mechanical properties of novel SEBS–sepiolite clay nanocomposites. Copyright © 2017 John Wiley & Sons, Ltd.  相似文献   

14.
Binary blends of polypropylene (PP)/recycled poly(ethylene terephthalate) (r-PET), r-PET/maleic anhydride grafted PP (PP-g-MA), r-PET/glycidyl methacrylate grafted PP (PP-g-GMA), and ternary blends of PP/r-PET (80/20 w/w) compatibilized with various amounts (2-10 wt%) of PP-g-MA or PP-g-GMA were prepared on a twin-screw extruder. The non-isothermal crystallization and melting behavior, and the crystallization morphology were investigated by DSC and POM. The chemical reactions of r-PET with PP-g-MA and PP-g-GMA were characterized by FT-IR. DSC results show that the crystallization peak temperatures of r-PET and PP increased when blending them together, due to the heterogeneous nucleation effect on each other. The of r-PET increased with increasing the content of PP-g-MA while slightly influenced by the content of PP-g-GMA in the binary blends of r-PET with grafted PP, implying different reactivity of r-PET with PP-g-MA and PP-g-GMA. The of PP in the ternary blends retained or slightly decreased, dependent on the compatibilizers and their contents. The melting peak temperature of r-PET in PP/r-PET blends compatibilized by PP-g-MA was lower than that of compatibilized by PP-g-GMA, indicating that PP-g-MA had stronger reactivity towards r-PET compared to PP-g-GMA. The crystallization and melting behavior of blends was influenced by the pre-melting temperature, especially the melting behavior of r-PET in the blends. The crystallization behavior of PP in the blends was also evaluated by Mo’s method. POM confirmed the heterogeneous nucleation effect of r-PET on PP.  相似文献   

15.
In this study, the use of low molecular weight oxidized polyethylenes (OxPE) with different molecular weight and acid number as a new type of compatibilizer in low density polyethylene (LLDPE)/org-clay nanocomposite preparation was examined. Nanocomposites having 5 phr (part per hundred) org-clay were prepared by melt processing. The effect of compatibilizer polarity and clay dispersion on the thermal, mechanical and barrier properties of the nanocomposites was investigated. It was observed that oxidized polyethylenes created a strong interfacial interaction between the clay layers and polymer phase based on the analysis of the linear viscoelastic behavior of the samples by small amplitude oscillatory rheometry. We showed that physical performance of the nanocomposites is not only affected by clay dispersion but also both melt viscosity and polarity of the oxidized polyethylene compatibilizers. It was found that oxygen permeability values of the nanocomposite samples prepared with the oxidized polyethylenes were lower than that of a sample prepared with conventional compatibilizer, maleic anhydride grafted polyethylene (PE-g-MA).  相似文献   

16.

The effects of various compatibilizers on thermal, mechanical and morphological properties of 50/50 polypropylene/polystyrene blends were investigated. Various compatibilizers, polystyrene-(ethylene/butylenes/ styrene) (SEBS), ethylene vinyl acetate (EVA), polystyrene-butylene rubber (SBR) and blend of compatibilizers SEBS/PP-g-MAH, EVA/PP-g-MAH, and SBR/PP-g-MAH were used. Differential scanning calorimetry, thermogravimetric analysis, wide-angle X-ray scattering, scanning electron microscopy, microhardness, and Izod impact strength were adopted. It was found that the influence of various compatibilizers was appeared on all the properties studied. The properties of the blends compatibilized with SEBS, EVA, and SBR are very distinct from those of blends compatibilized with blend of compatibilizers. Results show that compatibilized blends with the blend of compatibilizers EVA/PP-g-MAH, SBR/PP-g-MAH, and SEBS/PP-g-MAH or SBR were relatively more stable than the uncompatibilized blend and blend compatibilized with SEBS or EVA. The compatibilizer does not only reduce the interfacial tension or increase the phase interfacial adhesion between the immiscible polymers, but greatly affects the degree of crystallinity of blends.

  相似文献   

17.
Annealing of maleated polypropylene/organoclay nanocomposites is studied at a range of temperatures from 180 °C to 300 °C under a stream of nitrogen and nitrogen/air mixtures. The study comprises determinations of the migration of clay to the surface by the use of attenuated total reflectance Fourier transform infra red (ATR-FTIR) spectra. The extent of migration is shown to increase with the increase in the percent of maleic anhydride (MA) grafted onto the PP and with the percentage of air added to the nitrogen gas used for purging of the samples during annealing. The extent of migration increases with temperature up to 225 °C. At temperatures of 250-300 °C, the extent of migration decreases. Simultaneously, a change in the structure of the nanocomposites is observed by small-angle X-ray diffraction (XRD), showing a conversion of the nanostructure to the non-colloidal microcomposite. The study conforms to previous findings and indicates that the migrating moiety is composed of exfoliated clay particles. The effect of the decomposition of the grafted MA groups and the evolution of CO2 on the rate of oxidation and migration are observed and discussed. The effect of the evolved CO2 on the stability of the clay particles is pointed out. The role of migration in the elucidation of the structure of nanocomposites is discussed along with other mechanistic considerations.  相似文献   

18.
Carboxylate clays: A model study for polypropylene/clay nanocomposites   总被引:1,自引:0,他引:1  
Sodium-montmorillonite was intercalated by carboxylate salts to prepare carboxylate clays. The intercalation of sodium acetate doubles the clay basal spacing and no degradation of the carboxylate clay is noticed in the extrusion temperature range. These carboxylate clays were used to synthesize polypropylene-graft-maleic anhydride (PP-g-MA)/clay nanocomposites. Nanocomposites were also produced by a one-pot process using in situ prepared carboxylate clay. The carboxylate salts within the clay layers partially neutralize the maleic anhydride groups of the PP-g-MA matrix, in situ during the melt compounding. The ionic groups of the partially neutralized polymer offer favourable interactions with the clay, hence reinforcing the interfacial bond between the polymer and the clay and improving the composite properties. The use of carboxylate clay clearly improves the clay dispersion into the PP-g-MA matrix and improves the nanocomposite’s thermal and rheological properties.  相似文献   

19.
A synthetic saponite-like clay, Sumecton SA (SSA), was self-assembled with 12-phosphotungstic acid (PTA) heteropolyacid for the preparation of new hybrid nanocomposites for proton exchange membranes. Thermogravimetric analysis (TGA) and Fourier transformed diffuse reflectance spectroscopy (DRIFT) measurements indicate the formation of robust PTA-SSA complexes. The Keggin structure of PTA is preserved within the complexes and is thermally stable up to 450 °C. The amount of PTA incorporated into the clay depends on the PTA-SSA weight ratio used for the complex preparation. PTA incorporation achieved is approximately 2-3 times the PTA content of most reported literature. However, higher PTA incorporation is accompanied by a significant loss of structural clay integrity. Low PTA-SSA weight ratios tend to preserve clay structure, but do not preclude its general amorphization generated by the PTA acidic treatment. PTA-SSA complexes present a low degree of order. Inorganic complexes were blended by melt extrusion with chemically-modified styrene/ethylene-co-butylene/styrene block copolymer (SEBS). Poly(oxyethylene/oxypropylene)-grafted-SEBS is more efficient than maleic anhydride-grafted-SEBS at dispersing PTA-SSA complexes. For both nanocomposite systems, nanoparticles’ size varies between 30 and 300 nm.  相似文献   

20.
Polypropylene (PP) blends with acrylonitrile-butadiene-styrene (ABS) were prepared using the styrene-ethylene-butylene-styrene copolymer (SEBS) as a compatibilizing agent. The blends were prepared in a co-rotational twin-screw extruder and injection molded. Torque rheometry, Izod impact strength, tensile strength, heat deflection temperature (HDT), differential scanning calorimetry, thermogravimetry, and scanning electron microscopy properties were investigated. The results showed that there was an increase in the torque of PA6/ABS blends with SEBS addition. The PP/ABS/SEBS (60/25/15%) blend showed significant improvement in impact strength, elongation at break, thermal stability, and HDT compared with neat PP. The elastic modulus and tensile strength have not been significantly reduced. The degree of crystallinity and the crystalline melting temperature increased, indicating a nucleating effect of ABS. The PP/ABS blends compatibilized with 12.5% and 15% SEBS presented morphology with well-distributed fine ABS particles with good interfacial adhesion. As a result, thermal stability has been improved over pure PP and the mechanical properties have been increased, especially impact strength. In general, the addition of the SEBS copolymer as the PP/ABS blend compatibilizer has the advantage of refining the blend's morphology, increasing its toughness and thermal stability, without jeopardizing other PP properties.  相似文献   

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