共查询到20条相似文献,搜索用时 31 毫秒
1.
2.
3.
4.
In this study, a new approach was used to prepare polymer composites reinforced by both nanoparticles and continuous fibers. Carbon nanofibers were prebound onto glass fiber mats, and then unsaturated polyester composites were prepared by vacuum-assisted resin transfer molding. Mechanical and thermal properties of these composites were measured and compared with those of the composites synthesized by premixing carbon nanofibers with the polymer resin. Flexural strength and modulus of composites improved with the incorporation of nanoparticles. Specifically, the property improvement was higher in the case of the composites prepared by the new prebound method. It was also found that carbon nanofibers increased the glass transition temperature and reduced the thermal expansion coefficient of unsaturated polyester composites. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers 相似文献
5.
6.
In this work a comparative study on the impact and tensile properties of polyester/sisal fiber reinforced composites was undertaken. The polyester matrix was used bare and modified with: (1) a silane coupling agent; (2) a flame retardant system; and (3) a blend of the silane agent and the flame retardant system. The experimental results show that the flame retardant acts as a particulate reinforcement to the polyester matrix and the silane coupling agent acts as a plasticizer. The simultaneous addition of these two compounds to the polyester resin tended to decrease the performance of the composites. The results obtained show that strength or toughness could be tailored, and although none of the composites manufactured with the modified polyester matrices showed a significant improvement on the fiber–matrix interface strength, a better compromise between impact and tensile properties was obtained with the silane modified matrix. The critical fiber volume fraction was also evaluated and shown to be less than 10% for the sisal–polyester composite investigated here. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1209–1217, 2004 相似文献
7.
Synthesis and photocrosslinking of glass fiber-reinforced composites, based on epoxy acrylate-modified unsaturated polyester, have been investigated. The efficiency of the photocrosslinking process for glass fiber laminates of the polyesters that contain different comonomers has been evaluated by measuring mechanical properties. The data show (i) that 2 mm thick laminates, containing 30–40% glass fiber mats, are cured with UV irradiation for 15 sec at room temperature in air; (ii) that multifunctional acrylate or acrylether monomers added to the polyester resin improve the tensile and flexural properties of the photocured product to a greater extent than do added allylic monomers, due to the different photocrosslinking mechanisms; (iii) that the physical properties of the photocrosslinked laminates are well correlated with the molecular weight of the polyester, the amount of multifunctional monomer added, and the glass fiber content. © 1994 John Wiley & Sons, Inc. 相似文献
8.
硅烷偶联剂改性玻璃微珠用于不饱和聚酯树脂 总被引:5,自引:1,他引:4
采用乙烯基、甲基丙烯酰氧基和环氧基3类硅烷偶联剂对中空和多孔两种玻璃微珠进行了改性,将其用于不饱和聚酯树脂复合材料。利用红外光谱(FTIR)、核磁共振谱仪(NMR)和扫描电镜(SEM)技术,结合力学性能测试对其改性机理进行了分析。结果表明,硅烷偶联剂不改变微珠和不饱和聚酯树脂基体的本体结构。硅烷偶联剂非极性端含有C==C双键,使玻璃微珠具有较大的表面张力,且与不饱和树脂相似的双键使其易于结合;此外,非极性端的链长较长,使其与树脂形成的过渡层具有良好的空间柔软性。对于相同非极性端的硅烷偶联剂,极性端含有大基团的偶联剂与玻璃微珠的结合效果较弱。微珠的均匀外形有益于它与树脂的结合。 相似文献
9.
PET interleaving veils for improved fracture toughness of glass fibre/low‐styrene‐emission unsaturated polyester resin composites
下载免费PDF全文
![点击此处可从《应用聚合物科学杂志》网站下载免费的PDF全文](/ch/ext_images/free.gif)
The use of interleaved polyethylene terephthalate (PET) veils to increase the interlaminar fracture toughness of glass fiber‐reinforced, low‐styrene emission, unsaturated polyester resin composites, was investigated. PET, being chemically similar to the unsaturated polyester resin, was expected to exhibit good wetting and strong interaction with the matrix. Composite laminates were manufactured by hand lay‐up, with the veil content varying up to 7%. The effects of PET veils on the interlaminar shear strength, flexural strength, flexural modulus, glass transition temperature, damping parameters, and Mode‐I interlaminar fracture toughness of the composite were studied. The veils were found to enhance most of these properties, with only minor negative effects on flexural stiffness and Tg. The PET/resin bonding did indeed prove to be strong, but the enhancement of fracture toughness was not as much as expected, because of the weaker glass/resin interface providing an alternative crack propagation path. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 42877. 相似文献
10.
《Journal of Adhesion Science and Technology》2013,27(1):337-355
—Glass fiber/unsaturated polyester composites, prepared by impregnating glass braid with varying thickness coatings (from 200 Å up to 1600 Å thick) of polyester resin, were tested with a DuPont Dynamic Mechanical Analyzer. The effects of the polyester resin thickness and silane treatments on the dynamic mechanical properties of the composites were evaluated. The results are supported by Fourier transform infrared spectroscopy of the composite materials. It is shown that both the concentration and the organo-functional group of the silane coupling agent influence the damping, storage, and loss moduli as well as the glass transition temperature (Tg) of the matrix resin in the closest vicinity to the glass/resin bondline. In the absence of a silane inner layer, a low Tg, 'soft' boundary layer exists due to inhibition of the polyester resin cure by the glass surface. It is noted that a reactive silane, such as γ-methacryloxypropyltrimethoxysilane, promotes the formation of a 'soft' or 'rigid' (high Tg) boundary layer, depending on the concentration of the silane in the treating solution. On the other hand, a non-reactive silane, such as methyltrimethoxysilane, produces a 'rigid' interphase in the entire range of concentrations of the silane solution. An attempt was made to correlate the dynamic mechanical properties of the boundary layer with the fiber/polymer interfacial shear strength. Upon pretreatment of glass fibers with silane coupling agents, the relative magnitude of the loss modulus, E", and the nature of the boundary layer (Tg) seem to be better indicators of efficient stress transfer from the polymer to the glass fiber in the composite system than tan δ. Efficient stress transfer is characterized by a low value of E" and 'soft' boundary layers. The results suggest that the mere presence of glass/polyester chemical bonding is insufficient to ensure effective stress transfer. A strong bond results from the synergistic effect of glass/silane/polymer chemical bonding and a 'soft' boundary layer. 相似文献
11.
采用碱、高锰酸钾及热对剑麻纤维布进行了表面处理,并由真空辅助树脂传递模塑成型(VARTM)工艺制备了剑麻纤维布增强不饱和聚酯树脂复合材料。通过对复合材料的力学性能及吸水性的测试,研究了不同剑麻纤维布表面处理对其不饱和聚酯树脂复合材料性能的影响。结果表明:经过碱处理,复合材料的拉伸、弯曲,冲击强度提高最大,可分别提高26.5%,16.5%和22.6%,吸水率降低了47.5%。对剑麻纤维布进行表面处理可使复合材料的界面性能得到改善,力学性能提高,吸水性降低。 相似文献
12.
综述了2005~2006年国外不饱和聚酯树脂的市场动态、工业发展趋势及技术进展。市场动态包括:原油价格及其对UPR的影响;UPR与不同成型方法的FRP的消费概况;面对全球经济发展战略,UPR树脂工业的兼并重组和发展;2005年中国UPR进出口量;2005年日本不饱和聚酯树脂的消费量;不饱和聚酯复合材料及其应用和销售;汽车用复合材料的不饱和聚酯树脂配方。技术进展包括:固化程度监测仪器;不饱和聚酯树脂的新型改性剂—环氧改性酚醛清漆;低轮廓添加剂;双重引发和促进体系。对生物复合材料工业进展进行了重点介绍。 相似文献
13.
Biocomposites were made with nonwoven hemp mats and unsaturated polyester resin (UPE). The hemp fiber volume fraction was optimized by mechanical testing. The effect of four surface treatments of industrial hemp fibers on mechanical and thermal properties of biocomposites was studied. The treatments done were alkali treatment, silane treatment, UPE (matrix) treatment, and acrylonitrile treatment. Bending strength, modulus of elasticity, tensile strength, tensile modulus, impact strength, storage modulus, loss modulus, and tan δ were evaluated and compared for all composites. The mechanical as well as thermal properties of the biocomposites improved after surface treatments. The properties of the above biocomposites were also compared with E‐glass–mat composite. To achieve balance in properties, a hybrid composite of industrial hemp and glass fibers was made. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1055–1068, 2006 相似文献
14.
Standard and low styrene emission glass fiber‐reinforced unsaturated polyester (FRP) composites were aged by immersion under flexural and tension loads, to evaluate modifications to the mechanical properties as a function of exposure time under stress. The application of a mechanical load does not modify either the quantity of the absorbed water or the diffusion coefficients significantly. For an applied stress of less than 10% of the fiber strength, the influence on aging is small, but for larger applied stresses, the rate of reduction in the mechanical properties is accelerated and, in some cases, premature rupture is observed. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2185–2195, 2002 相似文献
15.
依据热平衡发泡原理,选择NaHCO3、偶氮二甲酰胺(AC)、偶氮二异丁腈和4,4-氧代双苯磺酰肼组成不同热平衡复合发泡剂发泡不饱和聚酯树脂,通过示差扫描量热仪(DSC)、扫描电镜(SEM)和力学性能测试对其发泡机制进行了研究。结果表明:先吸热后放热的热平衡复合发泡剂发泡材料泡孔孔径小且分布均匀。AC与NaHCO3质量比为6∶4组成的热平衡发泡剂制得的发泡不饱和聚酯树脂的表观密度为0.546 g/cm3,压缩强度为13.73 MPa,比压缩强度达到25.15 MPa/(g.cm-3)。 相似文献
16.
The glass fiber reinforced polyester composite materials were prepared with varying contents of boric acid, zinc borate, and magnesium hydroxide as flame retardants to improve the flame retardancy of the composites. Experimental results showed that boric acid exhibited a good flame retardant effect on the polyester composite. When boric acid content is used as 15 wt %, the Limiting Oxygen Index (LOI) value of the composite reached upto 25.3. The increase in boric acid content from 15 to 30 wt %, the LOI values of composite were enhanced from 25.3 to 34.5 by 9.2 units. The LOI values of the composite samples increased with increasing boric acid content. The smoke density results showed that the addition of glass fiber and flame retardants decreased the smoke density of the unreinforced polyester resin. The mechanical properties of the composites have decreased by the addition of flame retardants. The scanning electron micrographs taken from fracture surfaces were examined. The flame retardants, such as boric acid, were well dispersed in the glass fiber reinforced polyester composites and obviously improved the interfacial interaction between glass fibers and polyester composites. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献
17.
Aspen chemithermomechanical pulp fiber‐reinforced unsaturated polyester (UPE) composites were fabricated using premade paper handsheets. The effects of handsheet wet‐pressing pressure, grammage, and subsequent fabrication methods on the composite properties were evaluated. The composites obtained using the optimum process parameters had tensile moduli and tensile strengths comparable with those of traditional glass fiber‐reinforced UPE composites. The pressed composites had very consistent tensile moduli that were well fitted by the Halpin–Tsai and Tsai–Pagano models. The classical Kelly‐Tyson and Bowyer‐Bader models significantly underestimated the composite tensile strengths and the potential reasons for this discrepancy are discussed. POLYM. COMPOS., 2012. © 2011 Society of Plastics Engineers 相似文献
18.
Degradation behavior of ZnO‐glass fiber‐unsaturated polyester composite under exposure to a metal halide lamp is investigated by means of DSC and FTIR. The FTIR results show that the UV photons can increase the carbonyl group on the surface, but ZnO can decrease the carbonyl content and further contribute to the breaking of single bond of carbon to oxygen on the surface. All of the results indicate that for pure unsaturated polyester under the UV exposure in air, the major reaction is photo‐initiated oxidation, whereas for the composites with ZnO, decarbonylation is the major effect. In addition, when the content of ZnO is not higher than 4 wt %, the composites are still transparent, and its effects on the crosslinking process and thermal stability are insignificant. Thus, ZnO can be used as a stabilizer of unsaturated polyester for the glass fiber reinforced polymer industry. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献
19.
20.
Replacement of styrene with acrylated epoxidized soybean oil in an unsaturated polyester resin from propylene glycol,isophthalic acid,and maleic anhydride
下载免费PDF全文
![点击此处可从《应用聚合物科学杂志》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Commercial unsaturated polyester (UPE) resins typically contain a high amount of volatile toxic styrene. A non‐volatile acrylated epoxidized soybean oil (AESO) was found to be an excellent replacement of styrene in a commercially available UPE resin [designated as Styrene‐(PG‐IPA‐MA)] that is derived from propylene glycol (PG), isophthalic acid (IPA), and maleic anhydride (MA) in terms of the mechanical properties of the resulting kenaf fiber‐reinforced composites. The AESO‐(PG‐IPA‐MA) resins had low viscosity and long pot life below 70°C for a typical fiber‐reinforced composite application. AESO and PG‐IPA‐MA were not able to form a strong polymer matrix individually for fiber‐reinforced composites. However, a combination of AESO and PG‐IPA‐MA saw strong synergistic effects between them. The flexural, tensile, and water absorption properties of kenaf fiber‐reinforced composites made from AESO‐(PG‐IPA‐MA) resins were comparable with or even superior to those from the Styrene‐(PG‐IPA‐MA) resin. The AESO/(PG‐IPA‐MA) weight ratio was investigated for maximizing the mechanical properties of the kenaf fiber‐reinforced composites. The curing mechanism of the AESO‐(PG‐IPA‐MA) resins is discussed in detail. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43052. 相似文献