The role of additives in the manufacture of sheets of unsaturated polyester and postconsumer unsaturated polyester/glass fiber composites: Mechanical and dynamic mechanical properties

The storage of postconsumer glass fiber reinforced unsaturated polyester composite impacts negatively on the environment because of the long lifetime and the volume/amount ratio of residuals, which are important aspects to be considered. Two types of additives were employed as an attempt to improve the mechanical properties of sheets manufactured with ground postconsumer glass fiber reinforced orthophthalic unsaturated polyester resin composite and virgin orthophthalic unsaturated polyester resin, a silane‐coupling agent and an organic dispersant. Flexural and impact tests, and dynamic mechanical analyses, demonstrated that the coupling agent increased the mechanical properties, while the dispersant decreased these properties, compared to material without either additive. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 1834–1839, 2004     

不饱和聚酯型人造大理石的力学性能

简述了不饱和聚酯(UPR)型人造大理石的制备工艺。研究了质量比为4∶1的Al(OH)3/Ca(OH)2复合填料用量对不饱和聚酯型人造大理石力学性能的影响,对制得的人造大理石的耐腐蚀性进行了测试,采用光学显微镜观察了试样腐蚀前后的表面形貌。结果表明,在复合填料与UPR质量比为1.86∶1时,弯曲强度、压缩强度达到最大,分别为55.88 MPa和96.04 MPa。甲苯对人造石的腐蚀作用最大,氢氧化钠次之,硫酸腐蚀作用较小,腐蚀介质主要对不饱和树脂聚合物产生腐蚀,从而导致人造石力学性能降低。     

豆油制备不饱和聚酯树脂性能研究

以可再生资源豆油、丙三醇为原料醇解制备了单甘酯,将其作为二元醇,部分取代丙二醇与酸酐反应制得不饱和聚酯树脂(UP)。采用DSC,DMA以及力学性能测试等手段研究了单甘酯含量对豆油不饱和聚酯树脂性能的影响。结果表明,随着单甘酯含量的增加,豆油不饱和聚酯树脂的固化放热峰值降低、固化收缩率减小;存储模量和玻璃化转变温度都有一定程度降低,弯曲强度和拉伸强度也逐渐下降;冲击强度和拉伸断裂伸长率增高(单甘酯质量分数为40%时可分别达到102.074 kJ/m2和27.69%)。该方法制备的UP树脂成本低廉,柔韧性好,可满足一般的使用要求。     

Morphology development and mechanical properties of unsaturated polyester resin containing nanodiamonds

Unsaturated polyester/styrene (UP ) resin was filled with nanodiamonds (NDs ) containing carboxyl and methacrylate functionalities using mechanical mixing. Field emission SEM exhibited a uniform dispersion of tightly bound aggregates of nanosized spherical NDs with good interfacial interaction. Rheological measurements exhibited a step increment in the shear viscosity of a UP /ND suspension at 0.6 wt% ND resembling a percolation state at this loading. Shear viscosity data supported by dynamic mechanical analysis results suggested the development of effective ND particles in which ND aggregates were covered by only polyester macromolecules. Accordingly, the morphology of UP /ND composites approached a quasi‐percolation state at 0.6 wt% in which effective ND particles were connected thoroughly, instead of direct ND ?ND contact, forming a co‐continuous polyester phase covering the ND particles. Based on such morphology, DSC and Fourier transform infrared analysis suggested the development of heterogeneous microgels in cured UP resin containing NDs which in turn governed the overall mechanical properties of the composites. © 2017 Society of Chemical Industry     

Physical properties of unsaturated polyester resin from glycolyzed pet fabrics

Physical properties of unsaturated polyester resins (UPE resins) prepared from glycolyzed poly (ethylene terephthalate) (PET) and PET/cotton blended fabrics were investigated. Initially, PET and PET/cotton blended fabrics were chemically recycled by glycolysis. The depolymerizations were carried out in propylene glycol with the presence of zinc acetate as a catalyst. The reaction time was varied at 4, 6, and 8 h. The glycolyzed products were then esterified using maleic anhydride to obtain UPE resins. The prepared resins were cured using styrene monomer, methyl ethyl ketone peroxide, and cobalt octoate as a crosslinking agent, an initiator and an accelerator, respectively. The cured resin products were tested for their mechanical properties and thermal stability. The results indicated that, among the fabric based resins, one prepared from the 8‐h glycolyzed product possessed the highest mechanical properties those are tensile strength, tensile modulus, flexural strength, impact strength, and hardness. The highest thermal stability was also found in the cured resin prepared from the 8‐h glycolyzed product. The mechanical properties of fabric based resins were slightly lower than those of the bottle based resin. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2536–2541, 2007     

Effect of fiber surface treatment on the properties of biocomposites from nonwoven industrial hemp fiber mats and unsaturated polyester resin

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     

Modification of unsaturated polyester resin with bismaleimide

The modification of a commercially available unsaturated polyester resin with 4,4′‐bismaleimidodiphenylmethane is presented. The properties of the modified resins were compared with those of the nonmodified resin, and the resins were characterized in the noncured state and after curing. The results indicate that the addition of bismaleimide to unsaturated polyester resin not only improves its properties but also accelerates the curing reactions. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2003–2007, 2001     

2009-2010年国外不饱和聚酯树脂工业进展

介绍了2009-2010年国外不饱和聚酯树脂(UPR)企业的运营情况,UPR主要原料(苯乙烯、苯酐、顺酐、丙二醇)的供需状况。综述了UPR领域的研究及应用进展,包括生物基UPR复合材料的开发及新型UPR及复合材料的制备方法,UPR测试方法及力学性能的改进。     

2007-2008年国外不饱和聚酯工业进展

综述了2007-2008年国外不饱和聚酯(UPR)的生产、供应和消费情况。介绍了UPR胶衣树脂及制品、UPR复合材料研究应用进展,UPR环保新工艺及在提高UPR阻燃性及力学性能方面的技术进展。     

不同纳米粒子改性不饱和聚酯树脂的对比研究

分别采用纳米二氧化硅、纳米蒙脱土及其复配体系改性不饱和聚酯树脂(UPR),对比研究了不同样品的弯曲性能、冲击性能及吸水性能。结果表明:纳米蒙脱土质量分数为3%的样品的弯曲强度及冲击强度均明显低于含纳米二氧化硅的样品,但模量值却正好相反。选用2种纳米粒子按不同比例复配后,可使UPR弯曲模量及冲击强度得到进一步提高,但对弯曲强度无积极效果。温度对吸水率及吸水平衡存在显著影响,升高温度,所有样品的吸水率急剧增大,更加不容易达到吸水平衡。     

Development of unsaturated polyester matrix – carbon nanofibers nanocomposites with improved electrical properties

In this work, the dispersion of carbon nanofibers (CNFs) in an unsaturated polyester (UP) resin was performed by mean of the calendering process. The calendering process allows to obtain good dispersion of the nanoparticles, and, with respect to the other techniques, is also possible to scale it up at the industrial level. Optimization of the calendering conditions for the processing was carried out as a first step of this study. Optimization, in this case, means to reach the best dispersion level, as rapidly as possible and with the lowest amount of styrene evaporation. The dispersion level reached was investigated by the technique of scanning electron microscopy. The investigation on electric conductivity of the nanocomposites at different CNF concentrations has revealed that the electrical percolation threshold exists at around 0.3 wt %, where electrical conductivity switches from 10^?13 to 10^?7 S/cm. The rheological characterization has been performed to verify if the improved electrical properties are obtained at the expense of loss of workability, that is a significant increase of viscosity. Eventually, a mechanical characterization was carried out. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Utilization of flyash as filler for unsaturated polyester resin

Flyash is an inexpensive material that can reduce the overall cost of the composite if used as a filler for unsaturated polyester resin (PR). Flyash-filled unsaturated polyester resin (FPR) was cast into sheets. The tensile strength, flexural strength, and flexural modulus were determined. Calcium carbonate-filled polyester resin (CPR) and PR were also cast into sheets. The above-mentioned properties were determined and a comparison was made. The filler concentration was varied from 0 to 15 wt %. It was found that FPR was inferior to CPR and PR composites with respect to tensile and flexural strengths. But FPR was found to have a higher flexural modulus than those of CPR and PR. FPR with 10% flyash was found to have poor acid and solvent (benzene) resistances and good saltwater, alkali, weathering, and freeze–thaw resistances as seen from the mechanical properties. The possible ways of improving the strength of FPR are discussed. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 1385–1391, 1998     

2008-2009年国外不饱和聚酯工业进展

介绍了2008-2009年国外不饱和聚酯树脂(UPR)企业的运营情况,主要原材料(苯酐、顺酐)的市场概况,综述了UPR复合材料的研究及应用进展,新型不饱和聚酯的开发以及树脂力学性能方面的改进研究进展。     

2005-2006年国外不饱和聚酯树脂工业进展

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。     

Wear and mechanical properties of reactive thermotropic liquid crystalline polymer/unsaturated polyester/glass fiber hybrid composites

To improve the performance of unsaturated polyester (UP) under cold‐heat alternate temperature, self‐synthesized reactive thermotropic liquid crystalline polymer (TLCP)‐methacryloyl copolymer (LCMC), UP, and glass fiber (GF) hybrid composites was prepared by molding technology. The apparent activation energy and crystal behavior analysis of LCMC/UP blends were investigated by Differential scanning calorimetry and X‐ray diffraction (XRD), respectively, the results showed that the addition of LCMC can reduce apparent activation energy and accelerate the curing reaction of UP, the XRD analysis indicated that the crystal phase of LCMC still exist in the blends after blending with UP. The effect of LCMC content on the properties of LCMC/UP/GF hybrid composites such as impact strength, bending strength, and ring‐on‐block wear were also investigated through static mechanical tests and wear tests. The mechanical properties of hybrid composites increased significantly because of the addition of LCMC. The wear tests showed that LCMC can improve the wear resistance of the UP/GF/LCMC hybrid composites even though the content of LCMC was at a relatively low level (5–7.5 wt %). This makes it possible to develop novel kind of UP‐based materials with good wear resistance for various applications. The Worn surface was observed by scanning electron microscopy (SEM) and the mechanism for the improvement is discussed in this paper. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3899–3906, 2007     

HTPB引入方式对不饱和树脂改性效果的影响

以高顺式端羟基液体顺丁橡胶（HTPB）为改性剂,分别采用共混-共固化法、共缩聚法制备了共混改性型不饱和聚酯[UPR+HTPB(blend)]、无规共缩聚改性型不饱和聚酯（UPR-HTPB）和嵌段共缩聚改性型不饱和聚酯（UPR-MAH-HTPB）,系统地考察了三种改性不饱和聚酯固化样品的机械物理性能。结果表明,三种改性不饱和树脂的断裂伸长率、拉伸强度和冲击强度均优于未改性的不饱和树脂,固化收缩率大幅降低,且共缩聚改性树脂（UPR-HTPB和UPR-MAH-HTPB）的增韧效果和降收缩效果明显优于共混改性树脂。此外,UPRMAH-HTPB的拉伸模量也优于未改性的不饱和树脂,硬度和热变形温度则基本保持不变。冲击断面的形貌、交联密度和DMA分析表明,UPR+HTPB(blend)固化体系中存在着HTPB聚团的现象,而共缩聚改性树脂,尤其是嵌段型的UPR-MAH-HTPB,因HTPB嵌入到UPR的主链中,使HTPB微相分离,并更多地参与交联,在增韧的同时保持了树脂良好的刚性和强度。     

2010-2011年国际不饱和聚酯树脂工业进展

介绍了2010-2011年国际原油市场、不饱和聚酯部分项目投产及企业并购情况。综述了UPR领域的研究及应用进展,包括UPR的改性、力学性能的改进、老化机理、生物复合材料、新型不饱和聚酯复合材料及其应用。     

2006-2007年国内外不饱和聚酯树脂工业进展

综述了2006-2007年国内外不饱和聚酯树脂和原料的生产、供应、消费以及产能扩充情况。介绍了不饱和聚酯复合材料研究及应用进展、不饱和聚酯节能降耗、环保新工艺及在提高不饱和聚酯树脂力学性能、耐热性、防腐蚀性、阻燃性方面的研究进展以及新型水性光固化不饱和聚酯树脂。     

Behavior of nonazeotropic compositions of a styrene–unsaturated polyester resin analyzed through FTIR spectroscopy and dynamic mechanical thermal analysis

Styrene is one of the comonomers most frequently used in the curing of unsaturated polyester resins. The use of nonazeotropic compositions leads to the formation of networks, in which the styrene–polyester ratio varies significantly during curing, as shown through FTIR spectroscopy. Dynamic mechanical thermal analysis (DMTA) showed how the variation in the styrene content affects the network structure that is formed. The results showed a decrease in network density in the systems in which the azeotropic composition was not used. The styrene content is therefore a factor that governs the curing process, in addition to the ultimate properties of the cured resins. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3618–3625, 2003     

利用废聚酯薄膜制备不饱和聚酯树脂工艺研究

以废聚酯薄膜(PET)为原料制得了不饱和聚酯树脂(UPR),通过产物酸值测定研究了反应温度、催化剂种类对聚酯薄膜降解反应的影响,通过固化性能测试及其浇注体和玻璃钢制品的力学和热性能测试确定了废聚酯薄膜的用量,并将制品的性能与邻苯型196#不饱和聚酯树脂作了比较。结果表明:采用有机锡类和醋酸锌的复合催化剂,反应温度210～225℃,废聚酯薄膜与顺丁烯二酸酐物质的量比1:2.7时UPR产品性能最优,其力学性能、耐热性和耐腐蚀性均优于196#UPR。