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1.
分别采用乙烯–乙酸乙烯酯共聚物(EVAC)、氯化聚乙烯(CPE)和苯乙烯–丁二烯–苯乙烯共聚物(SBS)三种弹性体为增韧剂,研究增韧剂种类及用量对聚氯乙烯(PVC)/丙烯腈–丁二烯–苯乙烯塑料(ABS)复合材料冲击强度、拉伸强度和极限氧指数的影响,并对纳米CaCO_3填充改性PVC/ABS复合材料的力学性能、熔体流动速率和极限氧指数(LOI)进行探讨。结果表明,采用CPE增韧改性的PVC/ABS复合材料的力学性能和阻燃效果均优于EVAC和SBS改性体系;PVC/ABS/CPE/CaCO_3复合材料的缺口冲击强度在纳米CaCO_3用量为6份时达到极大值,随着纳米Ca CO3用量的增加,拉伸强度和弯曲强度逐渐下降,LOI有所降低,在纳米CaCO_3用量为4份时材料的加工流动性较好。  相似文献   

2.
CaCO3粒子对PVC/CPE/CaCO3复合材料力学性能的影响   总被引:5,自引:1,他引:4  
采用SEM及材料力学性能试验方法,研究了表面处理剂品种、CaCO3颗粒直径对PVC/CPE/CaCO3复合材料力学性能的影响。结果表明:采用平均粒径为1.36μm并经烷氧焦磷酰氧基钛酸异丙酯(NDZ)和端噁唑啉聚醚(ON337)复合偶联剂处理的CaCO3改性PVC/CPE(100/10)复合材料,可使复合材料的缺口冲击强度明显提高,并在CaCO3含量为10份时达到极大值;此条件下被改性材料的Charpy缺口冲击强度提高75%以上,达到46.3kJ/m^2,而其拉伸强度和弯曲强度变化不明显。当CaCO3颗粒尺寸较大时,即使采用NDZ ON337复合偶联助剂处理,此种CaCO3颗粒对PVC/CPE复合材料也不具备明显增韧作用。  相似文献   

3.
选择氯化聚氯乙烯(CPVC)、聚氯乙烯(PVC)为主体材料,研究了PVC/CPVC共混比、填料品种及用量等对PVC/CPVC合金体系力学性能的影响,同时利用扫描电镜对PVC/CPVC合金的微观结构进行了分析。结果表明,CPVC在加工过程中易发生脱HCl反应,PVC常用的铅盐稳定剂、有机锡类稳定剂均适于CPVC体系,且铅盐稳定剂的稳定效果要优于有机锡类稳定剂。当m(PVC)∶m(CPVC)从100∶0向70∶30变化时,随着CPVC含量的增多,PVC/CPVC二元合金体系的屈服强度、拉伸强度、弯曲强度、热变形温度(最大弯曲正应力分别为1.82 MPa和0.45 MPa)等均呈递增趋势,而冲击强度、断裂伸长率出现递减趋势。在填料用量为5份时,PVC/CPVC合金体系的力学性能以选用活性碳酸钙(CaCO3)为最佳。随着活性CaCO3用量的增加,PVC/CPVC合金的拉伸强度、弯曲强度、断裂伸长率呈先上升后下降的趋势。活性CaCO3用量的变化对冲击强度几乎无影响。当活性CaCO3用量超过10份时,PVC/CPVC合金的热变形温度上升。  相似文献   

4.
纳米CaCO3对PET/M-POE体系力学性能的影响   总被引:6,自引:0,他引:6  
陈俊  杨伟  黄锐 《中国塑料》2005,19(2):16-21
采用马来酸酐接枝乙烯-辛烯共聚弹性体(M-POE)和纳米CaCO3协同增韧聚对苯二甲酸乙二酯(PET)。结合复合材料的室温缺口冲击断面扫描电镜照片、淬断刻蚀照片和宏观力学性能,分析了复合体系发生脆-韧转变对应的微观形貌特征。结果表明,直接将M-POE、纳米CaCO3与PET熔融共混并不能起到协同增韧效果,随着纳米CaCO3含量的增加,三元复合体系的缺口冲击强度逐渐降低。纳米CaCO3经过不同表面处理后,在复合体系中的微观分布不同,从而导致体系力学性能变化。不同的加工工艺可以制得纳米CaCO3分布不同的复合材料。研究发现,纳米CaCO3分布于PET基体中会引起复合材料冲击强度的下降。而纳米CaCO3分布于弹性体中,即形成所谓的“沙袋结构”,不仅可以明显提高复合材料的冲击强度,还可降低橡胶用量。  相似文献   

5.
稀土稳定剂对PVC/CaCO3复合体系影响的研究   总被引:1,自引:0,他引:1  
测试并分析了稀土稳定剂对PVC/CaCO3复合材料的静态稳定时间、流变性能及力学性能的影响,并与复合铅稳定剂进行了对比实验。结果表明:稀土稳定剂在复合材料中表现出较好的热稳定性、加工性和增容偶联的功效;在相同的配比条件下,稀土稳定体系的拉伸强度和冲击韧性比复合铅稳定体系的高。复合材料试样的断面SEM照片显示CaCO3在稀土稳定体系中粒子分散均匀,进一步验证了稀土稳定剂有增容偶联的作用。  相似文献   

6.
PVC与纳米碳酸钙复合材料的结构与性能研究   总被引:2,自引:0,他引:2  
采用拉伸强度、断裂伸长率、冲击强度等力学参数对聚氯乙烯(PVC)/纳米CaCO3复合材料进行评价,并结合热重差示扫描量热仪、扫描电镜对复合材料的热稳定性和断面结构进行表征.结果表明:采用超声分散方法,选用NDZ-311/SG-Al 821复合改性剂改性的纳米CaCO3明显提高了PVC基复合材料的缺口冲击强度、断裂伸长率和热稳定性;当纳米CaCO3填充质量分数达15%时,PVC/纳米CaCO3复合材料的缺口冲击强度达22.34 kJ/m2,比未填充纳米CaCO3的提高了60.5%;当纳米CaCO3填充质量分数不高于20%时,用超声技术改性纳米CaCO3能很好地分散在PVC基体中.  相似文献   

7.
本文采用采用SEM及材料力学性能试验方法,研究了表面处理剂品种、CaCO3颗粒直径对PVC/CPE/Ca-CO3复合材料力学性能的影响。结果表明:采用平均粒径为1.36(m并经烷氧焦磷酰氧基钛酸异丙酯(NDZ)和端刲唑啉聚醚(ON337)复合偶联剂处理的CaCO3改性PVC/CPE(100/10)复合材料,可使复合材料的缺口冲击强度明显提高,并在CaCO3含量为10份时达到极大值;此条件下被改性材料的Charpy缺口冲击强度提高75%以上,达到46.3kJ/m^2,而其拉伸强度和弯曲强度变化不明显。当CaCO3颗粒尺寸较大时,此时即使采用NDZ ON337复合偶联助剂处理,此种CaCO3颗粒对PVC/CPE复合材料也不具备明显增韧作用。  相似文献   

8.
采用膨胀型阻燃剂[聚磷酸铵/季戊四醇/硼酸锌(APP/PER/ZB)体系]对交联乙烯–乙酸乙烯酯塑料(EVAC)进行阻燃改性,然后分别用CaCO3和可膨胀石墨(EG)进一步优化EVAC/APP/PER/ZB复合材料。采用极限氧指数(LOI)仪、锥形量热仪和扫描电子显微镜(SEM)研究了复合材料的阻燃性能及阻燃机理,并测试了复合材料的力学性能和介电性能。结果表明,随着APP/PER/ZB体系含量的增加,复合材料的LOI逐渐升高,热释放速率峰值、平均热释放速率、热释放总量逐渐降低;拉伸强度、断裂伸长率和介电常数逐渐下降,但介电损耗变化极小。CaCO3和EG优化的复合材料阻燃性能和拉伸性能均比未优化的有所提高,起到一定的协同阻燃效果,其中EG的优化效果最好;CaCO3对复合材料介电性能的影响与APP/PER/ZB体系大致相同,但高频下EG的影响较为显著,均明显降低了复合材料的介电常数和介电损耗峰值。  相似文献   

9.
PVC/CaCO3纳米复合材料结构与性能的研究   总被引:4,自引:0,他引:4  
研究了PVC/CaCO3纳米复合材料的力学性能和热性能,观察了复合材料冲击缺口的断面微观形态和纳米CaCO3粒子在PVC中的分散情况。结果表明:当纳米CaCO3粒子的质量分数为10%时,PVC/CaCO3纳米复合材料的冲击强度提高了约365%,拉伸强度略有提高;当纳米CaCO3质量分数超过10%以后,纳米粒子在基体中的分散情况变差;随着纳米CaO3用量的增加,PVC/CaCO3纳米复合材料的玻璃化转变温度先降后升。  相似文献   

10.
添加稀土稳定剂的PVC异型材的喷涂性能研究   总被引:1,自引:0,他引:1  
通过实验对比了添加稀土稳定剂REC-109与添加复合铅盐稳定剂德国熊牌50369的PVC异型材的喷涂性能。结果表明,随着稀土稳定剂所用的用量从2.6份增大到3.4份,氟碳涂料与添加稀土稳定剂的异型材试样表面的接触角从80.0°增大到85.0°,附着力低于复合铅盐稳定剂生产的PVC异型材,因此不适宜用于制造喷涂着色的异型材。并分析了原因,认为是由于稀土原子与PVC分子有很好的相容性,但与氟碳涂料分子相斥之故。  相似文献   

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Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.  相似文献   

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In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.  相似文献   

14.
Glycidyl carbamate chemistry combines the excellent properties of polyurethanes with the crosslinking chemistry of epoxy resins. Glycidyl carbamate functional oligomers were synthesized by the reaction of polyfunctional isocyanate oligomers and glycidol. The oligomers were formulated into coatings with several amine functional crosslinkers at varying stoichiometric ratios and cured at different temperatures. Properties such as solvent resistance, hardness, and impact resistance were dependent on the composition and cure conditions. Most coatings had an excellent combination of properties. Studies were carried out to determine the kinetics of the curing reaction of the glycidyl carbamate functional oligomers with multifunctional and model amines. Detailed kinetic analysis of the curing reactions was also undertaken. The results indicated that the glycidyl carbamate functional group is more reactive than a glycidyl ether group. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, on October 27–29, 2004, in Chicago, IL.  相似文献   

15.
A highly moisture-proof polysilsesquioxane coating was obtained from a new bis-silylated precursor, which was synthesized from 3-aminopropyltriethoxysilane (APTES) and m-xylylene diisocyanate (m-XDI) in tetrahydrofuran (THF) and verified by 1H MAS NMR. For direct comparison purposes, an SiO2 coating was also prepared by the Stöber method using tetraethoxysilane (TEOS) as the reactant. Interestingly, the coating obtained from the polysilsesquioxane sol exhibited a much higher moisture resistance capability than its counterpart, which was attributed to its more compact feature between nanoparticles as characterized by N2 absorption experiment and transmission electron microscopy (TEM). Furthermore, its high transparency of about 92% showed potential for application in the protection of optical crystals.  相似文献   

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Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.  相似文献   

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