共查询到20条相似文献,搜索用时 15 毫秒
1.
Ümit Alkan Mehmet Kılıç Yaşar Karabul Mustafa Çağlar Orhan İçelli Zeynep Güven Özdemir 《应用聚合物科学杂志》2018,135(31)
In this study, the influences of polypropylene (PP) additive (varying from 20% to 80% wt) and low dose X‐ray irradiation (changing from 25 to 100 Gy) on the mechanical and dielectric properties of low‐density polyethylene (LDPE) were investigated. LDPE/PP film blends were prepared by hot press technique. While the highest Young modulus and tensile strength were observed for the 20%LDPE/80%PP blend at 25 Gy X‐ray irradiation, the same blend had the highest energy at break and percentage strain at break values for 50 Gy X‐ray exposure. These results also indicated a chain scission in the material. The differential scanning calorimetry curves also indicated a chain scission and crosslinking effects in the blends due to X‐ray irradiation. Hence, the higher concentration of PP additive and exposure of low dose X‐ray resulted in a polymer composite with high mechanical performance. On the other hand, the dielectric investigations revealed that the 25 Gy X‐ray irradiated 20%LDPE/80%PP blend may also attract attention for capacitor applications due to its increased static dielectric constant and reduced dielectric loss. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46571. 相似文献
2.
采用丙二酸处理沉淀法BaSO_4填充改性聚丙烯,研究了复合材料的结晶、微观形态和力学性能。广角X射线衍射结果表明,丙二酸处理的BaSO_4有利于聚丙烯中β晶型的形成;扫描电子显微镜观察发现,BaSO_4经处理后在体系中分散性得到改善,冲击断面呈韧性断裂;与未处理的BaSO_4相比,经表面处理的BaSO_4进一步提高了复合材料的冲击韧性。 相似文献
3.
4.
Monitoring of nylon 6,6/carbon fiber composites processing by X‐ray diffraction and thermal analysis
Edson Cocchieri Botelho Clara Leal Nogueira Mirabel Cerqueira Rezende 《应用聚合物科学杂志》2002,86(12):3114-3119
This work reports a study made to obtain carbon fiber/nylon 6,6 prepreg composites by hot‐compression molding. Thermogravimetric analysis (TG) and crystallinity degree determination were carried out to monitor the nylon 6,6 behavior during the different steps of the composite processing. The homogeneity of the carbon fiber/polymer matrix distribution was verified using microscopic analyses and the fiber content was determined by the acid‐digestion method. The results show that the processing parameters employed were adequate, allowing the manufacture of laminates with good texture and an adequate reinforcement/matrix relation (60/40). However, improvements need be done to minimize the pullout effect observed in the tensile specimens. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3114–3119, 2002 相似文献
5.
Zhenhua Wang Yonglai Lu Jun Liu Zhimin Dang Liqun Zhang Weimin Wang 《应用聚合物科学杂志》2011,119(2):1144-1155
In this article, nano‐zinc oxide (ZnO) filled ethylene propylene diene monomer (EPDM) composites are prepared, and the mechanical (static and dynamic) properties and thermal conductivity are investigated respectively, which are further compared with the traditional reinforcing fillers, such as carbon black and nano‐silica. Furthermore, influence of in‐situ modification (mixing operation assisted by silane at high temperature for a certain time) with the silane‐coupling agent Bis‐(3‐thiethoxy silylpropyl)‐tetrasufide (Si69) on the nano‐ZnO filled composites is as well investigated. The results indicate that this novel reinforcing filler nano‐ZnO can not only perform well in reinforcing EPDM but can also improve the thermal conductivity significantly. In‐situ modification with Si69 can enhance the interfacial interaction between nano‐ZnO particles and rubber matrix remarkably, and therefore contribute to the better dispersion of filler. As a result, the mechanical properties and the dynamic heat build‐up of the nano‐ZnO filled composites are improved obviously by in‐situ modification, without influencing the thermal conductivity. In comparison with traditioanl reinforcing fillers, in‐situ modified nano‐ZnO filled composites exhibit the excellent performance in both mechanical (static and dynamic) properties and better thermal conductivity. In general, our work indicates that nano‐ZnO, as the novel thermal conductive reinforcing filler, is suitable to prepare elastomer products serving in dynamic conditions, with the longer expected service life. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 相似文献
6.
M. E. Cagiao F. J. Baltá Calleja F. Spieckermann S. Scholtyssek M. F. Mina M. A. H. Bhuiyan 《应用聚合物科学杂志》2012,124(4):3147-3153
Composites of isotactic polypropylene with various contents of white clay or titanium dioxide TiO2 were prepared by extrusion molding. The extruded composites were melt‐pressed at two different temperatures, and, thereafter, either slowly cooled, or quenched to room temperatures. It is shown that the structure of all the samples, as revealed by wide‐angle X‐ray scattering and small‐angle X‐ray scattering (SAXS), depends on the processing conditions. The lack of SAXS maxima in the composites suggests that the presence of the microadditives hinders the stacking of iPP lamellae. Furthermore, the microindentation hardness H in the slowly cooled composites is influenced by the type and amount of the filler used. However, in the quenched samples H depends only on the amount of the filler used, and not on its type. In case of the quenched iPP/clay composites, the relationship between H and the Young's modulus E is found to be H/E ≈ 0.12, in good agreement with Struik's theoretical predictions of σe ≈ E/30, in consonance with results previously obtained for a series of polyethylene samples with different morphology. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 相似文献
7.
Ji‐Zhao Liang 《应用聚合物科学杂志》2007,104(3):1692-1696
Calcium carbonate (CaCO3)‐filled low‐density polyethylene (LDPE)/linear low‐density polyethylene (LLDPE) composites were fabricated by means of a twin‐screw extruder, and the tensile mechanical properties of the tubing with thickness of 0.5 mm made from these composites were measured at room temperature to identify the effect of the filler concentration on the properties of these composites. The results showed that the tensile elastic modulus increased roughly linearly with increasing weight fraction (?f) of the fillers. The tensile fracture strength (σb) along longitudinal direction was obviously higher than that along transverse direction under the same test conditions, especially at higher filler concentration. The values of σb of the specimens along both the two directions achieved minimum at ?f = 20%. Furthermore, the melt flow rate (MFR) and heat enthalpy (ΔH) of the composite materials were measured. It was found that both the MFR and the ΔH decreased with the addition of ?f. The ΔH for the composite with LDPE/LLDPE ratio of 70/30 was higher than that of the composite with LDPE/LLDPE ratio of 50/50 at the same filler concentration, but contrary to the MFR. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1692–1696, 2007 相似文献
8.
In situ electrical resistance and X‐ray tomography study of copper–tin polymer composites during thermal annealing 下载免费PDF全文
Qing Yang Megan Hoarfrost Beers Min Zheng Richard Lloyd Ting Gao Dilworth Parkinson 《应用聚合物科学杂志》2017,134(43)
In situ electrical conductivity and X‐ray tomography experiments are conducted on a conductive polymer composite containing polyvinylidene fluoride (PVDF) copolymer, copper (Cu), and tin (Sn) during thermal annealing. During annealing, the electrical resistivity drops by an order of magnitude, while X‐ray tomography, electron microscopy, and spectroscopy results show increasingly homogeneous dispersion of Sn in the conductive filler network, accompanied by the formation of Cu–Sn intermetallic around Cu and Sn particles. This study provides detailed insight into the morphological origins of the beneficial effect of thermal annealing on the electrical properties of conductive composites containing low melting metal fillers. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45399. 相似文献
9.
A novel phosphorus‐containing copolyester (PET‐co‐DDP)/barium sulfate (BaSO4) nanocomposite was synthesized by in situ polymerization. The oxygen index values of the resulting nanocomposites decreased with increasing the content of BaSO4 nanoparticles, but their antidripping behaviors were improved obviously through the UL‐94 test. The flammability tests based on the cone calorimetry showed that the introduction of nano‐BaSO4 to the copolyester decreased remarkably the heat release rate and effective heat of combustion. The thermal oxidative decomposition behaviors of PET‐co‐DDP/BaSO4 nanocomposites were studied by a conventional dynamic thermogravimetric analysis in a flowing air atmosphere with a heating rate of 20°C/min. The activation energies determined from Kissinger method, Flynn‐Wall‐Ozawa method, and Friedman method had a same variation trend. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 564–570, 2006 相似文献
10.
Preparation of liquid crystal 4'‐allyloxy‐biphenyl‐4‐ol functionalized MWCNTs and their application on improving mechanical and thermal properties of silicon resin 下载免费PDF全文
Weijian Xiong Xue Gao Dayong Gui Xueqing Cai Guiming Tan Jianhong Liu 《Polymer Engineering and Science》2016,56(10):1118-1124
A liquid crystalline molecule, 4'‐allyloxy‐biphenyl‐4‐ol (AOBPO), was used to functionalize carbon nanotubers (CNTs) via physical means and chemical means, respectively. The physically functionalized CNTs (AOBPO‐CNTs) and chemically functionalized CNTs (AOBPO‐O‐CNTs) were characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), fluorescent spectroscopy, and Raman spectroscopy. The two functionalized CNTs were mixed with silicone resin as fillers to fabricate organosilicone nanocomposites. Scanning electron microscopy (SEM) images indicated that the dispersion of CNTs in silicone resin and compatibility of CNTs with silicone resin were improved effectively after functionalization with liquid crystal via physical or chemical means. The thermal and mechanical properties testing indicated that, the chemically functionalized CNTs got a better effect in improvement of mechanical properties of silicon resin than the physically functionalized CNTs, whereas the physically functionalized CNTs was more applicable to enhance the thermal conductivity of silicon resin. The tensile strength of AOBPO‐O‐CNTs/silicon resin increased by 37.8% over that of neat CNTs/silicon resin when the mass fraction of AOBPO‐O‐CNTs was 1.0%, and the elastic modulus of AOBPO‐O‐CNTs/silicon resin increased by 32.8% over that of CNTs/silicon resin if it came up to 2.0%. The thermal conductivity of the resin filled with AOBPO‐CNTs was improved to be 1.176 W (m?1 K?1) at the mass fraction of 5.0%, which was enhanced more than 73.2% over that of CNTs/silicon resin. POLYM. ENG. SCI., 56:1118–1124, 2016. © 2016 Society of Plastics Engineers 相似文献
11.
Yau Thim Ng Kim Yeow Tshai Wei Kong Sahrim Haji Ahmad Oliver Buddrick Ing Kong 《Polymer International》2017,66(11):1430-1437
Advanced polymer composites containing organic–inorganic fillers are gaining increasing attention due to their multifunctional applications. In this work, poly(styrene‐butadiene‐styrene) (SBS) composites containing magnetite‐functionalized graphene (FG) were prepared by a dissolution ? dispersion ? precipitation solution method. Evidently, through morphology studies, amounts of FG were well distributed in the SBS matrix. Improvements in neat SBS properties with respect to FG loading in terms of thermal stability, creep recovery and mechanical properties are presented. As expected, the addition of FG improved the thermal stability and mechanical properties of the composites. The yield strength and Young's modulus of the SBS increased by 66% and 146% at 5 wt% filler loading which can be attributed to the reinforcing nature of FG. Similarly, an increase in the storage and loss modulus of the composites showed a reinforcement effect of the filler even at low concentration. The results also showed the significant role of FG in improving the creep and recovery performance of the SBS copolymer. Creep deformation decreased with filler loading but increased with temperature. © 2017 Society of Chemical Industry 相似文献
12.
13.
14.
PVC‐clay nanocomposites were prepared by melt blending of the polymer with an organically modified clay, both in the presence and in the absence of di(2‐ethylhexyl) phthalate (DOP). The clay can serve as a plasticizer for PVC in the absence of DOP. The nanocomposites were characterized by using X‐ray diffraction and transmission electron microscopy, and the materials were found to be largely intercalated. Thermal properties were evaluated by using thermogravimetric analysis, and the thermal stability was determined to be variable, depending upon the amounts of clay and DOP that were present. The fraction of polymer that remained at 600°C was significantly reduced in the presence of the clay, a result indicating that the clay had an effect on the course of the degradation of the PVC. The tensile strength of the nanocomposites increased as the fraction of clay increased, and the addition of a small amount of clay increased the elongation, but when additional clay was added, the elongation decreased. 相似文献
15.
Barium titanate/polyvinylidene fluoride (BaTiO3)x (PVDF)100–x composite samples were prepared and characterized using X‐ray diffraction (XRD) and differential scanning calorimetry (DSC) techniques. In this work, the ratio of the constituents of this composite was altered, and the structural and thermal changes were studied. Also, the variation of tetragonality of BaTiO3 (BT) in the composite samples as a function of BT content was studied for the first time. The results show that all the samples are in the α‐phase, and the hindrance to the PVDF crystallization increases with the increase of BaTiO3 (BT) ratio in the composite. Tetragonal distortion of BT nanoparticles in the composite increases with the increase in BT ratio up to 30%, where it gets a saturation value. Also, it seems that stretching the samples enhances the BT tetragonality. Both melting and crystallization behaviors of the composite samples show double‐melting endotherms (reorganization) and crystallization exotherms. The inclusion of BT in the composite samples results in a decrease in the melting temperature of the samples. POLYM. ENG. SCI., 52:1945–1950, 2012. © 2012 Society of Plastics Engineers 相似文献
16.
Short ramie fiber (RF) was used to reinforce the polypropylene (PP). The composites were prepared in a twin‐screw extruder followed by injection molding. The experimental results showed that both the strength and the modulus of the composites increase considerably with increasing RF content. The tensile strength and flexural strength are as high as 67 and 80 MPa by the incorporation of ramie up to 30 wt %. To the best of our knowledge, this is one of the best results for short natural fiber‐reinforced PP composites. However, the preparation method in this study is more simple and economic. This short RF‐reinforced PP composites extend the application field for short‐nature fiber‐reinforced PP composites. Morphological analysis revealed that it is the high aspect ratio of the fiber and good interfacial compatibility that result in the high performance of the composites. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 相似文献
17.
Diène Ndiaye Laurent M. Matuana Sandrine Morlat‐Therias Loïc Vidal Adams Tidjani Jean‐Luc Gardette 《应用聚合物科学杂志》2011,119(6):3321-3328
In this research, polypropylene/wood‐flour composites (WPCs) were blended with different contents of wood and/or maleated polypropylene (MAPP) and clay. We found that the addition of MAPP or clay in the formulation greatly improved the dispersion of the wood fibers in the composite; this suggested that MAPP or clay may have played the role of an adhesion promoter in the WPCs. The results obtained with clay indicate that it also acted as a flame retardant. The thermal tests carried out with the produced samples showed an increased crystallization temperature (Tc), crystallinity, and melting temperature (Tm) with wood loading. The increase of the two former parameters was explained by the incorporation of wood flour, which played the role of nucleating agent and induced the crystallization of the matrix polymer. On the other hand, the Tm increase was ascribed to the insulating properties of wood, which hindered the movement of heat conduction. The effects of UV irradiation on Tm and Tc were also examined. Tc increased with UV exposure time; this implied that UV degradation generated short chains with low molecular weight that could move easily in the bulk of the sample and, thus, catalyze early crystallization. The flexural strength and modulus increased with increasing wood‐flour content. In contrast, the impact strength and tensile strength and strain decreased with increasing wood‐flour content. All of these changes were related to the level of dispersion of the wood flour in the polymeric matrix. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 相似文献
18.
Preparation and characterization of core‐shell polystyrene/polyaniline/Pd composites and their catalytic properties for the reduction of 4‐nitrophenol 下载免费PDF全文
Herein, polystyrene/polyaniline/Pd (PS/PANI/Pd) core‐shell composite catalysts were prepared by a facile swelling‐diffusion‐interfacial polymerization method. PS microparticles were firstly prepared by dispersion polymerization and were swollen by aniline monomer without any surface modification. H2PdCl4 acid was used as palladium precursor. The was adsorbed on the surface of aniline‐swollen PS microparticles because of the electrostatic attraction between and anilinium positive ions protonated by H+, which was diffused from the aniline‐swollen PS microparticles. Then HCl solution was added to control the diffusion rate of anilinium positive ions and ammonium persulfate (APS) was used to polymerize the anilinium ions to get PANI shell. Due to the redox activity between PANI and Pd ions, Pd nanoparticles can be in situ formed on the surfaces of PS. Therefore, the core‐shell PS/PANI/Pd composite catalysts were obtained. The morphology and structure of the obtained composites was characterized by TEM, FT‐IR and EDX. Results showed that the products presented excellent catalytic properties for the reduction of 4‐nitrophenol (4‐NP) to 4‐aminophenol (4‐AP) in the presence of NaBH4 by virtue of the interaction between Pd nanoparticles and conducive PANI shell. The catalytic reaction obeyed the pseudo‐first‐order reaction equations and the reaction rate constants were also calculated in this article. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44812. 相似文献
19.
Yanhong Feng Hanzhi Shen Jinping Qu Bin Liu Hezhi He Liyan Han 《Polymer Engineering and Science》2011,51(3):474-481
We report the preparation of polybutylene succinate (PBS)/sisal‐fiber (SF) composites. The effects of mixing temperature and of steam‐explosion pretreatment of SFs on the mechanical properties of the composites were investigated, and the mechanism of action was studied by infrared spectroscopy, scanning electron microscopy, and x‐ray photoelectron spectroscopy. The results indicate that as the mixing temperature increases, PBS flows better and can graft onto steam‐exploded sisal fiber (SESF), the interfacial bond property between SESF and PBS improves, and the mechanical properties of the composites improve. The mechanical properties of the composites are maximal for a mixing temperature of 200°C. The results also demonstrate that the cellulose content and the specific fiber surface area can be increased by steam‐explosion pretreatment, so that the mechanical properties of the composites can be improved. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers 相似文献
20.
Emre Batürk Seyfullah Madakba Betül Karadoan Memet Vezir Kahraman 《Polymer Composites》2016,37(11):3275-3279
In this report, it was aimed to the improve thermal stability of polyethylene terephthalate (PET) by adding huntite/hydromagnesite minerale. PET/huntite/hydromagnesite composites were prepared by adding various proportions of huntite/hydromagnesite to PET. The chemical structures of the composites were characterized by Fourier transform infrared spectroscopy (FTIR) and X‐ray diffraction (XRD) analysis. Thermal properties of the composites were determined by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Glass‐transition temperatures and char yields increased with the increase of the huntite/hydromagnesite content in the composites. The surface morphologies of the composites were investigated by a scanning electron microscopy. The obtained results proved that the composite system is more thermally stable than the pure PET itself. POLYM. COMPOS., 37:3275–3279, 2016. © 2015 Society of Plastics Engineers 相似文献