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PP/POE/纳米CaCO3复合材料流变性能的研究 总被引:2,自引:0,他引:2
研究了聚丙烯/聚烯烃热塑性弹性体/纳米CaCO3(PP/POE/纳米CaCO3)复合材料的流变性能,探讨了纳米CaCO3、POE添加量、剪切速率和温度对复合材料黏度的影响。实验数据显示,在较低剪切速率下,随纳米CaCO3添加量的增加,体系熔体黏度增加;在较高剪切速率下,随纳米CaCO3添加量的增加,体系黏度降低;增加POE添加量,复合体系的熔体黏度增大;纳米CaCO3的加入使复合体系的非牛顿指数减小,非牛顿性增强。PP/POE/纳米CaCO3(100/10/10质量份数,下同)体系具有高流动性,熔体流动速率达19.58g/10min。 相似文献
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通过熔融共混制得聚丙烯/聚乳酸/纳米碳酸钙(PP/PLA/CaCO3)复合材料,考察了PLA和纳米CaCO3对复合材料力学性能、热性能、流变性能与结晶形态的影响及其作用机理。结果表明,复合材料中形成连续空间网络结构的PLA有助于改善PP的性能,PLA含量为20 %(质量分数,下同)时复合材料综合力学性能最佳;与纯PP相比,加入PLA后的复合材料拉伸强度和冲击强度分别提高5.1 %和54.4 %,断裂伸长率降低62.5 %;纳米CaCO3通过“滚珠增韧”和“异相成核”作用明显改善复合材料力学性能,纳米CaCO3含量15 %时产生的晶粒细化作用效果最为显著,复合材料综合力学性能达到最佳,拉伸强度、断裂伸长率和冲击强度分别比未添加CaCO3时提升了15.2 %、2.7 %和5.6 %。 相似文献
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研究了不同的增韧剂(EPDM、HDPE、LDPE和SBS)对聚丙烯共混物力学性能的影响,EPDM含量为15%时,共混物的拉伸强度下降较小,冲击强度比纯聚丙烯提高450%。采用正交实验法,研究了纳米CaCO3和EPDM并用对PP共混物力学性能的影响,含量6%的纳米CaCO3具有增强和增韧作用;纳米CaCO3与EPDM并用能协同增强聚丙烯;PP/EPDM/纳米CaCO3的质量比为74/20/6时,聚丙烯共混体系的综合力学性能较好。 相似文献
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等通道转角挤出制备自增强等规聚丙烯的结构与性能研究,聚丙烯发泡体系粘度预测模型的确立,PP/POE/纳米CaCO3复合材料流变性能的研究,PP/SBS/纳米CaCO3复合材料结构与性能研究,聚丙烯基杂化材料的动态力学性能与流变行为. 相似文献
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利用反应性单体甲基丙烯酸(MA)接枝聚丙烯(PP)后,二步法制备了反应改性纳米CaCO3/PP复合材料。研究了复合材料的力学性能,并用扫描电子显微镜(SEM)观察了复合材料经液氮冷却脆断后断面的形态。结果表明,甲基丙烯酸接枝聚丙烯(MAPP)加入后与CaCO3反应使MAPP与纳米CaCO3微聚体之间产生离子键作用,使纳米/PP复合材料的力学性能得到大幅提升,对冲击性能的改善尤为明显。充分控制的MA反应量比单独依靠MAPP增容能够更为有效地提高纳米CaCO3的分散性和界面黏结性。 相似文献
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A new ampholytic homopolypeptide, , which has one tertiary amino and two carboxyl groups in the side chain has been derived from a hydrochloride salt of poly(L-lysine). The polymer in aqueous solution seems to be in the coil form with locally extended structure (LES) at neutral pH. In both the acidic and alkaline regions, the molar ellipticity of the polymer changes as a result of change in net charge on the side chain. The conformational changes may be from the coil with LES to other coiled forms. 5–7 M NaClO4 and 80% aqueous methanol induce the α-helix in the polymer at neutral pH. Divalent cations, Cu2+ and Ca2+, do not induce any remarkably ordered structures such as α-helix or β-structure in the polymer in aqueous solution at any pH. Ultraviolet absorption studies show an absorption peak of the polymer-Cu2+ complex near 240 nm. Dependence of the peak intensity on pH at various q values () indicates the two steps of the complex formation. At q less than 0.64, the formation is described only with the first step. An average coordination number for Cu2+ at the first step was calculated to be about 2 by the method of Mandel and Leyte. The association constant of Cu2+ with the residue at the step was determined from the absorption data to be far smaller than that for the Cu2+-EDTA complex. The second step of the formation occurs in the case of large q but the absorption data for the second step cannot be obtained exactly due to precipitation. 相似文献
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Silvia Schicker Daniel E. García Igor Gorlov Rolf Janssen Nils Claussen 《Journal of the American Ceramic Society》1999,82(10):2607-2612
Wet milling of Al2 O3 -aluminide alloy (3A) precursor powders in acetone has been investigated by milling Fe/Al/Al2 O3 and Fe2 O3 /Al/Al2 O3 powder mixtures. The influence of the milling process on the physical and chemical properties of the milled powders has been studied. Particle refinement and homogenization were found not to play a dominant role, whereas plastic deformation of the metal particles leads to the formation of dislocations and a highly disarranged polycrystalline structure. Although no chemical reactions among the powder components in Fe2 O3 /Al/Al2 O3 powder mixtures were observed, the formation of a nanocrystalline, ordered intermetallic FeAl phase in Fe/Al/Al2 O3 powder mixtures caused by mechanical alloying was detected. Chemical reactions of Fe and Al particle surfaces with the atmosphere and the milling media lead to the formation of highly porous hydroxides on the particle surfaces. Hence the specific surface area of the powders increases, while the powder density decreases during milling. The fraction of Fe oxidized during milling was determined to be 0.13. The fraction of Al oxidized during milling strongly depends on the metal content of the powder mixture. It ranges between 0.4 and 0.8. 相似文献
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Akira Akimoto 《Polymer》1974,15(4):216-218
The polymerization of vinyl chloride has been investigated using an catalyst system in the presence of various Lewis bases. Effective Lewis bases are γ-butyrolactone, diglyme and diethylenetriamine which are multidentate. The rate of polymerization is dependent not only on the basicity of the Lewis base used but also on a coordination number of one. The latter is the predominant factor. For the effect of polymeric amines, a tentative hypothesis is discussed. 相似文献
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Sintering kinetics of the system Si3 N4-Y2O3 -Al2 O3 were determined from measurements of the linear shrinkage of pressed disks sintered isothermally at 1500° to 1700°C. Amorphous and crystalline Si3 N4 were studied with additions of 4 to 17 wt% Y2 O3 and 4 wt% A12 O3 . Sintering occurs by a liquid-phase mechanism in which the kinetics exhibit the three stages predicted by Kingery's model. However, the rates during the second stage of the process are higher for all compositions than predicted by the model. X-ray data show the presence of several transient phases which, with sufficient heating, disappear leaving mixtures of β ' -Si3 N4 and glass or β '-Si3 N4 , α '-Si3 N4 , and glass. The compositions and amounts of the residual glassy phases are estimated. 相似文献
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Mats Carlsson Mats Johnsson Mats Nygren 《Journal of the American Ceramic Society》1999,82(8):1969-1976
Ta0.33 Ti0.33 Nb0.33 C and Ta0.33 Ti0.33 Nb0.33 C x N1− x whiskers were synthesized via a carbothermal vapor-liquid-solid growth mechanism in the temperature range 900°-1450°C in Ar or N2 . The optimum temperature was 1250°C. Whiskers were obtained in a yield of 70-90 vol%. The whiskers were 0.5–1 µm in diameter and 10–30 µm in length. The starting materials that produced the highest whisker yield were: TiO2 , Ta2 O5 , Nb2 O5 , C, Ni, and NaCl. C was added to reduce the oxides, and Ni to catalyze whisker growth. NaCl was used as a source of Cl for vapor-phase transportation of Ta and Nb oxochlorides and Ti chlorides to the catalyst. The catalyst metal was recycled several times during the synthesis and was transported as NiCl2 ( g ) according to thermodynamic calculations. The rate of formation and the chemical composition of the whiskers depended on the synthesis temperature, the choice of catalyst, and the atmosphere. At low temperatures, the whiskers were enriched in Nb and Ta, whereas the Ti content increased with increased synthesis temperature. 相似文献