共查询到20条相似文献,搜索用时 140 毫秒
1.
β晶型成核剂增韧聚丙烯研究 总被引:15,自引:3,他引:15
研究了取代苯酰 胺类的新型β成核剂对聚丙烯力学性能的影响。并采用偏光显微镜,差示扫描量热法和广角X衍射对β成核PP的结晶形态进行了详细的表征,结果表明,加入β成核剂后,由于具有独特束状结构β晶型的生成,PP的刚性略有下降,但韧性却得到了很大的提高。当成核剂用量为0.6%时,β晶型相对含量最高,悬臂梁缺口冲击强度达到最大值91.3J/m,约为纯PP的4倍。 相似文献
2.
综述了国内外聚丙烯β晶型成核剂合成方法的研发进展,比较了不同晶型成核剂的性能。目前主要的β晶型成核剂商品多为含亚酰胺键的化合物。 相似文献
3.
β晶型成核剂在聚丙烯中的应用 总被引:3,自引:0,他引:3
通过将聚丙烯原料和成核剂等助剂用高速搅拌机搅拌均匀后加入双螺杆冷拉挤出机组造粒,再用注塑机注塑出标准样条进行检测的办法分析比较加入β晶型成核剂后对聚丙烯性能的影响,结果发现在聚丙烯中加入β成核剂后,促进分子的结晶过程和加快结晶速度,使分子具有微晶结构,有利于PP产品的抗冲击强度、屈服强度、热变形温度的提高. 相似文献
4.
5.
6.
介绍了聚丙烯β晶型的特点,综述了聚丙烯β晶型成核剂的种类及其在聚丙烯应用上的研究进展,对聚丙烯β晶型成核剂的成核效果、作用机理等方面的研究进行了归纳。 相似文献
7.
本文论述了β晶型成核剂在均聚聚丙烯管材料中的应用,从加入量、改性后的效果,对比出性能的变化,在制成管材制品后,耐压测试达到聚丙烯热水管材国家标准要求. 相似文献
8.
聚丙烯的β晶型及β成核剂的研究进展 总被引:8,自引:1,他引:7
介绍了β晶型聚丙烯(β-PP)的性能及结构特点,重点介绍了4种重要的β晶型成核剂的特点、作用效果以及各种成核剂对聚丙烯性能的影响,并对当前β晶聚丙烯及β成核剂的研究状况和发展前景作了展望。 相似文献
9.
新型聚丙烯β晶型成核剂的制备及应用 总被引:1,自引:0,他引:1
吕志平;王卫星;张友强;万兆荣;薛建伟 《中国塑料》2009,23(7):81-84
利用正硅酸乙酯、硬脂酸和邻苯二甲酸钙制备了新型成核剂SLG1和SLG2。利用热分析考察了成核剂的热稳定性,采用X射线衍射分析(XRD)和偏光显微镜(PLM)对其改性聚丙烯(PP)的晶体形态进行了表征,采用差示扫描量热法(DSC)研究了其结晶行为,并测试了PP的力学性能。结果表明,成核剂SLG1和SLG2能够诱导β-PP的生成,使PP的结晶温度明显提高,并且加快了PP的结晶速率,但是降低了结晶度。成核剂使PP的晶粒明显细化,球晶之间的界面模糊。在SLG1和SLG2含量分别为0.15 %和0.3 t%时,PP的冲击强度分别由9.43 kJ/m2提高到了26.82 kJ/m2和37.79 kJ/m2。 相似文献
10.
β晶型成核剂改性聚丙烯纤维研究 总被引:4,自引:1,他引:4
研究了含 0 .2 5 %β晶型成核剂 (酰胺化合物 )的聚丙烯 Z3 0 S及其纤维的力学性能、晶型结构和微观形态。通过纺丝 -拉伸实验和力学性能测试、广角 X射线衍射分析、SEM观察 ,发现成核改性后生成了β晶型聚丙烯 (K值约为 75 .3 % ) ,抗冲性能大幅度提高。β晶型聚丙烯在纺丝卷绕过程中发生了β晶型→α晶型转变 ,纤维中产生约 10 %微孔隙 ,改性纤维的力学性能有所降低。 相似文献
11.
12.
13.
The influences of nucleating agent content on crystallization peak temperature, crystallization curve shape, crystallization onset temperature, and crystallinity of a copolypropylene were studied in detail by differential scanning calorimetry. The results showed that crystallization onset temperature and crystallization peak temperature increased 17°C–22°C and 15°C–19°C, respectively, with increasing nucleating agent content. The behavior of the nucleating agent showed excellent efficiency. But the shape of the crystallization curve broadened with increasing nucleating agent content, and the crystallinity came to an extremum when the nucleating agent content was 0.2%. These results generally differed from those for crystallization of i‐PP by a nucleating agent. Modification of copolypropylene was studied by use of a nucleating agent, and the characteristics of the effects of the nucleating agent on copolypropylene were mastered. The results showed that the hardness of a copolypropylene improved observably. So the abrasion resistance of biaxially oriented polypropylene (BOPP) film for cigarette packaging was improved by adopting the modified copolypropylene as the skin‐layer heat‐seal material of BOPP film. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101:3915–3919, 2006 相似文献
14.
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
15.
16.
17.
18.
The isothermal and nonisothermal crystallization kinetics of nonnucleated and nucleated isotactic polypropylene (iPP) were investigated by DSC and a polarized light microscope with a hot stage. Dibenzylidene sorbitol (DBS) was used as a nucleating agent. It was found that the crystallization rate increased with the addition of DBS. The influence of DBS on fold surface energy, σe, was examined by the Hoffman and Lauritzen nucleation theory. It showed that σe decreased with the addition of DBS, suggesting that DBS is an effective nucleating agent for iPP. Ozawa's theory was used to study the nonisothermal crystallization. It was found that the crystallization temperature for the nucleated iPP was higher than that for nonnucleated iPP. The addition of DBS reduced the Ozawa exponent, suggesting a change in spherulite morphology. The cooling crystallization function has a negative exponent on the crystallization temperature. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 2089–2095, 1998 相似文献
19.
20.
Supercritical carbon dioxide-assisted extrusion was adopted to prepare polypropylene containing aryl amide β nucleating agent. The experimental results showed that supercritical carbon dioxide did not affect the nucleating efficiency of β nucleating agent on polypropylene but acted as a carrier to facilitate the dissolution and self-assembly in polymer melts, so as to promote polypropylene crystallize into rich β-modification of needle-like crystals with outstanding toughening effect at low temperature. 相似文献