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1.
酞侧基聚芳醚砜/对苯二甲酸乙二酯-对羟基苯甲酸嵌段共聚物共混物的研究李刚,殷敬华,李滨耀(中国科学院长春应用化学研究所,长春,130022)关键词酞侧基聚芳醚砜,热致性液晶高聚物,原位复合材料,对苯二甲酸乙二酯-对羟基苯甲酸嵌段共聚物将热塑性树脂与热...  相似文献   

2.
嵌段液晶高聚物对聚醚砜 聚对苯二甲酸乙二醇酯/聚对羟基苯甲酸共混物的增容作用张海良张雪飞王霞瑜(湘潭大学化学化工学院湘潭411105)关键词增容作用,嵌段共聚物,原位复合材料基于热致性液晶高分子(TLCP)的原位复合材料以其高性能及易加工等特点而得...  相似文献   

3.
报道了苯乙烯-丙烯等规嵌段共聚物增溶作用及iPS-b-iPP/iPS/iPP三组分共混体系微观形态和力学性能的研究结果。iPS-b-iPP的加入明显地改善了iPS/iPP二组分共混物的力学性能;共聚物含量超过15%时,三组分共混物的抗冲击强度超过HIPS的抗冲击强度,并具有较高的耐热性。SEM结果表明,iPS-b-iPP在iPS/iPP共混中起到了相分散和相间“偶联”作用,并降低了共混体系的微相尺  相似文献   

4.
采用二甲基硅氧烷-b-乙二醇嵌段共聚物(DMS-b-OE)对聚二甲基硅氧烷/聚氨酯(PDMS/PU)共混体系的增容,重点研究了增容共混体系的微观形态结构和软科学性能之间的关系。扫描电子显微镜、动态力学分析和力学性能测试结果表明:DMS-b-OE对PDMS/PU具有优良的增容作用,改善了PDMS/PU共混体系的相容性,提高了该共混物的力学性能。其抗张强度由3.4MPa提高到7.6MPa。  相似文献   

5.
PET/PA66/液晶共聚酯酰胺共混体系的流变性能   总被引:5,自引:0,他引:5  
采用SEM1、热偏光显微研究了聚对苯二甲乙二酯(PET)/聚酰胺66(PA66)/热致液晶共聚酯酰胺(LC30)三元共混物的形态结构;利用Instron3211型毛细管流变仪研究了共混物的流变性能,结果表明:PET/PA66/LC30共混物为一热力学不相容的多相聚合物体系,LC30的加入提高了PET/PA66的相容性,有效地改善了PET/PA66共混物的流变性能,PET/PA66/LC30三元共混  相似文献   

6.
报道了对嵌段共聚物结晶型共混体系结晶行为的研究.通过对聚甲基丙烯酸甲酯-聚四氢呋喃两嵌段共聚物/聚四氢呋喃共混体系的研究,我们发现1.微相分离结构的存在,可使相容的这类体系形成多种特殊的结晶形态;2.共混体系的相容性可以方便地由其结晶行为来判断;3.共混体系中共聚物的结晶能力显著提高.这些特点都明显不同于一般的聚合物共混体系.  相似文献   

7.
着重介绍嵌段共聚物/均聚物共混体系的微相分离,微胶束的形成,微区的形态结构以及形态的控制。  相似文献   

8.
利用DSC、DMA、TEM和XPS对[PSF-PDMS-PHS]n/PSF共混物的相容性及表面组成进行了研究.结果表明,PDMS在共混物表面的富集与PSF均聚物和[PSF-PDMS-PHS]n中硬段的相容性有关;PDMS在相容的共混物体系表面的富集与对应的多嵌段共聚物组成基本相近;不相容共混物体系表面PDMS的富集程度相对较高,当共混物本体中有机硅含量从1%增至5%,表面层PDMS的含量迅速增加,可达到嵌段共聚物中PDMS的含量.  相似文献   

9.
报道了苯乙烯-丙烯等规嵌段共聚物(iPS-b-iPP)增溶作用及iPS-b-iPP/iPS/iPP三组分共混体系微观形态和力学性能的研究结果。iPS-b-iPP的加入明显地改善了iPS/iPP二组分共混物的力学性能;共聚物含量超过15%时,三组分共混物的抗冲击强度超过NIPS的抗冲击强度,并具有较高的耐热性。SEM结果表明,iPS-b-iPP在iPS/iPP共混中起到了相分散和相间“偶联”作用,并降低了共混体系的微相尺寸和增加相间相互作用或粘附性。iPS-b-iPP/iPS/iPP共混合金具有高的软化温度和刚性。  相似文献   

10.
热致液晶共聚酯/Nylon-1010共混物的研究   总被引:4,自引:0,他引:4  
利用偏光显微镜(PLM),差示扫描量热计及广角X-射线衍射等手段研究了热致液晶共聚酯/Nylon-1010共混体系.发现当热致液晶共聚酯(HTH10)含量达到30%时共混物微结构与纯HTH10相似.尼龙-1010的结晶度先是随HTH10含量增加而增加,随后又随之下降,但其结晶温度却随HTH10加入而单调下降,共混物的熔融热焓△Hm在HTH10含量为30%时与计算值有较大的偏差,广角X-射线衍射结果表明,此时共混物结构发生了较为明显的变化,两组份之间在此时存在一定的相互作用.  相似文献   

11.
《Liquid crystals》2001,28(12):1855-1862
The surface tension of a low molar mass liquid crystal (LMMLC), 4-cyano-4'-n-heptyloxybiphenyl (70CB), was measured as a function of temperature using the pendant drop method, forming drops of different volumes ranging from 5 to 11 mm3. Contact angles formed by drops of 70CB in the nematic and isotropic phases on plates of polystyrene (PS) and of a liquid crystal polymer (LCP), VECTRA A910, were also measured. Only large drops could be used for surface tension analysis. It was shown that in the nematic phase the surface tension of 70CB decreases with increasing temperature, and that in the isotropic phase the surface tension increases with increasing temperature. Using the values of contact angle and of surface tension of 7OCB it was possible to evaluate the interfacial energy between 7OCB and PS and between 7OCB and VECTRA. The interfacial energy between 7OCB and PS, and between 7OCB and VECTRA, decreased with increasing temperature for ranges of temperatures corresponding to both phases of 70CB.  相似文献   

12.
The surface tension of a low molar mass liquid crystal (LMMLC), 4-cyano-4'-n-heptyloxybiphenyl (70CB), was measured as a function of temperature using the pendant drop method, forming drops of different volumes ranging from 5 to 11 mm3. Contact angles formed by drops of 70CB in the nematic and isotropic phases on plates of polystyrene (PS) and of a liquid crystal polymer (LCP), VECTRA A910, were also measured. Only large drops could be used for surface tension analysis. It was shown that in the nematic phase the surface tension of 70CB decreases with increasing temperature, and that in the isotropic phase the surface tension increases with increasing temperature. Using the values of contact angle and of surface tension of 7OCB it was possible to evaluate the interfacial energy between 7OCB and PS and between 7OCB and VECTRA. The interfacial energy between 7OCB and PS, and between 7OCB and VECTRA, decreased with increasing temperature for ranges of temperatures corresponding to both phases of 70CB.  相似文献   

13.
Abstract

Polyester elastomer (PEL) blends having a hard segment of polyester (PBT), soft segment of polyether (PTMG), and a liquid crystalline copolyester (LCP), poly(benzoate-naphthoate) were prepared with a twin-screw extruder. Test specimens for thermal properties were prepared by injection molding. Rheological properties and morphology were investigated by Instron capillary rheometer (ICR) and scanning electron microscopy (SEM). Thermal properties of the LCP/PEL blends were investigated by DSC, dilatometer, heat deflection temperature tester, and a Rheovibron viscometer. DSC study revealed a partial miscibility between LCP and PEL. It was found that the LCP acted as a nucleating agent for the crystallization of PEL in the LCP/PEL blends. The dimensional and thermal stability of the blends were increased by increasing the LCP cont-ent. The storage modulus (E' was improved by increasing the LCP content. The blend viscosity showed a minimum value at 5 wt% of LCP which increased by increasing the LCP content above 5 wt% of LCP The morphology of the LCP/PEL blends showed poor interfacial adhesion between the two phases, and the fibrillar structure of LCP phase in the matrix was affected by the LCP content, shear rate, and extrusion temperature. The morphology of the blends was found to be affected by their compositions and processing conditions.  相似文献   

14.
含热致液晶性共聚酯的聚砜共混物   总被引:1,自引:1,他引:1  
将一种含萘环的热致液晶性共聚酯与聚砜树脂熔融共混并挤塑成条。毛细管流变性测试表明,这一共聚酯降低了共混物的表观粘度,甚至低于其本身的粘度。共混物受剪切作用形成了各向异性的微纤增强结构,并具有皮芯结构,在液晶聚俣物含量低到2%与0.5%的样条中仍有共聚酯微纤形成。共聚酯微纤提高了聚砜的力学性能,含20%共聚酯共混物挤塑条的位伸模量为聚砜树脂的二倍半。  相似文献   

15.
Miscibility and crystallization behavior of solution-blended poly(ether ether ketone)/polyimide (PEEK/PI) blends were investigated by using DSC, optical microscopy and SAXS methods. Two kinds of PIs, YS-30 and PEI-E, which consist of the same diamine but different dianhydrides, were used in this work. The experimental results show that blends of PEEK/YS-30 are miscible over the entire composition range, as all the blends of different compositions exhibit a single glass transition temperature. The crystallization of PEEK was hindered by YS-30 in PEEK/YS-30 blends, of which the dominant morphology is interlamellar. On the other hand, blends of PEEK/PEI-E are immiscible, and the effect of PEI-E on the crystallization behavior of PEEK is weak. The crystallinity of PEEK in the isothermally crystallized PEEK/YS-30 blend specimens decreases with the increase in PI content. But the crystallinity of PEEK in the annealed samples almost keeps unchanged and reaches its maximum value, which is more than 50%. The spherulitic texture of the blends depends on both the blend composition and the molecular structure of the PIs used. The more PI added, the more imperfect the crystalline structure of PEEK. © 1998 John Wiley & Sons, Inc. J. Polym. Sci. B Polym. Phys. 36: 2267–2274, 1998  相似文献   

16.
含热致液晶性共聚酯的聚砜共混物   总被引:3,自引:0,他引:3  
将一种含萘环的热致液晶性共聚酯与聚砜材脂熔融共混并挤塑成条.毛细管流变性测试表明,这一共聚酯降低了共混物的表观粘度,甚至低于其本身的粘度.共混物受剪切作用形成了各向异性的微纤增强结构,并具有皮芯结构.在液晶聚合物含量低到2%与0.5%的样条中仍有共聚酯微纤形成.共聚酯微纤提高了聚砜的力学性能,含20%共聚酯共混物挤塑条的位伸模量为聚砜树脂的二倍半.  相似文献   

17.
Rhythmic growth of ring‐banded spherulites in blends of liquid crystalline methoxy‐poly(aryl ether ketone) (M‐PAEK) and poly(aryl ether ether ketone) (PEEK) has been investigated by means of differential scanning calorimetry (DSC), polarized light microscopy (PLM), and scanning electron microscopy (SEM) techniques. The measurements reveal that the formation of the rhythmically grown ring‐banded spherulites in the M‐PAEK/PEEK blends is strongly dependent on the blend composition. In the M‐PAEK‐rich blends, upon cooling, an unusual ring‐banded spherulite is formed, which is ascribed to structural discontinuity caused by a rhythmic radial growth. For the 50:50 M‐PAEK/PEEK blend, ring‐banded spherulites and individual PEEK spherulites coexist in the system. In the blends with PEEK as the predominant component, M‐PAEK is rejected into the boundary of PEEK spherulites. The cooling rate and crystallization temperature have great effect on the phase behavior, especially the ring‐banded spherulite formation in the blends. In addition, the effects of M‐PAEK phase transition rate and phase separation rate on banded spherulite formation is discussed. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 3011–3024, 2007  相似文献   

18.
The blends of phenolphthalein Polyethersulfone (PES - C ) and a thermotropic liquid crystalline polymer (LCP ) were prepared using melting mixing method.Rheological and mechanical properties of the blends were investigated. It was shown that addition of LCP in PES-C resulted in marked reduction of melt viscosity and improved processibility. The Chadly impact strength of the blend containing 2. 5% LCP increased about 2. 5 times comparing with pure PES-C. The tensile strength, Young's modulus, fie-cural strength and flexural modulus of the PES-C/LCP blends were also improved on some extent. The morphology of these blends were also observed by SEM,and the relationship between the me-chanical properties and the morphology of blends were discussed.  相似文献   

19.
The morphology of a special blend system composed of liquid crystalline aromatic random copolyester (LCP) and semiflexible polyester PET over the whole composition range has been studied by means of polarized microscope, density measurement, DSC, FTIR and SEM. Based on the microscopic observation, it is found that under suitable mechanical mixing condition, LCP may be rather homogeneously dispersed in the PET matrix, with the middle composition range of the contents of LCP at 30--70 wt % the anisotropic and isotropic phase segregation appears, while with LCP contents over 80 wt% the blends exhibit wholly anisotropie. The DSC thermographs of the melt-pressed and quenched films show single T_(?), T_(cc) and T_m. T_(?) increases with increasing content of LCP and ap, proaches to the T_(?) of pure LCP. The experimental results indicate that the two components of this blend system are miscible, there exist some specific interactions between them.  相似文献   

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