Synthesis and characterization of polyethylene‐octene elastomer/clay/biodegradable starch nanocomposites

The aim of this work is the production of new nanocomposites from metallocene polyethylene‐octene elastomer (POE), montmorillonite and biodegradable starch by means of a melt blending method. Characterizations of clay, modified clay, POE, POE‐g‐AA, and the hybrids produced from polymer, clay, and/or starch were performed by X‐ray diffraction (XRD) spectroscopy, Fourier transform infrared (FTIR) spectrophotometer, differential scanning calorimetry (DSC), thermogravimetry analyzer (TGA), scanning electron microscope (SEM), and Instron mechanical tester. As to the results, organophilic clay can be well dispersed into acrylic acid grafted polyethylene‐octene elastomer (POE‐g‐AA) in nanoscale sizes since cetyl pyridium chloride is partially compatible with POE‐g‐AA and allows POE‐g‐AA chains to intercalate into clay layers. Based on consideration of thermal and mechanical properties, it is also found that 12 wt % of clay content is optimal for preparation of POE‐g‐AA/clay nanocomposites. The new partly biodegradable POE‐g‐AA/clay/starch hybrid could obviously improve the elongation and the tensile strength at break of the POE‐g‐AA/starch hybrid since the former can give the smaller starch phase size and nanoscale dispersion of silicate layers in the polymer matrix. The nanocomposites produced from our laboratory can provide a stable tensile strength at break when the starch content is up to 40 wt %. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 397–404, 2005     

密度和黏结性可控的PE/POE/CaCO3体系颗粒流道调整剂的制备

采用聚乙烯（PE）、聚烯烃弹性体（POE）和碳酸钙（CaCO₃）共混制备了聚合物类颗粒流道调整剂,考察了不同CaCO₃含量和PE与POE比例条件下的PE/CaCO₃、POE/CaCO₃、PE/POE/CaCO₃三类颗粒流道调整剂的密度、熔点熔程、黏结性能、力学性能差异。结果表明,颗粒流道调整剂的密度随CaCO₃含量增加而增大,实现了1.05~1.20 g/cm³范围内可调;结合PE的熔融特性和POE的黏结性能,实现了黏结性能由PE/CaCO₃共混物熔融黏结转为POE/CaCO₃、PE/POE/CaCO₃体系软化黏结的可控调节;通过调节CaCO₃含量、PE与POE比例可以改变流道调整剂颗粒的熔点熔程和拉伸强度,相同CaCO₃含量时PE/POE/CaCO₃体系颗粒的拉伸强度随PE含量升高而增大。     

Crystallization behavior and mechanical properties of polypropylene random copolymer/poly(ethylene‐octene) blends

New polymer blends of polypropylene random copolymer (PP‐R) and poly(ethylene‐octene) (POE) were prepared by melt‐blending process using a corotating twin‐screw extruder. The POE content was varied up to 35%. The toughening efficiency of POE for PP‐R was evaluated by the mechanical properties of the resulted PP‐R/POE blends. The crystallization behavior and morphology of the blends were also studied. Results show that POE acts as nucleation agent to induce the crystallization of PP‐R matrix at higher crystallization temperature. Super‐toughened PP‐R/POE blends (Izod impact strength more than 500 J/m) can be readily achieved with only 10 wt % of POE. The high toughness of PP‐R/POE is attributed to cavitation and shear yielding of matrix PP‐R, as revealed by the morphology studies. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

The mechanical and rheological behavior of the PA/TPU blend with POE‐g‐MA modifier

In this research, we attempt to improve the impact strength and the viscosity of PA (polyamide) by blending two elastomers, TPU (thermoplastic polyurethane) and POE‐g‐MA (maleic anhydride‐grafted polyethylene‐octene elastomer), in PA matrix with twin screw extruder. The ratio of blending is 80PA/20TPU and 80PA/20TPU/20POE‐g‐MA (66.66PA/16.67TPU/16.67POE‐g‐MA). Results indicate that POE‐g‐MA improves the low viscosity of PA and TPU during the blending process, and also their compatibility. Thus, the 80PA/20TPU/20POE‐g‐MA blend has better tensile stress and elongation than 80PA/20TPU blend, and furthermore POE‐g‐MA significantly improves the impact strength of PA, even to super‐toughness grade. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Polyamide-6/Poly(lactic acid) Blends Compatibilized by the Maleic Anhydride Grafted Polyethylene-Octene Elastomer

To evaluate the feasibility of a strategy to partially replace polyamide-6 (PA6) with poly(lactic acid) (PLA), the morphology, mechanical, and thermal properties of PA6/PLA blending systems were investigated. Polyethylene-octene elastomer (POE) and POE grafted with maleic anhydride (POE-g-MAH) are added to improve the impact strength and elongation at break of the blend. The results show that POE-g-MAH is an effective compatibilizer for PA6/PLA blending system. Compared with the morphology of PA6/PLA/POE, smaller particle size, more homogeneous distribution of domains and improved interfacial adhesion between matrix and domains were observed in the PA6/PLA/POE-g-MAH blending system.     

High impact poly(lactic acid)/poly(ethylene octene) blends prepared by reactive blending

Poly(ethylene octene) grafted with glycidyl methacrylate (POE‐g‐GMA) was prepared and used to toughen poly (lactic acid) (PLA) via reactive blending. It was found that the notched Izod impact strength of PLA/POE‐g‐GMA blends improved dramatically when the content of elastomer was higher than 10 wt%. Reactive compatibilization between PLA and POE‐g‐GMA were studied by Fourier transform infrared spectroscopy (FTIR) and “Molau test,” the results showed the end carboxyl groups of PLA reacted with the epoxide groups of POE‐g‐GMA during blending. This considerably improved the compatibilization, leading to better wetting of the dispersed phase by the PLA matrix and finer dispersed POE‐g‐GMA particles with narrow distribution. Moreover, the critical interparticle distance (L_c) of the dispersed domains for PLA/POE‐g‐GMA blends system at room temperature was also identified. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers     

Process analytical technology applied for end-point detection of pharmaceutical blending by combining two calibration-free methods: Simultaneously monitoring specific near-infrared peak intensity and moving block standard deviation

Here, we describe a combination approach using Two Calibration-Free Methods with reflectance near-infrared (TCFM-NIR), which involves detecting end-points for active pharmaceutical ingredients (APIs) blending by simultaneously monitoring specific NIR peak intensity of APIs and calculating moving block standard deviation (MBSD). After determining the specific NIR peak range of nicaldipine hydrochloride, conditions for TCFM-NIR were established by monitoring the differential intensity of the second peak (1136 nm) while MBSD was calculated from the NIR peak intensity between 1100 and 1150 nm. In comparison with the validated reference method of UV-VIS spectroscopy, which is particularly destructive, TCFM-NIR was found to be useful in detecting end-points for blending of nicaldipine hydrochloride. TCFM-NIR monitors two important factors for estimation of blend uniformity: API concentration, using specific NIR peak intensity for APIs, and blend homogeneity, using MBSD. Also, the conditions of TCFM-NIR were confirmed to be adequate by using Partial Least Square (PLS). Further, simultaneously monitoring these two blend uniformity factors is more useful in preventing estimation errors for nondestructive monitoring of blend homogeneity than monitoring only one factor, as with NIR spectroscopy.     

聚乙烯透气膜专用料的制备

采用聚乙烯共混体系为基础树脂,聚烯烃弹性(体POE)为增韧剂,碳酸钙为增强填料,制得性能符合透气膜要求的共混料,研究了POE和填料用量对共混体系性能的影响。结果表明:当聚乙烯/POE/碳酸钙质量比为某一适当比例时制,得的共混料完全可以满足透气膜专用料的性能要求。     

原位聚合ZDMA与炭黑并用补强POE的研究

研究了原位聚合甲基丙烯酸锌(ZDMA)与炭黑并用以及体系的填充量、ZDMA理论生成量、ZnO/MMA摩尔比对聚烯烃弹性体(POE)硫化胶性能的影响.结果表明,加入炭黑改善了胶料的拉伸永久变形,当ZDMA与炭黑的用量为50～60份时,填料分散好,对胶料的补强效果显著.ZDMA理论用量为30～40份、ZnO/MMA摩尔比为0.75左右时,胶料的综合力学性能最好.     

PP/nano-CaCO_3/POE复合材料性能研究

采用熔融共混法制备了PP/nano-CaCO3/POE复合材料,分别研究了nano-CaCO3和POE的加入量对复合材料力学性能的影响。结果表明:随着nano-CaCO3用量的增加,复合材料的冲击强度和拉伸强度均呈现出先增加后降低的趋势,弯曲模量呈增加趋势;随着POE用量的增加,复合材料的冲击强度先显著增加而后稍有降低,拉伸强度和弯曲模量均呈下降趋势。     

增容剂EAA对PA6／POE共混体系的相态及性能的影响

采用乙烯－丙烯酸共聚物（EAA）作为尼龙6／乙烯－1－辛烯共聚物弹性体（POE）共混体系的增容剂,详细研究了增容剂用量与共混体系的相态、力学性能和流变性能的关系。结果表明相容剂的加入使共混体系的分散性大大改善,分散相POE粒子明显细化,粒子较均匀地分散在PA6连续相中;相容剂的加入使体系韧性明显提高,拉伸强度和弯曲弹性模量下降,加工性能也得到改善,而且当每100份PA6／POE用量为85／15、EAA用量在4月份左右时,其增容作用达到饱和,综合性能达到最优。     

PP/POE共混物性能分析

对聚丙烯(PP)和聚烯烃弹性体(POE)共混来增韧PP的效果进行研究，通过差示扫描量热计分析了共混物熔点、结晶温度及结晶焙的变化，利用广角X射线衍射仪、透射电镜分别分析了共混物PP晶面间距和共混物中POE的粒径大小和分布。得到PP和POE不同配比共混物性能变化规律。结果也表明，POE增韧PP与POE的添加量粒径大小及分布有密切关系。     

甲基丙烯酸锌增强弹性体的相态研究 II.硫化胶料(英文)

利用扫描电子显微镜(SEM)和透视电子显微镜(TEM)研究了甲基丙烯酸锌增强多种弹性体(包括BR,SBR,EPDM,NBR,EPM,POE和HNBR)的微观相态结构。发现在各体系的硫化胶料中均存在两类基本分散结构:纳米分散结构和微米分散结构。其中纳米增强结构是在胶料过氧化物交联过程中由ZDMA原位聚合生成的;而微米结构就是残余的ZDMA颗粒。这两种结构的尺寸及相对含量因不同的复合体系而不同。对于BR和SBR体系,其微米分散结构较其他体系更多,且纳米分散结构的尺寸相对略小。而在EPDM,NBR,EPM,POE,HNBR中,微米分散结构较少,且纳米分散结构的尺寸相对较大。还研究了ZDMA颗粒的原生尺寸对硫化胶料的相态结构的影响,发现在POE体系,较大的ZDMA原生尺寸将造成其硫化胶料中微米分散结构的大量增多;而EPDM,EPM,NBR,HNBR胶料的相态则对ZDMA原生尺寸的变化不敏感。硫化胶料的微观相态的差异必将对其物理机械性能产生直接的影响。     

DCP用量对动态硫化POE/PP热塑性弹性体性能的影响

研究了过氧化二异丙苯(DCP)用量对动态硫化乙烯一辛烯共聚物聚丙烯(POE/PP)体系的物理性能以及PP结晶形态和POE相态结构的影响。结果表明:随DCP用量的增加,POE/PP体系的交联密度增大,而断裂伸长率、永久变形和拉伸强度下降。过量DCP的加人会导致PP降解,使体系的熔体流动速率随DCP用量的增加呈上升趋势。DSC分析表明,随着DCP用量的增加,POE/PP体系结晶度下降。微观分析得出,DCP对POE/PP体系相态结构影响显著,当DCP用量为1份时交联POE以较小的颗粒均匀分布于PP连续相中。     

POE-g-MAS增韧SAN树脂及其相容性

合成了乙烯-辛烯共聚物(POE)和甲基丙烯酸甲酯-丙烯腈-苯乙烯的接枝共聚物(POE-g-MAS).用POE-g-MAS与苯乙烯-丙烯腈共聚物(SAN)树脂共混制备了具有高抗冲击性能的SAN,POE-g-MAS共混物,研究了接枝链极性、接枝率和POE含量对共混物冲击性能的影响,当m(St)/m(MMA)/m(An)为10:70:20,接枝率为45.1%,w(POE)为25%时,共混物的缺口冲击强度达到56.1kJ/m2.用扫描电子显微镜和差示扫描量热仪研究表明,POE-g-MAS与SAN树脂有良好的相容性.     

Preparation of Poly(ethylene‐octene) Elastomer/Clay/Wood Flour Nanocomposites by a Melting Method

Summary: The new nanocomposites consisting of metallocene poly(ethylene‐octene) (POE), silicate clay and wood flour (WF) were prepared by means of a melt blending method. In addition, maleic anhydride grafted poly(ethylene‐octene) (POE‐g‐MAH) was studied as an alternative to POE. The samples were characterized by XRD, FT‐IR spectroscopy, DSC, TGA, SEM, and mechanical testing. Based on the consideration of thermal and mechanical properties, it was found that the clay content of 11 wt.‐% was optimal for the preparation of POE‐g‐MAH/clay nanocomposites. The POE‐g‐MAH/clay/WF hybrid could obviously improve the mechanical properties of POE‐g‐MAH/WF hybrid since the former had the smaller WF phase size (being always less than 1.5 µm), the Si? O? C bond and the nanoscale dispersion of silicate layers in the polymer matrix. The biodegradation studies showed that the mass of hybrids reduced by about the content of WF. The new POE‐g‐MAH/clay/WF nanocomposites produced from our laboratory can provide a plateau tensile strength at break when the WF content was up to 50 wt.‐%.

     

Effects of clay contents on the dynamic mechanical and rheological properties of polypropylene/MAH‐g‐POE/clay composites

A series of polypropylene/maleic anhydride grafted polypropylene octane elastomer (MAH‐g‐POE)/clay (PPMC) nanocomposites were prepared with a novel compatilizer MAH‐g‐POE and different contents of octadecyl amine modified montmorillonite, and the effects of clay contents on the dynamic mechanical and rheological properties of these PPMC composites were investigated. With clay content increasing, the characteristic X‐ray diffraction peak changed from one to two with intensity decreasing, indicating the decreasing concentration of the intercalated clay layers. The gradual decrease of crystallization temperature of PPMC composites with the increase of clay loading should be attributed to the preferred intercalation of MAH‐g‐POE molecules into clay interlayer during blending, which is also reflected by scanning electron microscopy observations. By evaluating the activation energy for the glass transition process of MAH‐g‐POE and polypropylene (PP) in the PPMC composites, it is found that clay intercalation could cause the restriction effect on the glass transition of both MAH‐g‐POE and PP, and this restriction effect appears stronger for PP and attained the highest degree at 5 wt % clay loading. The melt elasticity of PP could be improved apparently by the addition of MAH‐g‐POE, and 5 wt % clay loading is enough for further enhancing the elastic proportion of PP. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

甲基丙烯酸锌增强弹性体的相态研究Ⅱ.硫化胶料

利用扫描电子显微镜（SEM）和透视电子显微镜（TEM）研究了甲基丙烯酸锌增强多种弹性体（包括BR，SBR，EPDM，NBR，EPM，POE和HNBR）的微观相态结构。发现在各体系的硫化胶料中均存在两类基本分散结构：纳米分散结构和微米分散结构。其中纳米增强结构是在胶料过氧化物交联过程中由ZDMA原位聚合生成的；而微米结构就是残余的ZDMA颗粒。这两种结构的尺寸及相对含量因不同的复合体系而不同。对于BR和SBR体系，其微米分散结构较其他体系更多，且纳米分散结构的尺寸相对略小。而在EPDM，NBR，EPM，POE，HNBR中，微米分散结构较少，且纳米分散结构的尺寸相对较大。还研究了ZDMA颗粒的原生尺寸对硫化胶料的相态结构的影响，发现在POE体系，较大的ZDMA原生尺寸将造成其硫化胶料中微米分散结构的大量增多；而EPDM，EPM，NBR，HNBR胶料的相态则对ZDMA原生尺寸的变化不敏感。硫化胶料的微观相态的差异必将对其物理机械性能产生直接的影响。     

PP／POE／纳米CaCO3复合材料的制备与性能研究

采用逐级分散共混法，制备了PP/POE／纳米CaCO3复合材料，研究了其力学性能和微观结构。逐级分散法先制备纳米CaCO3母料，然后将PP分多次加入含纳米CaCO3的共混体系中，目的在于改善纳米CaCO3的分散，以提高复合材料的力学性能。研究结果表明：采用逐级分散法制备的PP/POE／纳米CaCO3复合材料的冲击强度为64．2kJ／m^2，比直接共混法高16．9％，比通常的母料法高9．7％。复合材料的微观结构研究表明：纳米CaCO3粒子基本上都分布在连续相PP中。     

WPP/NWPCB/POE复合材料的制备及其热解特性

以废旧汽车保险杠(WPP)为基体,废弃线路板非金属粉(NWPCB)为填料,通过熔融共混的方法制备了系列WPP/NWPCB复合材料。在此基础上,用乙烯-辛烯共聚物(POE)和马来酸酐接枝聚丙烯(PP-g-MAH)对复合材料进行了协同改性,以增强复合材料的性能。力学性能测试和冲击断面微观形貌分析表明,POE显著提高了WPP/NWPCB复合材料的韧性,当POE用量为15 g·(100 g)^-1时,冲击强度较改性前提高129%;PP-g-MAH能够有效改善复合材料中填料与基体相容性,当添加量为9 g·(100 g)^-1时,复合材料的机械性能达到最佳,冲击强度、弯曲强度和拉伸强度较改性前分别提高7.8%、23.4%和20%。通过热重-红外联用研究了WPP/NWPCB/POE复合材料的热解过程,结果表明,复合材料在热解过程中除产生烷烃、烯烃及CO₂外,还产生了少量的苯酚类芳香族化合物与HBr等有害气体,同时NWPCB填料的添加提高了复合材料中WPP的热稳定性。