首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到18条相似文献,搜索用时 140 毫秒
1.
朱德钦  生瑜  童庆松  王真 《应用化学》2014,31(8):885-891
在转矩流变仪中用熔融接枝法制备马来酸酐(MAH)和苯乙烯(St)接枝聚丙烯(PP)—PP-g-(MAH/St)和PP-g-MAH,将其作为聚丙烯/木粉复合材料的相容剂。FTIR证实MAH和St单体与PP发生接枝反应。用SEM和DSC等手段考察两种相容剂对PP/木粉复合材料微观形貌和结晶性能的影响,探索了各种PP/木粉复合材料加工和力学性能不同的内在原因。SEM显示,PP-g-(MAH/St)改性木粉比PP-g-MAH改性木粉在PP基体中分散性更佳,木粉与PP的界面更加模糊,相容性进一步改善。DSC结果表明,PP-g-(MAH/St)改性体系可增强木粉对PP的异相成核作用,提高结晶温度和结晶度。复合材料的加工和力学性能测试结果表明,PP-g-(MAH/St)改性效果明显优于PP-g-MAH。复合材料的熔体质量流动速率随相容剂用量的增加而逐步下降,PP-g-(MAH/St)改性体系拉伸强度和弯曲强度却逐步上升,并在相容剂用量为4.8 g/100 g PP时达到极值。此时其拉伸强度达40.62 MPa,分别是未改性体系和PP-g-MAH改性体系的1.29和1.17倍;其弯曲强度达45.72 MPa,分别是未改性体系和PP-g-MAH改性体系的1.23和1.59倍;而无缺口冲击强度却在相容剂用量为3.6 g/100 g PP时达到极值13.35 kJ/m2,分别是未改性体系和PP-g-MAH改性体系的1.62倍和1.42倍。  相似文献   

2.
大分子相容剂改性Mg(OH)2/PP阻燃材料的性能   总被引:1,自引:0,他引:1  
用双螺杆挤出机熔融挤出法制备了相容剂改性氢氧化镁/聚丙烯[Mg(OH)2/PP]阻燃材料。研究了马来酸酐接枝聚丙烯(PP-g-MA),马来酸酐接枝(乙烯/辛烯)共聚物(POE-g-MA)和马来酸酐接枝聚醋酸乙烯酯(EVA-g-MA)3种大分子相容剂对阻燃材料的熔体流动性、结晶行为、力学性能和断口形态的影响。结果表明:相容剂PP-g-MA和POE-g-MA的加入使阻燃材料的熔体流动速率降低,PP结晶温度提高,EVA-g-MA的加入使阻燃材料熔体流动速率数提高;Mg(OH)2对PP结晶存在异相成核作用,Mg(OH)2的加入使PP的冲击强度、拉伸强度和断裂伸长率降低,杨氏模量提高;相容剂改性后Mg(OH)2/PP阻燃材料的拉伸强度提高,其中以PP-g-MA最为明显,而POE-g-MA则提高了阻燃材料的冲击强度。  相似文献   

3.
采用熔体共混的方法制备了两种增容剂增容的聚酰胺1010/聚丙烯(PA1010/PP)共混物,通过扫描电镜(SEM)、力学性能和差示扫描量热(DSC)测试,对动态保压注射成型(动态)和普通注射成型(静态)中增容剂POE-g-MAH(马来酸酐接枝乙烯-辛烯共聚物)和PTW(乙烯-丙烯酸丁酯-甲基丙烯酸缩水甘油酯共聚物)对PA1010/PP共混物的增容作用进行了比较研究.研究结果表明,普通注射成型中,PTW增容体系具有更小的分散相粒子,在DSC测试中出现两个结晶峰,即出现异相成核结晶和均相成核结晶,具有更好的拉伸和冲击性能,增容作用更佳.动态保压注射成型中施加剪切可以提高所有共混物的拉伸强度、拉伸模量和缺口冲击强度,PTW和POE-g-MAH两种增容剂增容体系冲击性能相近,但POE-g-MAH增容体系的分散相相区尺寸减小明显、分布均匀性显著增加,材料冲击强度增加幅度更大,表明剪切更有利于POE-g-MAH增容作用的进行.两种增容剂增容作用的不同源于它们化学组成的不同引起的材料形态差别.  相似文献   

4.
采用偏光显微镜和相差显微镜详细研究PP/PMMA不相容聚合物共混物体系和PP/PMMA/PP-g-PMMA增容共混体系的结晶和相形态.偏光显微照片的研究结果表明,增容剂PP-g-MAH中PP结晶需要克服更多的能垒,导致PP结晶形态变得不完善,球晶尺寸变小.比较PP/PMMA和PP/PMMA/PP-g-MAH的相差显微照片可以看出,由于增容剂的加入,PP与PMMA相之间的界面变得模糊,两相的相容性变好.随着PP-g-MAH中MAH接枝率的增加,PMMA分散相的尺寸减小且变得均匀;当增容剂的接枝率为2.41%,添加的质量分数为4.71%,PP/PMMA共混体系中PMMA分散相的相?尺寸可达最小.PP-g-MAH作为反应型增容剂,一方面与PP在界面区域产生共晶;另一方面,MAH极性基团与PMMA的极性基团间产生的强的化学键合作用,使得界面区域的PP-g-MAH分子采取有利于降低构象熵的构象来起到增容作用.PP/PMMA共混物在130℃等温结晶的结果显示,PMMA相对PP的结晶形态的影响较小,PP结晶呈现典型的均相成核特征.PP/PMMA共混体系中加入PP-g-MAH,PP结晶尺寸减少.与非等温结晶相比,等温结晶的PP/PMMA共混物中PMMA相区尺寸明显偏大.  相似文献   

5.
GMA/苯乙烯多组分单体接枝聚丙烯结晶行为研究   总被引:8,自引:0,他引:8  
使用差示扫描量热计 (DSC)研究了甲基丙烯酸缩水甘油酯 苯乙烯 (GMA St)多单体熔融接枝聚丙烯[PP g (GMA co St) ]的等温和非等温结晶行为 ,用偏光显微镜观察了结晶的形态 ,并利用Avrami方程对其结晶动力学进行了分析 .研究发现接枝聚丙烯的结晶模式与PP相似 ,属于异相成核控制的球晶三维生长 ;但接枝聚丙烯的结晶温度 (Tc)显著提高 ,幅度高达 16~ 19℃ ,总结晶速率与纯PP相比明显加快 .接枝聚丙烯上GMA co St支链的存在 ,降低了成核界面自由能 ,促进了聚丙烯结晶的异相成核 .在接枝率不太高的情况下 ,随着接枝率的提高 ,接枝聚丙烯的结晶温度升高 ,总结晶速率加快 .在高接枝率范围内 ,随着接枝率的提高 ,接枝PP的Tc 不再升高 ,且由于接枝链的增长严重阻碍了球晶生长 ,导致接枝PP的总结晶速率反而随接枝率的升高而下降  相似文献   

6.
马来酸酐接枝热塑性弹性体在PP/PA6共混物中的作用   总被引:10,自引:0,他引:10  
研究了马来酸酐接枝热塑性弹性体 (TPEg )作为增容剂对聚丙烯 (PP) 尼龙 6 (PA6 )共混体系的相容性、相态以及物理力学性能的影响 .研究结果表明TPEg的加入大大改善了PP PA6共混体系的相容性 ,且随TPEg含量的增大分散相粒径明显降低 ,共混物的韧性以及延展性大大提高 ,同时拉伸强度及模量仍保持较好的水平 .TPEg增容的PP PA6共混物的非等温结晶行为的研究表明 ,共混物中PP和PA6的结晶行为不同于各自纯的聚合物 ,PA6作为成核剂使PP的结晶温度提高 ;而PA6由于TPEg的加入 ,出现分级结晶现象 ,一级结晶温度略低于纯PA6的结晶温度 ,且随TPEg含量增大结晶受阻 ,二级结晶温度与PP的接近 .由于PP、PA 6以及TPEg之间存在较强的相互作用 ,三元共混物中PP及PA6的玻璃化转变温度分别较其纯聚合物升高 .基于上述结果 ,提出了本共混体系的结构模型  相似文献   

7.
以马来酸酐(MAH)、聚丙烯蜡(PPW)为主要原料,采用原位固相接枝改性法制得PP/CaCO3-MAH-PPW复合材料,并与添加相容剂聚丙烯接枝马来酸酐(PP-g-MAH)所制得的PP/PP-g-MAH/CaCO3复合材料进行比较。结果表明,CaCO3良好的分散性及其与PP基体适宜的界面粘接是复合材料具有较好韧性的关键因素。与PP/PP-g-MAH/CaCO3复合材料相比,PP/CaCO3-MAH-PPW复合材料表现出更佳的冲击、弯曲和加工性能,当m(PP)∶m(CaCO3)=100∶20时,材料缺口冲击强度达到最大值,是基体树脂的1.19倍。  相似文献   

8.
官能团化聚丙烯对Mg(OH)2/PP结晶与熔融行为的影响   总被引:7,自引:1,他引:6  
制备了官能团化聚丙烯改性Mg(OH)2/PP复合材料,并用DSC研究了改性PP,Mg(OH)2/PP和改性Mg/(OH)2/PP中PP的结晶与熔融行为,官能团化PP(FPP),丙烯酸(AA)和Mg(OH)2都能提高PP的结晶温度,归结于异相成核作用,AA和FPP加入进一步使Mg(OH)/PP中PP结晶温度提高,但AA用量增加对PP结晶温度无影响。  相似文献   

9.
PTW对PA1010/PP共混物的增容作用   总被引:2,自引:0,他引:2  
为了增加聚酰胺1010/聚丙烯(PA1010/PP)共混物的相容性,提高共混物的力学性能,采用一种新型的反应型增容剂乙烯-丙烯酸丁酯-甲基丙烯酸缩水甘油酯共聚物(PTW)进行增容,通过扫描电镜(SEM)、力学性能、傅里叶变换红外光谱(FTIR)和差示扫描量热(DSC)测试,研究了PTW对PA1010/PP共混物的增容作用.结果表明,随着PTW的加入,共混物的相区尺寸明显变小,当PA1010/PP/PTW质量比为70∶30∶7时,分散相尺寸细小而均匀,表明PTW有较好的增容作用.FTIR结果表明,PTW上的环氧基团和PA1010在熔融共混中发生了化学反应.DSC研究结果表明,PA1010的结晶温度随PTW的加入而降低,说明PTW对PA1010结晶有抑制作用.另外,PTW的加入使PP的结晶温度下降,当PTW质量分数为5%时出现2个结晶峰,即出现异相成核结晶和均相成核结晶,PP均相成核结晶的出现从另一个方面说明,在PA1010基体中分散相PP尺寸非常细小.当PTW质量分数为7%时共混物的力学性能最佳,干态冲击强度达到13.93kJ/m2,是未加增容剂时的2倍,拉伸和弯曲性能基本不变.PTW的增容机理在于其分子链中的甲基丙烯酸缩水甘油酯能与PA1010发生化学反应,而乙烯链段与PP有较好的亲和性,从而降低界面张力,减少相区尺寸,大幅度提高力学性能.  相似文献   

10.
通过将不同改性的高岭土与聚丙烯共混, 制备了聚丙烯插层的PP/高岭土纳米复合材料. 并通过X射线衍射分析(XRD)、透射电子显微镜(TEM)研究了复合材料的微观结构, 同时通过差示扫描(DSC)非等温结晶方法和偏光显微镜(PLM)照片, 研究了改性高岭土母粒对聚丙烯的结晶性能的影响. 采用Avrami方程式及Jeziorny修正过的Avrami的方程式对PP/高岭土的非等温结晶动力学进行了研究. 结果表明, 有机改性过的高岭土可被聚丙烯完全剥离, 在XRD谱图中, 高岭土的001峰不可见, 在TEM中可见剥离的片层. 同时随着改性高岭土的加入, 使得聚丙烯异相成核结晶增长, 且填充聚丙烯的最快结晶温度在395K. 结果也表明, 有机改性的高岭土能有效促进PP的异相成核, 提高PP的结晶速率和结晶温度, 但对结晶速率常数影响不是很大.  相似文献   

11.
Dang  Li  Nai  Xue-ying  Liu  Xin  Zhu  Dong-hai  Dong  Ya-ping  Li  Wu 《高分子科学》2017,35(9):1143-1155
The effects of maleic anhydride-grafted polypropylene(PP-g-MAH) and maleic anhydride-grafted polyolefin elastomer(POE-g-MAH) on interfacial adhesion properties of the polypropylene/magnesium oxysulfate whiskers(PP/MOSw) composites were investigated via mechanical, thermal, ATR-FTIR and rheological tests. Although significant increases in yield strength and Young's modulus were observed in PP-g-MAH treated composites, a sharp decline in these properties was observed in POE-g-MAH treated composites. ATR-FTIR results indicated that esterification occurred between the hydroxyl groups of MOSw and the carbonyls of anhydrides of both compatibilizers but POE-g-MAH was still incompatible with the PP matrix, as verified by the presence of shoulder peaks in DTG curves and numerous voids in SEM micrographs. On the other hand, PP-g-MAH was highly compatible with the PP matrix, as evidenced by the peaks in DTG curves and vague interfaces with wrapped melts on the surface of MOSw. Rheological behaviors also confirmed that introducing PP-g-MAH resulted in a transition from liquid-like to solid-like, which was attributed to the stronger interfacial adhesion between MOSw and the PP matrix. POE-g-MAH treated composites, in contrast to PP-g-MAH, maintained liquidlike rheological behaviors as typical molten polymers. There is likely a MOSw network formed in the PP/15PP-gMAH/15 MOSw composite as suggested by the significant deviation of G′ versus G″ plots and the two crossover frequencies observed in plots of tan? versus frequency.  相似文献   

12.
The effect of different interfacial interaction on the crystallization and melting behavior of PP/nano-CaCO3 composites was investigated using differential scanning calorimetry, X-ray diffraction and polarized optical microscope. The results indicated that nano-CaCO3 acted as heterogeneous nuclei for PP crystallization. There existed a synergistic effect of heterogeneous nucleation between nano-CaCO3 and compatibilizer for PP crystallization, which was proved by increasing the crystallization rate and decreasing the fold surface free energy as well as favoring the formation of β-crystal of PP. However, this synergistic effect was dependent on the interfacial interaction between PP and compatibilizer. The increased miscibility between compatibilizer and PP favored this synergistic effect.  相似文献   

13.
PP/PP-g-MAH/PA6共混物结构与可纺性研究   总被引:3,自引:0,他引:3  
运用DSC、SEM、纺丝成形等手段研究了增容剂聚丙烯接枝马来酸酐 (PP g MAH)对聚丙烯 聚酰胺 6(PP PA6 )共混物结构和性能的影响 .结果表明 ,共混物呈典型海岛型两相结构 ;增容剂PP g MAH与PA6之间的在位反应改善了PP PA6共混体系的相容性 ,使共混物中PA6的热结晶峰消失 ,PP的结晶生长速率和成核速率降低 ,可纺性提高  相似文献   

14.
The melt-direct intercalation method was employed to prepare polypropylene (PP)/maleic anhydride grafted polypropylene (PP-g-MAH)/organic-montmorillonite (Org-MMT), X-ray diffractometer was used to investigate the intercalation effect and crystallite size in composites and TEM micrograph to observe the dispersion of Org-MMT interlayers in polypropylene. The results showed that by introducing maleated polypropylene in PP/Org-MMT composite, macromolecule segments had intercalated into interlayer space of Org-MMT. As a result, Org-MMT interlayers were dispersed evenly in polypropylene and PP/PP-g-MAH/Org-MMT nanocomposite was synthesized. The crystallite size of nanocomposite perpendicular to the crystalline plane such as (0 4 0), (1 3 0), (1 1 1), (0 4 1) is smaller than that of pristine PP, which indicated that the crystallite size of PP in nanocomposite can be diminished by adding PP-g-MAH and Org-MMT in PP. Moreover, the nonisothermal crystallization kinetics of PP and PP/PP-g-MAH/Org-MMT nanocomposite was investigated by differential scanning calorimetry (DSC) with various cooling rates. The Avrami analysis modified by Jeziorny, Ozawa method and a method developed by Liu were employed to describe the nonisothermal crystallization process of these samples. The difference in the exponent n between PP and nanocomposite, indicated that nonisothermal kinetic crystallization corresponded to tridimensional growth with heterogeneous nucleation. The values of half-time, Zc, F(T) and K(T) showed that the crystallization rate of composites was faster than that of PP at a given cooling rate.  相似文献   

15.
非等温结晶动力学;聚丙烯/聚(丙烯-g-马来酸酐)/蒙脱土纳米复合材料结晶动力学研究  相似文献   

16.
《European Polymer Journal》2007,43(5):1660-1671
The physical and thermal properties of nanoclay filled nylon 6 (nano-nylon 6) blended with poly(acrylonitrile–butadiene–styrene)terpolymers (ABS) were investigated using metallocene polyethylene grafted maleic anhydride (POE-g-MA) or polybutadiene grafted maleic anhydride (PB-g-MA) as a compatibilizer. Cooling conditions significantly affected the crystalline structure of nano-nylon 6. No clear effect of both compatibilizers on the dispersion of clay has been observed via transmission electron microscope analysis. Through morphology observation, the ABS particle sizes tended to decrease with the addition of compatibilizers, especially in PB-g-MA cases, suggesting a good interfacial bonding between nano-nylon 6 matrix and ABS dispersed phase. Non-isothermal crystallization results indicated that the crystallization temperatures slightly changed with increasing content of compatibilizers. In addition, melting behaviors with different crystal forms varied widely with cooling conditions. The crystallization kinetics under isothermal conditions reflected that introduced compatibilizers impeded the growth rate, especially for PB-g-MA compatibilized system.  相似文献   

17.
Attempts have been made to evaluate the effect of interface and degree of interfacial interaction upon electrical conductivity threshold in polypropylene/expanded graphite (PP/EG) nanocomposites, and dispersion state of graphite nanosheets. For this purpose, maleic anhydride grafted polypropylene (PPgMA) and maleic anhydride grafted EPDM (EPDMgMA) were used as compatibilizer. Nanocomposite samples containing 1–5 vol% of EG were prepared by melt mixing method using laboratory scale internal mixer. Characterization was carried out by using X‐ray diffraction (XRD), differential scanning calorimeter (DSC), thermo‐gravimetric analysis (TGA), scanning electron microscope (SEM), transmission electron microscope (TEM), and rheo‐mechanical spectroscopy (RMS). The conductivity measurements were carried out by using four point probe method according to ASTM D991. Results showed that the conductivity threshold is controlled by the extent of interfacial interaction between PP and EG. So, better conductivity was obtained using PPgMA as compatibilizer which causes higher level of interaction between PP and EG, and therefore better dispersion of the EG nanolayers in the polymer matrix. On the other hand, high levels of compatibilizers, especially EPDMgMA, caused formation of separated aggregates of EG shelled with the compatibilizer, which results in the reduction of conductivity of the nanocomposites. This finding has been verified by SEM, RMS, and conductivity measurements. Effects of EG nanolayers on crystalline structure and thermal decomposition temperature of the nanocomposites have also been investigated by DSC and TGA, respectively. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

18.
采用马来酸酐接枝聚丙烯(PP-g-MAH)对聚丙烯/聚对苯二甲酸乙二酯(PP/PET)共混体系进行增容,研究了增容前后复合体系的相形态和流变行为的变化.结果表明,共混体系中当PP组分为分散相时,增容剂能够显著减小PP液滴尺寸,使其形状松弛时间减小,变形与破裂的剪切敏感性降低;当共混体系两组分配比处于临界相反转点周围时,增容剂则会导致其内部部分双连续与“海-岛”结构共存的复杂相形态消失,低频区模量频率依赖性的增加表明体系内部界面结合程度的增加;而当共混体系中的PET组分为分散相时,增容剂的引入对体系结构流变学影响较小,表明增容效果不大.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号