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1.
Multiwall carbon nanotube reinforced poly (phenylene sulfide) (PPS) nanocomposites were successfully fabricated through melt compounding. Structural, electrical, thermal, rheological, and mechanical properties of the nanocomposites were systematically studied as a function of carbon nanotube (CNT) fraction. Electrical conductivity of the polymer was dramatically enhanced at low loading level of the nanotubes; the electrical percolation threshold lay between 1 and 2 wt % of the CNTs. Rheological properties of the PPS nanocomposites also showed a sudden change with the CNT fraction; the percolation threshold was in the range of 0–0.5 wt % of CNTs. The difference in electrical and rheological percolation threshold was mainly due to the different requirements needed in the carbon nanotube network in different stages. The crystallization and melting behavior of CNT‐filled PPS nanocomposites were studied with differential scanning calorimetry; no new crystalline form of PPS was observed in the nanocomposites, but the crystallization rate was reduced. The thermal and mechanical properties of the nanocomposites were also investigated, and both of them showed significant increase with CNT fraction. For 5 wt % of CNT‐filled PPS composite, the onset of degradation temperature increased by about 13.5°C, the modulus increased by about 33%, and tensile strength increased by about 172%. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献
2.
Poly(ethylene terephthalate)/multiwalled carbon nanotubes (PET/MWCNTs) with different MWCNTs loadings have been prepared by in situ polymerization of ethylene glycol (EG) containing dispersed MWCNTs and terephthalic acid (TPA). From scanning electronic microscopy images of nanocomposites, it can be clearly seen that the PET/MWCNTs composites with low‐MWCNTs contents (0.2 and 0.4 wt %) get better MWCNTs dispersion than analogous with high‐tube loadings (0.6 and 0.8 wt %). The nonisothermal crystallization kinetics was analyzed by differential scanning calorimetry using Mo kinetics equation, and the results showed that the incorporation of MWCNTs accelerates the crystallization process obviously. Mechanical testing shows that, in comparison with neat PET, the Young's modulus and the yield strength of the PET nanocomposites with incorporating 0.4 wt % MWCNTs are effectively improved by about 25% and 15%, respectively. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 相似文献
3.
To investigate the nucleation effect of hydroxyl‐purified multiwalled carbon nanotubes (MWNTs‐OH) in poly(p‐phenylenesulfide) (PPS), a series of composites were prepared by blending PPS with MWNTs‐OH at 1, 2, and 3 wt %, respectively. Under SEM observation MWNTs‐OH were found homogeneously dispersed in the PPS matrix. DSC thermograms revealed that the enthalpy (ΔHc) of the composites increased with increasing MWNT‐OH content, whereas the crystallization temperature (Tc) decreased progressively. The decrease in Tc was in accordance with the smaller crystallite size determined with WXRD characterization, and the increase in ΔHc was evidenced by FTIR and XPS analyses. The higher ΔHc shows that MWNTs‐OH serves as a nucleating agent, providing sufficiently multiplied sites for crystal growth. The lowering of Tc was attributed not only to MWNTs‐OH network hindrance to PPS chain fusing rearrangement, but also to a poorer affinity between MWNTs‐OH and PPS; both effects coordinately govern Tc of PPS/MWNTs‐OH composites. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 相似文献
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The nonisothermal crystallization kinetics of linear Poly(phenylene sulfide) (PPS) was studied with differential scanning calorimetry. Ozawa theory, Jeziorny model, and Mo equation were applied to describe the crystallization kinetics and to determine the crystallization parameters and mechanism of the linear PPS resin. The crystallization activation energies were also calculated using Kissinger formula and Flynn‐Wall‐Ozawa equation, respectively. According to the Ozawa model, it is found that instantaneous nucleation takes place during crystallization of PPS; the Ozawa exponent m is 3 in initial stage of crystallization; as the crystallization temperature decreases, the value of m reduces, and the growth rate of crystal almost keeps a constant. The Avrami exponent n obtained from Jeziorny model fluctuate around 1.84. Based on the Jeziorny model, the crystallization rate increases with increasing the cooling rate, but it does not change any longer when the cooling rate rise to a certain value. Mo equation also exhibits great advantages in treating the nonisothermal crystallization kinetics of PPS. The activation energy E of nonisothermal crystallization process of PPS is calculated to be −162.73 kJ/mol by the Kissinger formula, and the mean value of E determined by Flynn‐Wall‐Ozawa equation is −152.40 kJ/mol. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 相似文献
6.
Ri‐Chao Zhang Yi Xu Zhongyuan Lu Min Min Yong Gao Yigang Huang Ai Lu 《应用聚合物科学杂志》2008,108(3):1829-1836
The morphology of nonisothermally crystallized poly(phenylene sulfide) (PPS) and its blend with poly (ether ether ketone) (PEEK) have been observed by polarized optical microscope (POM) equipped with a hot stage. The nonisothermal crystallization behavior of PPS and PEEK/PPS blend has also been investigated by differential scanning calorimetry (DSC). The maximum crystallization temperature for PEEK/PPS blend is about 15°C higher than that of neat PPS, and the crystallization rate, characterized by half crystallization time, of the PEEK/PPS blend is also higher than that of the neat PPS. These results indicate that the PEEK acts as an effective nucleation agent and greatly accelerates the crystallization rate of PPS. The Ozawa model was used to analyze the nonisothermal crystallization kinetics of PPS and its blends. The Avrami exponent values of neat PPS are higher than that of its blend, which shows that the presence of PEEK changed the nucleation type of PPS from homogeneous nucleation to heterogeneous nucleation. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
7.
We present the first study and results on the preparation and characterization of montmorillonite clay filler based polymer blend nanocomposites of the miscible poly(phenylene oxide)/polystyrene blend. Intercalated nanocomposites, prepared by a melt‐processing method with 2–6 wt % commercially available organically modified sodium montmorillonite, have been characterized with wide‐angle X‐ray diffraction, transmission electron microscopy analysis, thermal analysis (thermogravimetric analysis and differential scanning calorimetry), and mechanical tensile tests. We show that nanocomposites can be successfully prepared in a batch mixer at temperatures much below the conditions conventionally used for this blend without organic degradation. Thermal stability is enhanced by nanoscale hybrid formation. The level of intercalation (change in the d‐spacing) does not change with the clay loading. Better dispersion of clay in the blend matrix has been observed at a low level of clay content. The nanocomposites show improved tensile modulus (by 31%) in comparison to the blend, whereas the tensile strength (stress at break) and elongation decrease in the presence of the filler with an increase in the clay loading. The Halpin–Tsai model is able to predict the modulus of the nanocomposites in very good agreement with the experimental data. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
8.
Poly(p‐phenylene benzobisoxazole)/multiwalled carbon nanotubes (PBO‐MWCNT) composites with different MWCNT compositions were prepared through in situ polymerization of PBO in the presence of carboxylated MWCNTs. The nanocomposite's structure, thermal and photophysical properties were investigated and compared with their blend counterparts (PBO/MWCNT) using Fourier transform infrared spectra, Raman spectra, Wide‐angle X‐ray diffraction, thermogravimetric analysis, UV‐vis absorption, and photoluminescence. The results showed that MWCNTs had a strong interaction with PBO through covalent bonding. The incorporation of MWCNTs increased the distance between two neighboring PBO chains and also improved the thermal resistance of PBO. The investigation of UV‐vis absorption and fluorescence emission spectra exhibited that in situ PBO‐MWCNT composites had a stronger absorbance and obvious trend of red‐shift compared with blend PBO/MWCNT composites for all compositions. This behavior can be attributed to the efficient energy transfer through forming conjugated bonding interactions in the PBO‐MWCNT composites. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 相似文献
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Poly(vinylidene fluoride) (PVDF) nanocomposites with different loadings of multiwalled carbon nanotubes (MWNT) were prepared by melt‐compounding technique. A homogeneous dispersion of MWNT throughout PVDF matrix was observed on the cryo‐fractured surfaces by scanning electron microscopy. Thermogravimetric analysis results indicated that the thermal stability of neat PVDF was improved with the incorporation of MWNT. Dynamic mechanical analysis showed a significant improvement in the storage modulus over a temperature range from ?125 to 75°C with the addition of MWNT. The melt‐rheological studies illustrated that incorporating MWNT into PVDF matrix resulted in higher complex viscosities (|η*|), storage modulus (G′), loss modulus (G″), and lower loss factor (tan δ) than those of neat PVDF. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献
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The mechanical properties of poly(1‐butene) reinforced by pristine multiwalled carbon nanotubes (MWNTs) and polypropylene‐grafted MWNTs (PP‐g‐MWNTs) were evaluated. The incorporation of pristine MWNTs to PB led to an improvement in stiffness, but not in strength, ductility, and toughness. In comparison, PP‐g‐MWNTs were able to improve the stiffness, strength, and toughness of PB significantly, without compromising the ductility. The mechanical properties of PB improved with increasing amount of PP‐g‐MWNTs up to an effective MWNT content of 1.5 wt%. Further increase in the effective MWNT content led to a downturn in mechanical properties due to the existence of MWNTs bundles as observed by microscopy. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献
11.
The morphology and nonisothermal crystallization behavior of blends made of poly(phenylene sulfide) (PPS), with a amorphous polycarbonate (PC) were studied. The blend is found to be partially miscible by the dynamic mechanical thermal analysis (DMTA) and melt rheological measurements. The nonisothermal crystallization behavior of blend was studied by differential scanning calorimetry (DSC). The results show clearly that the crystallization temperatures of PPS component in the blend decrease with increasing of PC contents. The crystallization kinetics was then analyzed by Avrami, Jeziorny, and Ozawa methods. It can be concluded that the addition of PC decreases the PPS overall crystallization rate because of the higher viscosity of PC and/or partial miscibility of blend, despite of small heterogeneous nucleation effect by the PC phase and/or phase interface. The results of the activation energy obtained by Kissinger method further confirm that the amorphous PC in the partial miscible PPS/PC blend may act as a crystallization inhibitor of PPS. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007 相似文献
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The crystallization and multiple melting behavior of poly(phenylene sulfide) (PPS) and its blends with amorphous thermoplastic bisphenol A polysulfone (PSF) and phenolphthalein poly(ether ketone) (PEK-C), crystalline thermoplastic poly(ether ether ketone) (PEEK), and thermosetting bismaleimide (BMI) resin were investigated by a differential scanning calorimeter (DSC). The addition of PSF and PEK-C was found to have no influence on the crystallization temperature (Tc) and heat of crystallization (ΔHc) of PPS. A significant increase in the value of Tc and the intensity of the Tc peak of PPS was observed and the crystallization of PPS can be accelerated in the presence of the PEEK component. An increase in the Tc of PPS can also be accelerated in the BMI/PPS blend, but was no more significant than that in the PEEK/PPS blend. The Tc of PPS in the PEEK/PPS blends is dependent on the maximum temperature of the heating scans and can be divided into three temperature regions. The addition of a second component has no influence on the formation of a multiple melting peak. The double melting peaks can also be observed when PPS and its blends are crystallized dynamically from the molten state. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 637–644, 1998 相似文献
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Poly(phenylene sulfide ketone) (PPSK) was synthesized by the reaction of sodium sulfide with 4,4′‐dichlorobenzophenone in N‐methyl‐2‐pyrrolidinone through the Phillips process. The effect of water hydration of sodium sulfide in solution, polymerization temperature, polymerization time, and stoichiometric ratio of monomers on the polymerization behavior of PPSK were investigated with respect to inherent viscosity and yield. Thermal degradation parameters of PPSK synthesized were investigated by dynamic thermogravimetry. To determine thermal degradation energy, Kissinger, Ozawa, and Friedman methods were used and activation energies were 202.3, 233.6, and 232.2 kJ/mol, respectively. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 1329–1337, 2000 相似文献
14.
摘要：液晶聚合物(LCP)的低熔接线强度是限制LCP应用的重要因素。为了提升LCP材料的力学性能,利用熔融加工方式制备不同LCP含量的聚苯硫醚(PPS)/LCP复合材料。DSC测试结果显示,当复合材料中LCP质量分数小于30%时,LCP的异相成核作用可提升PPS的结晶温度;随着LCP含量的进一步增加,PPS的结晶被抑制,复合材料的结晶温度逐渐降低。对于玻璃纤维(GF)增强PPS/LCP复合材料,随着LCP含量的增加,复合材料的拉伸强度和弯曲强度逐渐降低,弯曲弹性模量逐渐升高;而复合材料的熔接线拉伸强度随着LCP含量增加呈现出先降低后增加的趋势。微观结构观察显示,GF增强PPS/LCP复合材料的性能与PPS/LCP两相界面结合以及树脂/GF之间的界面结合作用较差有关。进一步利用乙烯-丙烯酸甲酯-甲基丙烯酸缩水甘油酯无规三元共聚物和环氧树脂提升GF增强PPS/LCP复合材料的界面相互作用,结果显示,环氧树脂可以显著提升复合材料的力学性能,同时复合材料的熔接线拉伸强度由31 MPa提升至70 MPa。 相似文献
15.
Jinhuan Li Xiangqun Chen Xia Li Hailin Cao Hongyan Yu Yudong Huang 《Polymer International》2006,55(4):456-465
Carbon nanotube/poly(p‐phenylene benzobisoxazole) (CNT/PBO) composite fibres were prepared by in situ polymerization and dry‐jet wet spinning. The structure and properties of the CNT/PBO fibres were investigated. FTIR and viscosity measurements showed that the functional groups on the CNT surface took part in the polymerization and affected the chemical structure and molecular weight of the composite. CNT/PBO composites with high molecular weight could be obtained by controlling the amount and addition time of CNTs. Compared with PBO fibres containing no CNTs prepared under the same conditions, the thermal resistance of the CNT (2 wt%)/PBO fibres was higher and the tensile strength was also improved by 20–50%. WAXD and SEM measurements indicated that the orientation degree of the CNT (2 wt%)/PBO fibres was smaller than that of PBO fibres. The fracture surfaces of these two fibres were also different. CNT dispersion in the CNT (2 wt%)/PBO fibres was examined by TEM. A model of the interactions between CNTs and PBO is proposed, based on these results. Copyright © 2006 Society of Chemical Industry 相似文献
16.
PLA/PBAT blends and PLA/PBAT/MWNT nanocomposite systems were prepared via a melt mixing process to examine their thermal and rheological properties. To compare the polymer blend/MWNT nanocomposite with a pure polymer/MWNT nanocomposite, PLA/MWNT, PBAT/MWNT, and PLA/PBAT/MWNT nanocomposite systems were prepared. TEM and SEM were used to observe that one phase has better affinity with the MWNT, while the MWNT was found to increase both the thermal properties of the PLA/PBAT blends and rheological properties of the PLA/PBAT/MWNT nanocomposite with distinct shear‐thinning behavior due to the addition of the MWNT. An increase in the storage (G′) and loss (G″) moduli for the PLA/PBT/MWNT nanocomposite was also observed.
17.
Guoyong Xu Longchao Du Hu Wang Ru Xia Xiangchun Meng Qingren Zhu 《Polymer International》2008,57(9):1052-1066
BACKGROUND: The technological development of poly(ε‐caprolactone) (PCL) is limited by its short useful lifespan, low modulus and high crystallinity. There are a few papers dealing with the crystallization behavior of carbon nanotube‐reinforced PCL composites. However, little work has been done on the crystallization kinetics of melt‐compounded PCL/multiwalled carbon nanotube (MWNT) nanocomposites. In this study, PCL/MWNT nanocomposites were successfully prepared by a simple melt‐compounding method, and their morphology and mechanical properties as well as their crystallization kinetics were studied. RESULTS: The MWNTs were observed to be homogeneously dispersed throughout the PCL matrix. The incorporation of a very small quantity of MWNTs significantly improved the storage modulus and loss modulus of the PCL/MWNT nanocomposites. The nonisothermal crystallization behavior of the PCL/MWNT nanocomposites exhibits strong dependencies of the degree of crystallinity (Xc), peak crystallization temperature (Tp), half‐time of crystallization (t1/2) and Avrami exponent (n) on the MWNT content and cooling rate. The MWNTs in the PCL/MWNT nanocomposites exhibit a higher nucleation activity. The crystallization activation energy (Ea) calculated with the Kissinger model is higher when a small amount of MWNTs is added, then gradually decreases; all the Ea values are higher than that of pure PCL. CONCLUSION: This paper reports for the first time the preparation of high‐performance biopolymer PCL/MWNT nanocomposites prepared by a simple melt‐compounding method. The results show that the PCL/MWNT nanocomposites can broaden the applications of PCL. Copyright © 2008 Society of Chemical Industry 相似文献
18.
Crystallization and melting behavior of poly(p‐phenylene sulfide) in blends with poly(ether sulfone)
Mitsuhiro Shibata Ryutoku Yosomiya Zhenhua Jiang Zhenzhong Yang Guibin Wang Rongtang Ma Zhongwen Wu 《应用聚合物科学杂志》1999,74(7):1686-1692
Crystallization and melting behaviors of poly(p‐phenylene sulfide) (PPS) in blends with poly(ether sulfone) (PES) prepared by melt‐mixing were investigated by differential scanning calorimetry (DSC). The blends showed two glass transition temperatures corresponding to PPS‐ and PES‐rich phases, which increased with increasing PES content, indicating that PPS and PES have some compatibility. The cold crystallization temperature of the blended PPS was a little higher than that of pure PPS. Also, the heats of crystallization and melting of the blended PPS decreased with increasing PES content, indicating that the degree of crystallinity decreased with an increase of PES content. The isothermal crystallization studies revealed that the crystallization of PPS is accelerated by blending PPS with 10 wt % PES and further addition results in the retardation. The Avrami exponent n was about 4 independent on blend composition. The activation energy of crystallization increased by blending with PES. The equilibrium melting point decreased linearly with increasing PES content. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 1686–1692, 1999 相似文献
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原位复合法制备多壁碳纳米管／聚对苯二甲酸乙二酯复合物 总被引：1，自引：1，他引：0
采用原位复合方法,合成了不同多壁碳纳米管（MWNTs）含量的PET纳米复合物。实验中采用超声波辅助（方法A）和球磨辅助（方法B）两种分散方法？用扫描电子显微镜（SEM）、差示扫描量热分析fDSC）、Instron拉伸实验等手段对MWNTs及其在PET基质中的形态、复合物的熔融和结晶行为以及物理机械性能进行了袁征。结果表明：MWNTs能够均匀分散于PET中,且长径比较小的MWNTs的分散程度更好一些。聚合物熔体结晶过程中,MWNTs具有明显的成核作用,最大可使熔融结晶温度提高24．1℃。与纯PET材料相比,含0．4％MWNTs的PET复合材料（A—PET-4）的拉伸强度和杨氏模量分别提高约17％和25％,断裂仲长率则大幅度降低。 相似文献
20.
聚苯硫醚/玻璃微珠复合材料体系的相容性及非等温结晶动力学研究 总被引：3，自引：0，他引：3
采用熔融共混挤出法制备了聚苯硫醚(PPS)/玻璃微珠(GB)复合材料,考察了PPS/GB复合材料的相容性、结晶形态,并采用Ozawa方程和R-t关系法研究了复合材料的非等温结晶动力学。结果表明,PPS/GB复合材料在熔融状态下两相之间有良好的相容性,而在固态条件下随着GB含量增加存在分散不均匀现象。复合体系中PPS主要生成球晶,GB在PPS基体中起异相成核作用,加速其结晶。Ozawa方程和R-t关系法能较好地描述复合材料的非等温结晶动力学。 相似文献