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1.
Mihail Ionescu Zoran S. Petrović Xianmei Wan 《Journal of Polymers and the Environment》2007,15(4):237-243
Soybean polyols prepared by ring opening reactions of epoxidized soybean oil with hydrogen active compounds (water, alcohols,
organic or inorganic acids, thiols, hydrogen etc.) have a low reactivity in the reaction with isocyanates because the hydroxyl
groups are secondary. This paper presents a simple and convenient method to increase the reactivity of soybean polyols with
secondary hydroxyl groups by ethoxylation reactions with the preservation of triglyceride ester bonds. The method uses mild
reaction conditions: low alkoxylation temperature of 35–45 °C, low pressure of 0.1–0.2 MPa (15–30 p.s.i.) and a superacid
as catalyst (HBF4). The new soybean polyols have a higher reactivity toward isocyanates in polyurethane formation due to the high percentage
of primary hydroxyl groups. The primary hydroxyl content was determined by the second order kinetics of polyol reaction with
phenyl isocyanate. 相似文献
2.
Novel Biobased Polyurethanes Synthesized from Soybean Phosphate Ester Polyols: Thermomechanical Properties Evaluations 总被引:2,自引:0,他引:2
J.-P. Latere Dwan'Isa A. K. Mohanty M. Misra L. T. Drzal M. Kazemizadeh 《Journal of Polymers and the Environment》2003,11(4):161-168
Biobased polyurethanes from soybean oil–derived polyols and polymeric diphenylmethane diisocyanate (pMDI) are prepared and their thermomechanical properties are studied and evaluated. The cross-linked biobased polyurethanes being prepared from soy phosphate ester polyols with hydroxyl contents ranging from 122 to 145 mg KOH/g and pMDI within 5 min of reaction time at 150°C in absence of any catalyst show cross-linking densities ranging from 1.8 × 103 to 3.0 × 103
M/m3, whereas glass transition temperatures vary from approximately 69 to 82°C. The loss factor (tan ) curves show single peaks for all these biobased polyurethanes, thus indicating a single-phase system. The storage moduli (G) at 30°C range from 4 × 108 to 1.3 × 109 Pa. Upon postcure at 150°C, the thermomechanical properties can be optimized. Cross-link densities are improved significantly for hydroxyl content of 139 and 145 mg KOH/g at curing time of 24 h. Similarly, glass transition temperature (Tg) and storage moduli around and after Tg are increased. Meanwhile, tan intensities decrease as result of restricted chain mobility. Longer exposure time (24 h) induces thermal degradation, as evidenced by thermogravimetric analysis (TGA). The dynamic mechanical (DMA) analysis shows that postcure at 100°C for times exceeding 24 h also leads to improved properties. However, cross-linking densities are lower compared to postcure carried out at 150°C. 相似文献
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Uldis Stirna Anda Fridrihsone Brigita Lazdiņa Marija Misāne Dzintra Vilsone 《Journal of Polymers and the Environment》2013,21(4):952-962
Biobased polyols were synthesized from rapeseed oil (RO) with diethanolamine (DEA), triethanolamine (TEA) and glycerol (GL) at different molar ratios. The structures of the synthesized polyols were analyzed using FTIR-ATR spectroscopy. Polyurethane (PU) networks from RO/DEA polyols and polymeric MDI showed higher tensile strength, modulus and hardness, but their elongation at break decreased, compared to the case of the PU obtained from RO/TEA and RO/GL polyols. The tensile strength and modulus of PU networks increased with increasing PU cohesion energy density (CED) and decreasing molecular weight between crosslinks M c . From the thermogravimetric analysis and its derivative thermograms, at the first stage of destruction (below 5 % weight loss) in the air and inert atmosphere, the PU obtained from RO polyols were ranked in the following order: PU RO/GL > PU RO/TEA > PU RO/DEA, and their thermostability was higher than that of the PU based on propylene oxide. 相似文献
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采用振荡培养实验和活性污泥模拟实验对大豆油乙氧基化合物(SOE)进行了生物降解研究。实验结果表明,振荡培养实验中SOE的初级生物降解度随平均环氧乙烷加成数的增多而略有下降,且SOE-4,SOE-10,SOE-20的初级生物降解度在第6天时分别为97.3%,91.1%,89.4%;活性污泥模拟实验中SOE的初级生物降解度随平均环氧乙烷加成数的增多而增加,且SOE-4,SOE-10,SOE-20的初级生物降解度在第8天时分别为29.0%,81.2%,100.0%。用激光粒度仪测量SOE水合物在不同静置时间时的粒径分布及分散度结果表明,随静置时间的延长,平均环氧乙烷加成数少的SOE水合物粒径逐渐增大,且分散性或水溶性变差,易产生团聚导致初级生物降解度降低。对水溶性或分散性较差的表面活性剂,建议以振荡培养实验研究其生物降解性较为恰当。 相似文献
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考虑离散油滴在油田废水除油过程中发生的油滴碰撞聚结现象,模拟得出斜板除油器内全部油滴的动态信息,用于斜板除油器除油效率的计算.对矩形同向流斜板除油过程的模拟研究表明:油滴的碰撞聚结会增加斜板除油的效率;当废水的原始含油浓度增大时,斜板除油的效率会增大,碰撞聚结对除油效率提高的影响也越大;废水流动速度提高及斜板的倾斜角度增加均会使斜板的除油效率降低,但此时油滴碰撞聚结对除油效率的影响仍很明显. 相似文献
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Subrata Mondal Paul Memmott Darren Martin 《Journal of Polymers and the Environment》2012,20(2):326-334
In this paper we explore the preparation of polyurethanes from spinifex resin biopolymer. Polyurethanes were prepared by both one-shot and pre-polymer (two step) processes. Attenuated total reflection??Fourier transform infrared analysis revealed urethane bond formation in both processes, and the peak intensity for N?CH stretching was more sharp when the network was prepared by the pre-polymer method. Gel permeation chromatography revealed that the molecular weight of synthesized polyurethane increased with respect to the resin starting material, and the molecular weight was further increased when polyurethane was synthesized by the pre-polymer method. The glass transition temperature was also increased for the polyurethanes as compared with the starting resin. Thermo-gravimetric analysis revealed that the thermal stability of the PU-spinifex resin was reduced at intermediate temperatures due to the urethane bond formation. However, thermal degradation properties were superior at higher temperatures due to the cyclization degradation reaction of spinifex-polyurethane. 相似文献
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The aim of this study was to investigate the application of grapeseed oil, a waste product from the wine industry, as a renewable feedstock to make polyesters and to compare the properties of these materials with those derived from soybean and rapeseed oils. All three oils were epoxidized to give renewable epoxy monomers containing between 3.8 and 4.7 epoxides per molecule. Polymerisation was achieved with cyclic anhydrides catalysed by 4-methyl imidazole at 170 and 210 °C. Polymers produced from methyl tetrahydrophthalic anhydride (Aradur917®) had greater tensile strength and Young’s Modulus (tensile strength = 12.8 MPa, Young’s Modulus = 1005 MPa for grapeseed) than methyl nadic anhydride (MNA) derived materials (5.6 and 468 MPa for grapeseed) due to increased volume of MNA decreasing crosslink density. Soybean and grapeseed oils produced materials with higher tensile strength (5.6–29.3 MPa) than rapeseed derived polyesters (2.5–3.9 MPa) due to a higher epoxide functionality increasing crosslinking. T g’s of the polyesters ranged from ?36 to 62 °C and mirrored the trend in epoxide functionality with grapeseed producing higher T g polymers (?17 to 17 °C) than soybean (?25 to 6 °C) and rapeseed (?36 to ?27 °C). Grapeseed oil showed similar properties to soybean oil in terms of T g, thermal degradation and Young’s Modulus but produced polymers of lower tensile strength. Therefore grapeseed oil would only be a viable substitute for soybean for low stress applications or where thermal properties are more important. 相似文献
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大豆种皮过氧化物酶在酚类废水处理中的应用 总被引:1,自引:0,他引:1
介绍了大豆种皮过氧化物酶(SBP)的特性、除酚原理及用SBP处理酚类废水的研究进展,对SBP除酚的主要技术参数进行了详细阐述,并对现存问题和解决途径进行了探讨。SBP的性质优异、酶源丰富、价格低廉。直接用大豆种皮处理废水的经济指标已基本达到实用水平,但导致废水中可溶性固形物的含量增加,解决的途径是选育酶活性高、稳定性好的大豆品种。 相似文献
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研究了采用柴油低温临界吸收法回收装车挥发油气的效果。实验结果表明:按装车挥发油气中的总烃体积分数为20.88%、装车挥发油气流量为280 m3/h、年运行时间为2 668 h计,装置年回收油气量为291 t,装置年最大运行功率为206.770 MW,装置投资回收期为3 a;处理后净化气中的总烃体积分数为1.24%,排放质量浓度低于25 g/m3,油气回收率达95%。处理后净化气满足GB 20950—2007《储油库大气污染物排放标准》,取得了较好的环保效益和经济效益。 相似文献
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提出了水域泄漏油品回收技术的装备需求,介绍了水域泄漏油品问收处理措施.采用拦油栅来控制漂浮在水上的油品,将泄漏油品集中在相对较小的区域内,并使水面的浮油层加厚,然后使用人工或机械对泄漏油品进行回收.对于水域中的少量泄漏油品,采用吸油材料来进行吸附.在油膜较薄,难以用机械方法回收的情况下,使用消油剂或固化剂进行处理.水域... 相似文献
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In this study, polyethylene terephthalate (PET) waste from post-consumer soft-drink bottles and crude glycerol from the biodiesel industry were used for the preparation of polyols and polyurethane foams. PET waste was firstly depolymerized by the glycolysis of diethylene glycol. The glycolyzed PET oligomers were then reacted with crude glycerol at different weight ratios to produce polyols via a series of reactions, such as esterification, transesterification, condensation, and polycondensation. The polyols were characterized by titration, viscometry, gel permeation chromatography (GPC), and differential scanning calorimetry. Subsequently, polyurethane (PU) foams were made via the reaction between the produced polyols and polymeric methylene-4,4′-diphenyl diisocyanate and were characterized by mechanical testing, scanning electron microscopy, and thermogravimetric analysis. Polyols from crude glycerol and their PU foams were also prepared to compare properties with those of polyols and PU foams from PET and crude glycerol. The influence of aromatic segments existing in glycolyzed PET and glycerol content on the properties of the polyols and PU foams was investigated. It was found that aromatic segments of polyols from glycolyzed PET helped increase their molecular weights and improve thermal stability of PU foams, while high glycerol content in polyols increased the hydroxyl number of polyols and the density and compressive strength of PU foams. 相似文献
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含油废水破乳除油的试验研究及工业应用 总被引:1,自引:0,他引:1
对3种含油废水进行了处理试验,验证了破乳剂的破乳除油效果,筛选了效果最佳的破乳药剂并进行了工业应用,取得令人满意的结果。 相似文献
17.
M. R. Patel J. V. Patel D. Mishra V. K. Sinha 《Journal of Polymers and the Environment》2007,15(2):97-105
In the past few decades, governments and international agencies have been placing more emphasis on the improvement of production
technique, working conditions and reduction of the toxic emission to the atmosphere. In this context aqueous polyurethane
dispersion was synthesized from depolymerised polyethylene terphthalate (PET) waste. 1,4-Butanediol was used in PET depolymerisation.
Polyurethane dispersion films were characterized using differential scanning calorimeter, Fourier transform infrared spectroscopy,
gel permeable chromatography, etc. Incorporation of PET waste in polyurethane dispersion was an added advantage in waste management
and produced better quality polyurethane dispersion. 相似文献
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Randal L. Shogren Zoran Petrovic Zengshe Liu Sevim Z. Erhan 《Journal of Polymers and the Environment》2004,12(3):173-178
The potential biodegradability of several vegetable oil-based polymers was assessed by respirometry in soil for 60–100 days at temperatures of 30–58°C. Films of soybean oil and linseed oil which were oxidatively polymerized (Co catalyst) on a kraft paper support were 90%–100% mineralized to CO2 after 70 days at 30°C. Mineralization of polymerized tung oil to CO2 was much slower than soy or linseed oils. Mineralization of epoxy resins made from epoxidized soybean oil (ESO) and aliphatic dicarboxylic acids was rapid while mineralization of similar resins made with a triacid (citric) was slower. There was no significant degradation of polyamine/ESO resins after 100 days at 58°C. Mineralization of the available carbon in vegetable oil polyurethanes and cationically polymerized ESO was less than 7.5% after 70 days at 30°C and 25 days at 55°C compared to 100% for soybean oil. From these results, it appears that triglycerides highly cross-linked with non-degradable linkages are not biodegradable to a significant extent while triglycerides cross-linked with hydrolysable bonds such as esters remain biodegradable. 相似文献