【作者】 陈建兵；

【导师】 郭强；

【作者基本信息】 上海大学 ， 材料学， 2013， 博士

【摘要】 通过合金化改性获得优异综合性能的塑料合金在近些年倍受关注。由于高性能工程塑料聚醚醚酮（PEEK）在力学性能、热稳定性、电绝缘性及化学稳定性等方面具有突出的优势，但其价格昂贵，且玻璃化温度明显低于耐高温的无定形塑料如聚醚酰亚胺（PEI）、聚醚砜（PES），因此对PEEK合金化改性成为研究热点，如分别采用PEI或PES与PEEK共混，获得PEI/PEEK或PES/PEEK等二元合金，提高其高温刚性，降低成本。然而，至今未见涉足PEEK/PEI/PES三元合金。本文选择PEEK/PEI/PES的质量百分比分别为：70/30/0、70/0/30、70/25/5、65/30/5、60/30/10、60/35/5、60/10/30，采取370℃左右高温双螺杆挤出成型工艺制备塑料合金的片材和粒料试样，粒料再经热压模塑成型制备板材试样。采用SEM、XPS、FTIR-ATR、DSC、电子拉力试验机、滑动摩擦磨损试验机等检测手段对三元合金粒料、片材和板材试样进行微观结构分析、热性能、力学性能、摩擦磨损性能等进行测试分析，探讨三元合金组成对材料结构及各项性能的影响规律和作用机理。微观结构分析表明，在三元合金中PEEK、PEI、PES达到较均匀分散，呈现微观分相，宏观均匀分散的相形态结构。而PEEK与PES合金化时，分相较为明显。质量百分比60/30/10的三元合金表面XPS分析表明在极小区域内同时存在三种合金组分，显示三组分分散均匀。FTIR与FTIR-ATR显示三元合金中三组分PEEK、PEI、PES的各基团间存在相互作用，尤其亚胺环羰基红外吸收峰的变化证明因PES的加入，使三元合金中PEEK与PEI相互作用和无相互作用的区域同时存在。DSC分析进一步证明三元合金具有单一玻璃化转变温度，PEEK、PEI、PES三组分均匀分散且相容，Tg高于纯PEEK约20℃左右。PEI和PES两种非晶态组份的加入，使得三元合金在降温过程的结晶温度低于纯PEEK约6-8℃，结晶度增大，质量百分比为60/30/10的三元合金中PEEK结晶度达到最大值37.76%，比纯PEEK的结晶度提高约4.1%。模压成型的热处理过程对三元合金材料的热稳定性影响较小。PEI、PES的加入对其拉伸强度、断裂伸长率有一定的影响，质量百分比为60/30/10的三元合金片材试样拉伸强度达到最高值90MPa，高于纯PEEK，断裂伸长率低于纯PEEK。合金片材试样在158℃和178℃下的168h热老化对其拉伸强度影响较小，而对断裂伸长率影响明显。三元合金板材试样的拉伸强度均大于纯PES，小于纯PEI，多数高于纯PEEK，其断裂伸长率均大于纯PEEK，质量百分比为60/30/10的拉伸强度达到最高值108.1MPa。合金板材试样的弯曲强度和弯曲模量均随PEEK含量降低而下降，但均大于纯PES。另外，三元合金板材试样的硬度高于纯PES和纯PEI。因此，三元合金中PEEK组分对材料刚性贡献较大，而PEI和PES对材料抗破化能力的贡献突出。二元、三元合金的磨合期约为40-50min，短于纯PEEK的90min。合金稳态期的摩擦系数大于纯PEEK。三元合金板材的磨损率均低于纯PES和PEI，仅为其1/4-1/6，但高于纯PEEK的磨损率，磨损机理主要为粘着磨损。当PES含量不变时，随PEI的增大三元合金板材的磨损率增大。PES的加入使三元合金板材在对磨钢环表面形成的转移膜易于脱落，导致磨损率增大，说明PES和PEI两种非晶态组分不利于三元合金的耐磨性。三元合金板材试样耐浓硫酸特性较之纯PEEK有一定程度的改善。质量百分比70/25/5的三元合金对丙酮的耐腐蚀性能较突出，对氯仿、N,N’-二甲基甲酰胺的耐腐蚀性能表现良好，未发生腐蚀。试剂的极性对合金材料腐蚀影响不明显。浓H2SO4腐蚀过程对材料的热稳定有影响，而丙酮、氯仿的腐蚀过程影响不大，其热分解温度基本不变。在三元合金中由于PES的加入，使得合金片材试样的氧指数下降，质量百分比70/30/0的OI值大于纯PEEK，达37.1%，而三元合金中PEI组分的增加提高材料的阻燃性能。质量百分比60/30/10三元合金板材试样的体积电阻率达到3.72×10¹⁷·cm，显著高于纯PEEK、纯PES，与纯PEI的体积电阻率相当。综合分析三元合金各项性能，质量百分比60/30/10配方材料综合性能较突出。更多还原

【Abstract】 It is well concerned by people that plastic alloys with excellent comprehensiveperformance could be obtained by alloying modification in the recent years. Poly(ether ether ketone)(PEEK) is one kind of high-performance engineering plastics,which has prominent advantages in mechanical strength, thermal stability, electricalinsulativity and chemical stability. But high price and significantly lower glasstransition temperature than some high heat-resistant amorphous plastics such as poly(ether imide)(PEI) and poly (ether sulphone)(PES), so PEEK were improved byalloying modification, which has become one of research hotspots. Blend of PEI, PESand PEEK, such as were used to improve their high-temperature rigidity and reducecosts. However, at present, the research on PEEK/PEI/PES ternary alloy hadn’t beenreported. In the paper, the particles and sheets of PEEK/PEI/PES alloys were preparedsuccessfully with high temperature twin-screw extrusion molding at370℃in massratios of70/30/0,70/0/30,70/25/5,65/30/5,60/30/10,60/35/5and60/10/30. Inaddition, the plates of PEEK/PEI/PES alloys were also prepared successfully withthermal compression molding. Some properties of particles, sheets and plates werecharacterized and analyzed by means of scanning electron microscope(SEM), x-rayphotoelectron spectroscopy(XPS), attenuated total reflection flourier transformedinfrared spectroscopy (FTIR-ATR), differential scanning calorimetry (DSC), universaltensile machine, friction and wear tester respectively, such as the microstructure,thermal properties, mechanical properties, friction and wear properties and so on.Microstructure analysis showed that PEI and PES can be well-balanced dispersedin PEEK matrix, so it was exhibited that there is morphology with macroscopicuniformly dispersion and microscopic phase separation. PEEK and PES has a lowercompatibility. The XPS analysis of mass ratio of60/30/10particle specimen showsthere is a presence of there components, and the three components is dispersed evenlyin the tiny area of the surface of the specimen tested. The FTIR and FTIR-ATRanalysis indicated that there is a certain interaction between the three components, and there are some regions in the alloys with interaction and without interaction betweenPEEK and PEI when PES was increased, which can be proved especially by thechange of infrared absorption peak carbonyl group of imide ring. DSC results indicatedthat the ternary alloys PEEK/PEI/PES have a good compatibility and only a singleglass transition temperature that is higher than that of pure PEEK about20℃, AddingPEI and PES can make crystallization temperature lower than that of pure PEEK about6-8℃, and the crystallinity can be increased, such as mass ratio of60/30/10particlespecimen is the largest, namely37.76%, which is higher than the crystallinity of purePEEK about4.1%. There is a little influence on the thermal stability of the ternaryalloy materials for the heat treatment process of thermal compression molding,There are some influences on the tensile strength and elongation at break, such asthe tensile strength of mass ratio of60/30/10sheet specimen has the maximum value,namely90MPa, which is higher than that of pure PEEK, and the elongation at break islower than that of pure PEEK. Its results showed that the tensile strength of the sheetspecimens is less affected after158℃and178℃heat aging for168h, and theelongation at break were influenced obviously. The tensile strength of alloy platespecimens are higher than that of pure PES, and lower than that of PEI, the majority ofalloy plate specimens are higher than pure PEEK, such as the tensile strength of massratio of60/30/10plate specimen has the maximum value, namely108.1MPa, but theelongation at break of ternary alloy plate specimens are higher that of pure PEEK.Flexural strength and flexural modulus of plates lowers along with PEEK contentreducing in the ternary alloys, which is higher than that of pure PES. In addition, thehardness of ternary alloys is higher than that of pure PEI and pure PES. So PEEK hasthe larger contribution to the rigid properties of the ternary alloys, and PEI and PEShave the larger contribution to the break-resistant capacity of the ternary alloys.The binary alloy and ternary alloys reach the steady wear stage about40-50min,which is shorter than that of pure PEEK. The friction coefficients of alloys in thesteady wear stage are higher than that of pure PEEK. The wear rate of alloy plates is lower than pure PES and PEI, and is1/4-1/6of that of pure PES and PEI, but which ishigher than pure PEEK. Alloys wear mechanism is mainly adhesive wear. Adding PEIcan increase the wear rate of alloy plates when PES contents cannot be changed. Inaddition, it can be observed that adding PES can cause to fall the transferred film off inthe friction process, and results in increasing wear and the specific wear rates, so PEIand PES that are the amorphous component is not conducive to the ternary alloy wearresistance.The concentrated H2SO4resistance of alloy plates had been improved by alloyingin a certain extent. The acetone resistance of mass ratio of70/25/5is preferably, inaddition, the chloroform and N, N dimethyl formamide resistance of mass ratio of70/25/5is also preferably, and the polarity of the reagent has a limit influence onreagent resistance of plastics alloy materials. TGA results of ally plate specimenscorroded by concentrated H2SO4showed that there are some influences on the thermalstability of alloy materials, but TGA results of ally plate specimens corroded byacetone or chloroform showed that there are a little influence on the thermal stability ofalloy materials, and its thermal decomposition temperature basically remain unchanged.Adding PES can decrease oxygen index of alloy sheet specimens, the oxygen index(OI) of mass ratio of70/30/0is37.1%, which is higher than that of pure PEEK. Withthe increasing of PEI, the flame retardancy of alloys would be improved. The volumeresistivity of mass ratio of60/30/10is3.72×1017·cm, which is higher than that ofpure PEEK and pure PEI obviously, and the volume resistivity of alloy plates reachesthe order of magnitude for volume resistivity of pure PEI.The comprehensive properties of mass ratio of60/30/10formula materials aremore outstanding when the properties of ternary alloys were analyzedcomprehensively.更多还原