PP—g—AA增容尼龙1010／聚丙烯三元共混体系性能研究

用反应挤出方法制备了聚丙烯接枝丙烯酸。用电子显微镜观测了不同ＰＰ－ｇ－ＡＡ含量的ＰＡ１０１０／ＰＰ／ＰＰ－ｇ－ＡＡ三元共混物的形态。与没有加ＰＰ－ｇ－ＡＡ的共混体系相比，增容共混中分散相尺寸明显减小，两相间镶嵌更深。ＰＰ－ｇ－ＡＡ作为第三组分加对其物理力学性能有一定程度的改善。     

Effect of graphene oxide on the properties of compatibilized polypropylene/ethylene-propylene-rubber blend

In this work, the effect of graphene oxide (GO) and its derivatives on the mechanical, thermal and morphological properties of nanocomposites based on polypropylene/ethylene-propylene rubber (PP/EPR) were investigated. In order to achieve a better dispersion of the nanofiller and to enhance its interaction with the polymer matrix, amine and alcohol grafted polypropylene were used as compatibilizers. These compatibilizers were synthesized by the reaction of polypropylene-grafted anhydride maleic (PP-g-MAH) with 1,12-dodecanediamine and 1,12-dodecanediol, respectively in the presence of dicumyl peroxide (DCP) by melt mixing. The nanocomposites were prepared via melt blending masterbatch process using Brabender mixer. The addition of functionalized GO and compatibilizers improved the tensile strength and Young’s modulus of PP/EPR nanocomposite. While the elongation and Izod impact strength were adversely affected. Furthermore, the TGA analysis showed that the incorporation of GO and compatibilizers improve significantly the thermal stability. SEM micrographs of the fractured surfaces of the nanocomposites revealed a good dispersion of functionalized GO in the polymer matrix.     

Compatibilizing effect of maleated polypropylene on the mechanical properties and morphology of injection molded polyamide 6/polypropylene/organoclay nanocomposites

Polyamide 6/polypropylene (PA6/PP=70/30 parts) blends containing 4 phr (parts per hundred resin) of organophilic modified montmorillonite (organoclay) were prepared using twin screw extruder followed by injection molding. Maleated polypropylene (MAH-g-PP) was used to compatibilize the blend system. The mechanical properties of PA6/PP nanocomposites were studied through tensile and flexural tests. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to assess the fracture surface morphology and the dispersion of the organoclay, respectively. X-ray diffraction (XRD) was used to characterize the formation of nanocomposites. The thermal properties were characterized by using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The dynamic mechanical properties of PA6/PP nanocomposites were analyzed by using dynamic mechanical thermal analyzer (DMTA). The strength and stiffness of PA6/PP nanocomposites were improved significantly in the presence of MAH-g-PP. This has been attributed to the synergistic effect of organoclay and MAH-g-PP. The MAH-g-PP compatibilized PA6/PP nanocomposites showed a homogeneous morphology supporting the compatibility improvement between PA6, PP and organoclay. TEM and XRD results revealed the formation of nanocomposites as the organoclay was intercalated and exfoliated. A possible chemical interaction between PA6, PP, organophilic modified montmorillonite and MAH-g-PP was proposed based on the experimental work.     

Preparation and properties of polypropylene/org-attapulgite nanocomposites

Polypropylene (PP)/org-attapulgite (ATP) nanocomposites were prepared by melt blending in a mixer apparatus. Org-attapulgite was attained by silane coupling agent modification first and then graft-polymerization with butyl acrylate. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to assess the clay morphology and the dispersion of the org-attapulgite, respectively. The changes of crystalline structure for PP nanocomposites were characterized by X-ray diffraction (XRD). The mechanical properties of PP/attapulgite nanocomposites were studied through tensile and impact tests. The thermal and dynamic mechanical properties were characterized by differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). The strength and stiffness of PP/org-ATP nanocomposites were both improved significantly in the presence of organic attapulgite. In addition, the incorporation of org-ATP also gave rise to an increase of the storage modulus and the changes of the glass transition temperature for PP composites. TEM and XRD results revealed the addition of attapulgite did not change the crystal structure of PP, however org-attapulgite acted as nucleating agents for the crystallization of PP.     

Effect of oxygen functional groups of reduced graphene oxide on the mechanical and thermal properties of polypropylene nanocomposites

Reduced graphene oxide (rGO) with various surface structures was prepared by reducing graphene oxide (GO) with hydrazine hydrate (N₂H₄), sodium borohydride (NaBH₄) and l ‐ascorbic acid, respectively. The resulting rGO were used to fabricate rGO/polypropylene (PP) nanocomposites by a melt‐blending method. The surface structure of rGO as well as multifunctional properties of rGO/PP nanocomposites were thoroughly investigated. It was shown that rGO with highest C/O ratio could be obtained by reducing GO with N₂H₄. The crystallization behaviors, tensile strength, thermal conductivity and thermal stability of rGO/PP nanocomposites were significantly improved with the increase of C/O ratio of rGO. For example, with only 1 phr (parts per hundred PP) rGO reduced by N₂H₄, the degree of crystallinity, tensile strength, maximum heat decomposition temperature and thermal conductivity of PP nanocomposite were increased by 6.2%, 20.5%, 48.0 °C and 54.5%, respectively, compared with those of pure PP. Moreover, the thermal degradation kinetics indicated that the decomposition activation energy of rGO/PP nanocomposites could be enhanced by adding rGO with higher C/O ratio. © 2018 Society of Chemical Industry     

Effects of surface functionalized partially reduced graphene oxide and different compatibilizers on the properties and structure of PP/EPR nanocomposites

In this study polypropylene/ethylene-propylene rubber (PP/EPR) and different amounts of partially reduced graphene oxide (prGO) and its derivatives were investigated. The nanocomposites were also compatibilized with EPR containing diethyl maleate (DEM), glycidyl methacrylate (GMA) and maleic anhydride (MAH) functionality as a means of controlling their ultimate mechanical behaviour and their structural morphology. Mechanical tests show that the addition of pristine prGO to PP/EPR blend promotes tensile strength and Young’s modulus, while reducing elongation at break and impact strength. A significant improvement of these properties was achieved by the presence of functionalized prGO and EPR-g-DEM. TGA analysis showed that the nanocomposites exhibit a higher thermal stability than that of the matrix alone. XRD analysis revealed that the polymer chains have been successfully intercalated into prGO layers. SEM has been used to verify the dispersion of the prGO particles in the matrix and to reveal the developed morphology of PP/EPR, in the presence of compatibilizers and functionalized prGO.     

PP／PET合金纤维的形态和热性能研究

用聚丙烯接枝丙烯酸(PP-g-AA)作增容剂,制备了PP／PET共混合金纤维。对合金纤维碱处理后的表面以及拉伸断裂后的断面形态进行SEM观察,结果表明分散相PET原位形成微纤。DSC研究结果显示,PET在复合体系中起到了异相成核的作用,使PP的结晶速率加快,同时发现加有增容剂PP-g-AA的结晶性能稍有下降,说明增容剂起到了良好的增容效果。     

Enhanced through-plane thermal conductive properties of Ag/rGO nanocomposite

High thermal conductivity of nanocomposite-based polymer matrix is one of the most important keys in developing many heat exchanger instruments. Here, we report a novel nanocomposite system based on silver-coated reduced graphene oxide (Ag/rGO) in silane cross-linked low-density polyethylene (XLPE) matrix with unprecedented through-plane thermal conductivity. Compared to the virgin rGO, Ag/rGO nanocomposite showed 67% higher thermal conductivity due to the Ag nanoparticles (NPs) decoration. The Ag NPs within the nanocomposites are believed to act as a thermal conductor among rGO nanosheets and eventually enhance the heat conduction in 3D manner.     

Structure and properties of polypropylene/clay nanocomposites compatibilized by solid‐phase grafted polypropylene

Polypropylene/organic‐montmorillonite (PP/OMMT) nanocomposites were prepared via a solid‐phase PP graft (TMPP) with a higher grafting level as the compatibilizer. The effects of the compatibilizer on the structure and properties of PP/OMMT nanocomposites were investigated. The structure of the nanocomposites were characterized by X‐ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The results showed that when the weight ratio of TMPP and OMMT is greater than 1:1, the OMMT can be dispersed in PP matrix uniformly at the nanoscale. The mechanical properties of the nanocomposites reached a maximum when the weight ratio of TMPP and OMMT is 1:1, although more uniform dispersion was achieved at a higher content of TMPP. The mechanical properties of the nanocomposites decrease with the content of TMPP. The crystallization behavior, dynamic rheological property, and thermal stability of the nanocomposites were investigated by differential scanning calorimetry (DSC), dynamic rheological analysis, and thermal gravimetric analysis (TGA), respectively. Due to the synergistic effects of TMPP and OMMT on the crystallization of PP, the crystallization peak temperature of the nanocomposites increased remarkably compared with that of the neat PP. TMPP shows β‐phase nucleating ability and OMMT promotes the development of β‐phase crystallite. The nanocomposites show restricted melt flow and enhanced temperature sensitivity compared with the neat PP. The thermal stability of the nanocomposites is obviously improved compared with that of the neat PP. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers.     

Synergism on tensile properties of injection molded polybutene-1 /polypropylene blends

Blends of polybutene- 1 (PB-1) and polypropylene (PP) have been injection and compression molded. A synergism appears in the ultimate elongation and the tensile strength for the injection moldings. The maximum point of the synergism at the composition of 25 wt% PB-1 shifts to 50 wt% PB-1 after annealing at 145° C for 1 h. A linear relation and negative deviation from the additivity rule for these two properties are observed for the compression moldings with quick cooling and slow cooling, respectively. Thermal analysis, polarized optical microscopy, and scanning electron microscopy (SEM) are used to study the occurrence of the synergism. The mutual interference between the two components on the crystal formation and the plasticization effect of PB- 1 on PP result in the synergism. An increased phase separation probably occurs during the compression molding with slow cooling. So, the blends compression-molded with slow cooling having a higher amount of PP have brittle breaks, similar to pure PP.     

Preparation and Properties of PB-1/PP Blends

Crystallization behavior, dynamic mechanical properties, mechanical properties and rheological properties of isotactic polybutene-1/polypropylene (PB-1/PP) blends prepared by melt-blending the two components through Brabender extruder were mainly studied via POM, DSC, DMA, capillary rheometer and so on, respectively. The results indicated that after adding PP in PB-1: size of the spherical crystal and degree of crystallization of PB-1 in the blends decreased, its melt temperature and crystallization temperature unchanged; tensile property of the blends was decreased, but impact and flexural properties were improved; change of the melt viscosity of the blends with the shear rate was more sensitive than pure PB-1.     

Synthesis of polypropylene‐grafted graphene and its compatibilization effect on polypropylene/polystyrene blends

Polypropylene‐graft‐reduced graphene oxide (PP‐g‐rGO) was synthesized and used as a novel compatibilizer for PP/polystyrene (PP/PS) immiscible polymer blends. SEM observation revealed an obvious reduction of the average diameter for the dispersed PS phase with the addition of PP‐g‐rGO into a PP/PS (70/30, w/w) blend. The compatibilization effect of PP‐g‐rGO will subsequently lead to the enhancement of the tensile strength and elongation at break of the PP/PS blends. The compatibilizing mechanism should be ascribed to the fact that PP‐g‐rGO can not only adsorb PS chains on their basal planes through π‐π stacking but also exhibit intermolecular interactions with PP through the grafted PP chains. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40455.     

PP/EVOH共混物结构与性能研究

采用丙烯酸接枝聚丙烯（PP-g-AA）、衣康酸接枝聚丙烯 (PP-g-ITA)、马来酸酐接枝聚丙烯 (PP-g-MAH)3种相容剂增容聚丙烯（PP）/乙烯-乙烯醇共聚物(EVOH)共混体系,研究了共混体系的相容性、热性能、力学性能和阻隔性能。红外光谱分析表明,相容性的改善源于相容剂与EVOH之间形成的酯键和氢键。扫描电镜显示,PP-g-AA、PP-g-ITA、PP-g-MAH的增容作用依次增强,共混体系中相容剂增容作用越强,分散相尺寸越小,界面结合越牢固。差示扫描量热分析发现,PP/EVOH增容共混体系中EVOH组分的结晶温度低于不含相容剂的共混体系EVOH组分的结晶温度,PP组分的结晶温度变化则相反。增容共混体系与不含相容剂的共混体系相比,拉伸强度提高了10 MPa,吸油率降幅达0.8 %。     

Effect of Compatibilizer Type on Properties of 70:30 Polyamide 6/Polypropylene/MMT Nanocomposites

PA6/PP nanocomposites with either polyethylene octene elastomer grafted maleic anhydride (POEgMAH) or PP grafted maleic anhydride (PPgMAH) as compatibilizer were prepared using co-rotating twin-screw extruder followed by injection molding. The mechanical and microstructural properties of the composites were investigated by means of tensile, flexural, and impact testing and by scanning electron microscopy (SEM). X-ray diffraction (XRD) was used to characterize the formation of nanocomposites. The result indicated that the miscibility of PA6/PP nanocomposites was improved with the addition of POEgMAH and PPgMAH. The impact strength of PA6/PP nanocomposite with POEgMAH increased about 5 times higher than uncompatibilized composite. Increment in tensile properties was observed when PPgMAH was used as compatibilizer. XRD results revealed that PA6/PP nanocomposites were successfully formed. Uniform dispersion of PP in matrix were observed through SEM, which showed the improvement of the compatibility between polymers.     

Surface‐activated nanosilica treated with silane coupling agents/polypropylene composites: Mechanical,morphological, and thermal studies

This work reports the mechanical, morphological, and thermal properties of the polypropylene (PP) nanocomposites containing nanosilica (nano‐SiO₂) which were treated by different functional group silane coupling agents. Four types of silane coupling agents namely aminopropyltriethoxy silane (APTES), glycidyloxypropyltrimethoxy silane (GPTMS), trimethoxysilylpropyl methacrylate (TMPM), and dichlorodimethyl silane (DCMS) were used to modify the surface‐activated nanosilica. To enhance the effectiveness of the coupling, nanosilica was chemically activated and analyzed through FTIR and X‐ray photo electron spectroscopy (XPS). The highest tensile strength was recorded by the activated nanocomposites treated with APTES followed by nanocomposite treated with GPTMS, TMPM, and DCMS, respectively. The addition of silane coupling agents into nano‐SiO₂/PP system further improved the tensile modulus of the PP nanocomposites. From the transmission electron microscopy (TEM) analysis, activated nanosilica treated with APTES showed better nanosilica dispersion in the PP matrix and lesser agglomeration occurred when compared with the other silane coupling agents which were used in this study. Surface activation process does not effectively increase the degree of crystallinity and thermal stability on the PP nanocomposites. However, with the assistance of the surface treatment, it was found that the thermal behavior of the PP nanocomposites had been enhanced. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers     

PP/PET共混体系及其合金纤维的研究

用增容剂PP-g-AA增容PP/PET共混体系。研究了增容剂含量、共混物组成、共混时间、共混温度以及螺杆转速对PP/PET相形态的影响。结果表明:增容剂的加入大大改善了PP/PET两相间的相容性,并且增容剂的添加量有一最佳值,为PET质量的50%。随着PET含量的增加,分散相的尺寸有所增加。共混温度和共混时间均有一最佳值。随着螺杆转速的提高,分散相的尺寸减小,分布趋于均一,相容性也得到改善。另外,还制备了PP/PET合金纤维,对其表面处理后以及断面SEM观察均表明分散相PET原位成纤,这些微纤提高了合金纤维的力学性能。测试了合金纤维的力学性能,发现组分比为90/10/5时,合金纤维具有最好的力学性能。     

丙烯酸和苯乙烯改性PP/PS结晶与熔融行为

制备了苯乙烯（St）、St与丙烯酸（AA）混合物、丙烯酸接枝聚丙烯（PP-g-AA）改性聚丙烯／聚苯乙烯（PP／PS）共混物以及AA，St改性PP（原位形成PP／PS共混物）。用差示扫描量热仪（DSC）研究了3种改性方法对共混物中PP结晶与熔融行为的影响。结果表明，PS对PP的结晶与熔融温度影响不大，PP-g-AA则提高共混物中PP的结晶温度。St以及St与AA混合单体对PP／PS中PP结晶温度影响不大，但AA改性提高PP／PS中PP结晶温度。St加入PP导致PP结晶温度下降，St与AA混合单体原位聚合则提高PP的结晶温度。改性对共混物中PP的熔融温度影响不大，但是熔融峰形与结晶温度高低有关。红外光谱证实St与AA混合单体改性PP中有PP-g-AA形成，但改性共混物中没有PP-g-AA形成。     

PP-g-AA对PP/云母增容作用的研究

研究了聚丙烯(PP)与云母共混时,添加第3组分PP—g—AA对PP/云母共混体系的影响。用扫描电镜观察共混体系中云母的分布状况。研究结果表明,加入第3组分增加了共混体系的相容性,使拉伸强度和抗冲击强度均明显提高。     

硅烷偶联剂KH-550在聚丙烯/二溴新戊二醇磷酸酯三聚氰胺盐复合阻燃材料中的增容作用

考察了硅烷偶联剂（KH-550）在聚丙烯（PP）/二溴新戊二醇磷酸酯三聚氰胺盐（BPMS）（90/10,质量比,下同）共混物中的增容作用。力学性能和阻燃性能测试结果表明,加入0.3 %（质量分数,下同） 的KH-550后,材料的拉伸强度达到34.34 MPa,冲击强度达到4.48 kJ/m2,分别比PP/BPMS共混物的提高了7.9 %和40.4 %,同时保持材料遇火不滴落,可自熄。红外光谱和流变行为研究证实,BPMS与KH-550之间发生化学作用,KH-550接枝到BPMS上,由于KH-550包裹在BPMS的表面,减弱了BPMS对PP的异核结晶作用,因此在偏光显微镜照片中显示PP球晶增大,X射线衍射分析表明,BPMS对 PP(040)面优势结晶作用减弱,扫描电子显微镜照片进一步说明PP与BPMS的界面黏结强度增加。     

Dynamic viscoelastic behavior of polypropylene/polybutene-1 blends and its correlation with morphology

In this study the rheology, morphology, and interfacial interaction of polypropylene (PP)/polybutene-1 (PB-1) blends in different percentages of PB-1 are investigated. The morphology of cryo-fractured surfaces of samples was studied by scanning electron microscopy (SEM). The SEM images showed a droplet-matrix structure in all range of compositions and the size of dispersed phase increased proportionally with PB-1 content. The miscibility of blends at various compositions is evaluated by viscoelastic parameters determined by dynamic oscillation rheometry in the linear viscoelastic region. A distinct Newtonian plateau at low frequencies is observed and the variations of complex viscosity (η*) against angular frequency (ω) for all blends are in agreement with Cross model. The complex viscosity of samples at various percentages of PB-1 showed the log-additivity mixing rule behavior in low frequencies and positive-negative deviation behavior (PNDB) at high shear rates. The phenomena such as decrease in the sensitivity of storage modulus to shear rate in the terminal region, the deviation of Cole–Cole plots from the semi-circular shape, and the tail in relaxation spectrums at high relaxation times are the evidences of two phase heterogenous morphology. The effect of time–temperature on the phase behavior is studied and the interfacial tension between matrix and dispersed phase was evaluated by using emulsion theoretical models. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012