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1.
为了了解β晶型聚丙烯混杂复合体系的结构和性能,研究了β晶型聚丙烯在化学交联、添加纳米填料和热处理后的力学性能变化规律。结果表明5%~10%(wt)纳米CaCO3填料或2%(wt)交联剂与0.5%(wt)β晶型成核剂TMB共用时对聚丙烯有优良的增强、增韧效果;在80~150℃热处理温度范围内,加有05%(wt)TMB的聚丙烯在130℃时有最小的抗拉强度。经X衍射分析、差热分析证明在0.4%~0.8%(wt)TMB的用量范围内,对聚丙烯的β晶体的有序性和结晶效率影响不大,在0.5%(wt)成核剂TMB用量时,聚丙烯有最大的结晶度,130℃热处理可进一步提高聚丙烯β晶的结晶效率和总结晶度,结晶温度和熔融温度;加入纳米填料对β晶型聚丙烯的总结晶度和结晶效率影响不大,对有序性有较大的影响:而加入2%(wt)交联剂大大增加了总结晶度,同时大幅降低了β晶的有序度。偏光显微测试发现,纳米填料加入可降低球晶的尺寸和诱导纤维状的β晶形成。 相似文献
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聚丙烯/多壁碳纳米管复合材料的结晶行为 总被引:5,自引:0,他引:5
用溶液絮凝法制备了碳纳米管含量为0.5%~5%的聚丙烯(PP)/多壁碳纳米管(MWNT)复合材料。SEM研究表明MWNT在复合材料中呈纳米级分散。用DSC法研究了MWNT含量对PP非等温结晶性能的影响,发现MWNT作为PP的成核剂,使PP的结晶峰温向高温方向移动;由于MWNT对PP链段运动的阻碍作用,非等温结晶峰温并不随MWNT含量增加而增加;复合材料的结晶总速率均比纯PP大,但在碳纳米管含量0.5%~5%范围内随MWNT含量增加总速率反而降低;MWNT的加入对材料的结晶度影响不大,复合材料中PP的结晶晶型没有改变。当MWNT含量为0.5%时,观察到PP的球晶尺寸降低。 相似文献
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通过添加不同含量的粘土制备了三个不同类型(PP/DK1,PP/PPMA/DK1,PP/PPMA+DK1)纳米粘土/聚丙烯复合材料。通过对实验样品结晶性能的分析,结果表明:与纯聚丙烯结晶图相比,添加适量的粘土作为成核剂,能够使聚丙烯的球晶数量增多,球晶尺寸变小。同时增容剂(PPMA)的加入也会影响PP的结晶,使球晶尺寸不规整。 相似文献
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玻璃微珠填充PP复合材料力学性能与熔融结晶的研究 总被引:6,自引:0,他引:6
研究了玻璃微珠填充聚丙烯(PP)中玻璃微珠含量及粒径大小对复合材料力学性能和熔融、结晶行为的影响。结果表明:填充体系随着玻璃微珠含量增加,拉伸强度增加,冲击强度降低。在相同条件下,小粒径微珠填充体系拉伸强度和冲击强度均高于大粒径微珠填充体系。玻璃微珠在PP中具有成核作用,PP以异相成核方式结晶,提高了PP的结晶温度,结晶速率增大,流动性先增加后降低。 相似文献
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《现代塑料加工应用》2016,(6)
采用稀土钛偶联剂对空心玻璃微珠进行表面改性,通过熔融共混挤出法制备了聚丙烯(PP)/空心玻璃微珠复合材料,研究了复合材料的力学性能和结晶性能。结果表明,经过稀土钛偶联剂表面改性的空心玻璃微珠与PP的界面结合力显著提高,提升了复合材料的力学性能,并且使PP的结晶度增大。 相似文献
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聚丙烯/聚苯乙烯/膨润土共混体系的结晶性能和热性能研究 总被引:1,自引:1,他引:0
通过偏光显微镜(PLM)和光学解偏振仪对聚丙烯/聚苯乙烯/膨润土三元共混体系的结晶形态和等温结晶速率进行了研究。结果表明:共混体系所形成的球晶比纯聚丙烯(PP)所形成的球晶尺寸小,聚苯乙烯(PS)/膨润土(Garamite)复合粒子的加入导致PP的结晶成核和生长发生了改变,加快了PP的结晶速率。同时采用差示扫描量热仪(DSC)对该三元共混体系的热性能进行了研究,结果表明,随着膨润土含量的增加,共混体系熔融温度变高,结晶温度变高,结晶度下降。 相似文献
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用差示扫描量热仪、偏光显微镜和广角X射线衍射仪研究了高性能热塑性弹性体苯乙烯、乙烯支化异戊二烯三嵌段共聚物(HYBRAR)及α成核剂与聚丙烯(PP)共混物的结晶性能及形态.结果表明:HYBRAR对PP有一定的成核作用,并使其球晶界面变得模糊;在一定温度范围内,温度愈低PP结晶速率愈快,结晶越不完善;α成核剂的加入细化了PP的球晶,提高了结晶速率和结晶度,但对其晶型没有影响. 相似文献
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利用单螺杆挤出机在稳定的温度和转速下挤出聚丙烯(Polypropylene,PP)/玻璃微珠(Glassbeads,GB)复合材料,结合目标检算法定义了玻璃微珠的等效粒径,通过数学关系计算出玻璃微珠的实际填料含量,并分析了填料粒径、填料含量对组分含量测量结果的影响。结果表明机器视觉在线测量组分含量结果的平均相对误差为0.054,与离线灰分法测量结果相近,玻璃微珠的填料粒径越大、含量越低,机器视觉测量组分含量的结果越准确。 相似文献
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田瑶珠;王松;秦军;罗筑;于杰 《中国塑料》2010,24(12):98-101
用差式扫描量热仪和偏光显微镜研究了分散剂对聚丙烯(PP)和松香成核PP的非等温结晶行为,并比较了它们的透明性能。结果表明,不同的分散剂对PP和松香成核PP的结晶行为影响不一样,分散剂A和分散剂C能提高松香成核PP的结晶温度、结晶速率和结晶初始速率,能显著降低其球晶尺寸提高其透明性;而分散剂B不能提高松香成核PP的结晶速率和结晶初始速率,不能降低其球晶尺寸,对松香成核PP的透明性提高没有作用。 相似文献
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Zhidan Lin Baofeng Xu Zixian Guan Chao Chen 《Journal of Industrial and Engineering Chemistry》2013,19(3):926-931
It has been observed that the formation of β-crystal is suppressed when β-polypropylene (β-PP) is blended with crystalline polymers, but the reason is still uncertain. In this study, we investigated the influence of the crystallization conditions of polytrimethylene terephthalate (PTT), such as melt crystallization, cold crystallization, isothermal crystallization temperature, and crystallization time on the β-nucleation behavior of PP phase in the β-PP/PTT blends. The results showed that the β-crystal content of PP phase in the blends decreases with increasing of PTT content. Cold crystallization of PTT would mainly induce the formation of α-crystal in PP component, whereas melt crystallization would induce the formation of β-crystal PP in their blends. The degree of crystallinity of PTT increases by improving the crystallization temperature or extending the time of crystallization, which leads to the production of more α-crystal in PP component. This means that the second component could inhibit the formation of β-crystal in PP. 相似文献
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Effect of dispersion morphology, resulting from different mixing sequences used in making ternary composite polypropylene (PP)/poly(dimethylsiloxane) (PDMS)/nano SiO2, on the crystallization of PP phase is studied. Mixing sequence is found to have significant effect on the dispersion morphology of the ternary composite, which in turn affected the crystallization of the PP matrix of the ternary composite. Crystallization behaviour of PP, studied by the differential scanning calorimetry, is discussed for the effect of different dispersion morphologies on overall crystallization process rate, nucleation rate, crystal size distribution and crystallinity. 相似文献
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LMPM/PP复合材料中PP的晶型结构 总被引:8,自引:2,他引:6
用宽角X射线衍射(WAXD)研究低熔点金属(LMPM)/PP复合材料中的PP的晶型结构,结晶度β晶型含量以及α-晶型的微观尺寸,发现LMPM用量增加,LMPM粒径减小,加和偶联剂以及提高混炼转速有利于PP形成β-晶型,并使α-晶型的微观尺寸变小,但结晶度变化不大,这种规律归结于LMPM的异相成核作用以及复合材料在冷却时内部大的温度新梯度。 相似文献
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在聚丙烯(PP)中加入两种新型成核剂:二苄叉山梨醇衍生物YS-688(α成核剂)和芳酰胺类化合物TMB-5(β成核剂),通过密炼–挤出的方法制备了PP/成核剂共混物材料。通过偏光显微镜、X射线衍射、差示扫描量热和力学性能测试研究了这两种成核剂对共混物结晶和力学性能的影响。结果表明,两种成核剂在适量时均能提高PP的结晶速率和结晶度,细化晶粒,且使晶体界面模糊,其中TMB-5具有较强的诱导PPβ晶成核的能力,当其质量分数为0.075%时,可使PP形成树枝状的β晶,而YS-688未改变PP的晶型,只生成了α晶。YS-688可提高共混物的拉伸强度,而TMB-5对共混物的拉伸强度影响很小;当两种成核剂质量分数均为0.075%时,共混物的韧性最好,相对于纯PP,PP/YS-688共混物的常温和–30℃缺口冲击强度分别提高了37.41%和12.76%,拉伸强度提高了11.11%;PP/TMB-5共混物的常温和–30℃缺口冲击强度分别提高了100%和55.41%。 相似文献
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以自制的剥离高岭(MK)、原高岭土(K)以及聚丙烯(PP)和马来酸酐接枝聚丙烯(PP-g-MA)等作为基本原料,通过熔融挤出、注塑成型,制备PP复合材料。采用XRD、DSC、TG研究复合材料的非等温结晶行为、结晶动力学以及热降解性能。结果表明:高岭土的加入,使结晶温度、结晶度、热稳定性都有所提高,且结晶速率加快,具有异相成核作用。与原高岭土相比,改性高岭土更能促进PP复合材料的PP异相成核,促进PP稳态晶型(α晶型)的转变,结晶速率较快。与纯PP和PP/PP-g-MA复合材料相比,PP/改性高岭土复合材料的结晶峰温度、最大热降解温度分别提高了16.7、7.8、9.7、12.6℃。 相似文献
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Nan-ying Ning 《Polymer》2007,48(25):7374-7384
In this work, halloysite nanotubes (HNTs), a new type of inexpensive filler, were used for the modification of polypropylene (PP). HNTs were first surface treated by methyl, tallow, bis-2-hydroxyethyl, quaternary ammonium, then melt mixed with PP. Scanning electron microscope (SEM) was used to examine the dispersion of HNTs in PP matrix. Differential scanning calorimetry (DSC), polarized light microscope (PLM), dynamic melt rheometry and wide angle X-ray diffraction (WAXD) were employed to investigate the crystallization behavior of the prepared PP/HNT composites. The mechanical properties were evaluated by Instron and impact tests. SEM results revealed that HNTs could be well-dispersed in PP matrix and had a good interfacial interaction with PP, even up to a high content of 10 wt%. DSC data indicated that HNTs could serve as a nucleation agent, resulting in an enhancement of the overall crystallization rate and the non-isothermal crystallization temperature of PP. PLM showed a constant spherulite growth rate and a decreased spherulite size at given isothermal crystallization temperature, suggesting that nucleation and growth of a spherulite are two independent processes. The result obtained by dynamic melt rheometry indicated that HNTs mainly promoted nucleation and had not much influence on the growth of PP crystallization. Nevertheless, by fast cooling the samples, almost constant spherulite size can be obtained for both pure PP and PP/HNT composites due to the limited nucleation effect of HNTs on PP crystallization. WAXD showed that HNTs mainly facilitated α-crystal form of PP. Though a good dispersion of HNTs in PP matrix was observed, out of our expectation, not much enhancement on mechanical properties of PP/HNT composites had been achieved, and this could be mainly ascribed to the constant crystallinity and spherulite size of PP as well as the small length/diameter ratio of HNTs. 相似文献
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采用熔融共混法,制备了聚酰胺6/氯化钙(PA6/CaCl2)复合材料。通过差示扫描量热法(DSC)、X射线衍射法(XRD)研究了PA6基体在受限条件下的非等温结晶及晶型转变行为。结果表明:金属离子Ca2+与酰胺基团的络合配位作用使PA6/CaCl2复合材料中PA6的结晶行为和结晶度受到了限制。随着CaCl2含量的增加,PA6的结晶度、结晶峰温度、熔融峰温度逐渐降低,结晶速率减小,结晶半峰宽增大,当CaCl2的含量大于8%时,PA6变为无定形态;此外,CaCl2的引入有利于PA6中α晶的生成。 相似文献
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Hai Huang Bing Han Lei Wang Ning Miao Hong Mo Ning‐Lin Zhou Zhen‐Mao Ma Jun Zhang Jian Shen 《应用聚合物科学杂志》2011,119(3):1516-1527
The subject of this study was the crystallization behavior and thermal properties of polypropylene (PP)/maleic anhydride (MAH) modified nano calcium carbonate (nano‐CaCO3) composites. In this study, 5 wt % nano‐CaCO3 modified with different contents of MAH was filled into a PP matrix. X‐ray diffraction and differential scanning calorimetry were used to characterize the crystal morphology and crystallization kinetics of a series of composites. The results demonstrate that the nano‐CaCO3 modified with MAH had an important effect on the thermal and morphological properties of the nanocomposites. The Avrami exponent of the pure PP was an integer, but those of the composites were not integers, but the crystallization rate constant decreased as the content of MAH in the nano‐CaCO3 filler increased in isothermal crystallization. In nonisothermal crystallization, the kinetic parameter F(T) and the degree of crystallinity of pure PP were compared with those of the PP composites filled with nano‐CaCO3. We suggest that heterogeneous nucleation existed in the PP composites and that the transformation and retention of the β‐form crystal into the α‐form crystal took place in the composite system and the β‐form crystal had a higher nucleation rate and growth process than the α‐form crystal in the PP composites. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 相似文献