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1.
Water‐soluble sulfonated acetone–formaldehyde (SAF) resins were synthesized by the reaction among acetone, formaldehyde, and sodium bisulfite. The factors affecting the properties of SAF resins and optimum conditions of preparation were investigated. The SAF resins prepared under proper conditions have good water solubility and high performance as a superplasticizer used in concrete. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3248–3250, 2004  相似文献   

2.
水煤浆添加剂磺化丙酮-甲醛缩聚物的合成与性能   总被引:5,自引:0,他引:5  
以丙酮、甲醛、亚硫酸钠为原料合成磺化丙酮 甲醛缩聚物型水煤浆分散剂 (SAF),考察了亚硫酸钠用量、醛酮比等因素对水煤浆分散性能的影响,实验研究发现,亚硫酸钠、甲醛和丙酮的最佳摩尔比为n(亚硫酸钠 )∶n(甲醛)∶n(丙酮) =0 4∶2 1∶1 .05。用最佳摩尔比条件下合成的SAF制浆,在投加量为w(SAF) =0 8%时最高定黏浓度达 66% (干煤粉质量分数)。流变性实验研究发现,浆体属于假塑性流体,具有明显的触变性,并且浆体在 100s-1的固定剪切速率下剪切具有较好的抗剪切性。  相似文献   

3.
Three types of unsaturated polyester resins were synthesized from the glycolysis of polyethylene terephthalate (PET) plastic waste, considering environment, cost and properties for their applications. These synthesized unsaturated polyester resins could be used for various construction processes and materials such as no dig pipelining (NDR-1), pultrusion (PLR-1) and polymer concrete (PCR-1). PET was taken from common soft-drink bottles, and ethylene glycol (EG), diethylene glycol (DEG) and MPdiol glycol mixtures were used for the depolymerization at molar ratios. The glycolyzed PET 1 st products (oligomers) were reacted with maleic anhydride, phthalic anhydride and dicyclopentadiene (DCPD) (especially for polymer concrete) to form unsaturated polyester resins with mixed styrene. The lab scale (1–5 kg) and pilot plant scale-up tests (200 kg) were experimented to evaluate the processing characteristics, viscosity, acid number and curing behaviors. The main properties such as hardness, flexural strength, tensile strength, heat distortion temperature, elongation, and chemical resistance were determined based on the various uses of the three resins. Furthermore, the applicability and the properties of these developed resins were verified through many real application tests.  相似文献   

4.
用丙酮、甲醛、无水亚硫酸钠和水通过缩合反应制备了水煤浆分散剂SAF,并将其与木质素磺酸钠(木钠)进行复配,评价了分散剂对宁夏回族自治区羊场湾产煤的成浆性能。以表观黏度1 500 mPa.s为标准,采用复配分散剂(SAF∶木钠=1∶2)制备的水煤浆的最大成浆浓度为71%,而采用SAF、木钠制备水煤浆的最大成浆浓度分别为67%,63%;SAF、木钠和复配分散剂制得的水煤浆48 h均无沉淀产生,而三者制得水煤浆的72 h产生的析水率分别为6.0%,4.2%,2.4%,表明复配分散剂可提高煤的成浆浓度,降低析水率。  相似文献   

5.
弱酸性条件合成脲醛树脂工艺的探讨   总被引:1,自引:0,他引:1  
探讨了在弱酸性条件下合成低甲醛释放量的脲醛树脂工艺的可能性。同时,对不同pH值条件下合成脲醛树脂的工艺及其性能进行了研究,并采用傅立叶红外光谱和化学方法对脲醛树脂的官能团进行了分析,同时定性分析了不同pH值条件下合成树脂的热学性能。研究表明在弱酸性条件下合成脲醛树脂的树脂性能和其胶合板的力学性能达到国家标准并且其胶合板甲醛释放量达到GB/T17657—1999中的E,级标准。弱酸性条件下合成脲醛树脂的工艺不仅能降低生产成本,还能生产性能优异的脲醛树脂胶黏剂。  相似文献   

6.
In this work, the multiepoxy functional glycidyl ether (GE) modified urea‐formaldehyde (UF) resins were synthesized via a traditional alkaline‐acid process under low formaldehyde/urea (F/U) molar ratio. The synthesized resins were characterized by 13C magnetic resonance spectroscopy (13C‐NMR), indicating that GE can effectively react with UF resins via the ring‐opening reaction of epoxy groups. Moreover, the residual epoxy groups of GE could also participate in the curing reaction of UF resins, which was verified by Fourier transform infrared spectroscopy. The storage stability of GE‐modified UF resins and the thermal degradation behavior of the synthesized resins were evaluated by using optical microrheology and thermogravimetric analysis, respectively. Meanwhile, the synthesized resins were further employed to prepare the plywood with the veneers glued. For the modification on bonding strength and formaldehyde emission of the plywood, the influences of addition method, type, and amount of GE were systematically investigated. The performance of UF adhesives were remarkably improved by the modification of GE around 20–30% (weight percentage of total urea) in the acidic condensation stage during the resin synthesis. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013  相似文献   

7.
聚氨酯丙烯酸酯涂料的性能研究   总被引:4,自引:0,他引:4  
合成了具有不同玻璃化温度、羟值、酸值和相对分子质量的羟基丙烯酸树脂,并采用HDI多异氰酸酯作为固化剂,研究了羟基丙烯酸树脂对双组分聚氨酯涂料性能的影响,结果表明:玻璃化温度、羟值和酸值对聚氨酯涂料的适用期、干燥时间、漆膜硬度、凝胶率等有较大影响;相对分子质量对这些性能的影响较小;漆膜中苯乙烯含量越高,漆膜耐候性越差.  相似文献   

8.
采用4,4′-二氟二苯甲酮、对苯二酚为原料,以不同比例的碳酸钾和碳酸钠为复合成盐剂,二甲苯为脱水剂,二苯砜为溶剂成功制备了一系列聚醚醚酮(PEEK)树脂。通过傅里叶红外光谱和X射线衍射对PEEK树脂结构进行了表征,证明合成的样品是对苯二酚型PEEK树脂。其次,对所制样品分别进行力学性能、特性黏度、热性能测试,详细地探讨不同钾/钠比例的复合成盐剂对PEEK性能的影响。结果表明,所有样品均展示了优异的力学性能和热性能,其熔点和初始分解温度分别大于330℃和520℃,拉伸强度介于77~101 MPa。此外,当碳酸钾和碳酸钠的物质的量比为7∶3时,PEEK树脂的综合性能达到最优。  相似文献   

9.
Styrene (St) and maleic anhydride (MA) alternating copolymers with different molecular weights (MW) were synthesized via radical copolymerization. The copolymers were subsequently transferred into water-soluble maleic amic acid derivatives (SMAA) via the aminolysis of anhydride groups using (NH4)2CO3 as the ammonia sources. The synthesized polymers were applied as a new kind of macromolecular modifier and added into the reaction system during the synthesis of urea-formaldehyde (UF) resins via the traditional alkaline–acidic–alkaline three-step process. The UF resins modified with SMAA were characterized using Fourier Transform Infrared Spectroscopy (FT-IR), 13C nuclear magnetic resonance (13C-NMR) spectroscopy, and thermal gravimetric analysis (TGA). All the results confirmed the successful incorporation of SMAA chains into the crosslinking network of the UF resins. The modified UF resins were further employed as wood adhesives and the effect of synthesis parameters on their performance was investigated. Meanwhile, the influence of SMAA molecular weight (MW) on the properties of the modified UF resins was also studied. When the UF resins were synthesized with a low molar ratio of formaldehyde/urea (F/U) and a predetermined amount of SMAA added into the reaction system at the second step, plywood bonded using these modified UF resins showed much improved bonding strength (BS) and depressed formaldehyde emission. Moreover, the as-modified UF resins showed good storage characteristics.  相似文献   

10.
Melamine can be incorporated in the synthesis of urea‐formaldehyde (UF) resins to improve performance in particleboards (PB), mostly in terms of hydrolysis resistance and formaldehyde emission. In this work, melamine‐fortified UF resins were synthesized using a strong acid process. The best step for melamine addition and the effect of the reaction pH on the resin characteristics and performance were evaluated. Results showed that melamine incorporation is more effective when added on the initial acidic stage. The condensation reaction pH has a significant effect on the synthesis process. A pH below 3.0 results on a very fast reaction that is difficult to control. On the other hand, with pH values above 5.0, the condensation reaction becomes excessively slow. PBs panels produced with resins synthesized with a condensation pH between 4.5 and 4.7 showed good overall performance, both in terms of internal bond strength and formaldehyde emissions. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012  相似文献   

11.
研究了强度等级(C30和C45)、龄期(28 d和120 d)、矿物掺和料(矿粉和粉煤灰)质量掺量对掺有脂肪族高效减水剂(SAF)的混凝土抗碳化性能的影响,并建立了C30/C45混凝土在28 d/120 d龄期的碳化深度与矿粉/粉煤灰掺量比例之间的回归模型。结果表明:水胶比的降低、养护龄期的延长都能提高水泥石的密实度,从而提高抗压强度和抗碳化性能;混凝土抗碳化性能随矿粉掺量的上升、粉煤灰掺量的下降而提高;当矿粉掺量占胶凝材料质量的37.5%时,C30混凝土的抗碳化性能最佳;当矿粉掺量占胶凝材料质量的31.9%时,C45混凝土的抗碳化性能最佳;当龄期增加时,粉煤灰掺量比例越大则碳化深度的下降幅度越大;矿粉和粉煤灰掺量的相对比例变化时,对低强度混凝土的影响程度要大于高强度混凝土。  相似文献   

12.
The effects of the degree of sulfonation (DS) and molecular weight (MW) of sulfonated phenolic resins (SPF) on the flow properties of cementitious materials were investigated. SPF resin was prepared from phenol, formaldehyde, and sodium bisulfite through a four‐step reaction. It was found that an increase in either DS or MW would enhance the dispersion effects in the system. The results indicate that the fluidity of cement pastes and the workability of concrete increased with higher DS until the resin was fully sulfonated. For resins with sufficient sulfonation, the performance of cementitious materials would increase with increasing MW. Apparently, resins with MW of about 3 × 104 are most effective in promoting concrete properties in terms of workability and compressive strength. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 1762–1766, 2000  相似文献   

13.
磺化丙酮-甲醛缩聚物对碳化硅砂轮浆料的分散作用   总被引:1,自引:1,他引:0  
由自制的磺化丙酮-甲醛缩聚物(sulphonated acetone-formaldehyde plymer,SAF)作为分散剂制备了浇注碳化硅(SiC)砂轮水基浆料.通过红外光谱,简要分析了SAF的分散机理,并以含10%(质量含量)聚乙烯醇水溶液作为分散介质,研究了不同用量SAF和不同pH值对体系沉降性的影响.采用沉降法和吸光光度法评价了SAF在SiC浆料中的分散性能.结果表明:当SAF添加的质量分数为5%,pH为10左右,体系的相对沉降层高度和吸光度均达到最大,得到了分散稳定性较好的砂轮浆料.  相似文献   

14.
The synthesis, characterization, and coatings performance of a series of glycidyl carbamate (GC) resins synthesized from a hexamethylene diisocyanate biuret resin, glycidol, and alcohols were explored. The partial replacement of glycidol with alcohols was explored as a way to reduce the viscosity of multifunctional GC resins. Six modified GC resins were obtained by replacing one-third of the glycidol with alcohols and ether alcohols. The modified GC resins were characterized using FTIR and 13C NMR. The alcohol-modified GC resins had significantly lower viscosity than that of the control GC resin. The effect of amount of alcohol modifier on resin viscosity was also studied by making a series of resins with different levels of modifier. Both amine-cured and self-crosslinked coatings were prepared from the resins. Coating properties such as hardness, impact strength, methyl ethyl ketone double rubs, flexibility, and adhesion were studied. Differential scanning calorimetry and thermogravimetric analysis were also used to study the thermal properties of the coatings. The resin structures and their coating performance showed an excellent correlation. The coating performance was found to be governed by the type of modifier, structural compositions of the modifier in the resins, type of amine crosslinkers, and techniques of crosslinking used.  相似文献   

15.
Sustainable resol-type resins [phenol–furfural–glucose (PFuG), phenol–furfural (PFu), and phenol–glucose resins] were synthesized via alkali catalysis. The chemical structures of the PFuG resins, which had different molar ratios of glucose to furfural, were analyzed by 1H-NMR and Fourier transform infrared spectroscopy. A possible mechanism for formation of the PFuG resin was proposed. The crosslinking curing behaviors of the PFuG resins were examined by differential scanning calorimetry analysis. The performance of the PFuG resins as wood adhesives was studied. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47732.  相似文献   

16.
采用对苯二甲酸、间苯二甲酸和新戊二醇为主体,控制单元羧酸4-叔丁基苯甲酸(PTBBA)的加量,合成了具有不同分子结构的聚酯树脂,研究了PTBBA对聚酯树脂及其异氰尿酸三缩水甘油酯(TGIC)和羟烷基酰胺(HAA)2种体系粉末涂料的影响规律,采用差式扫描量热仪(DSC)、凝胶色谱仪(GPC)、傅立叶变换红外光谱(FT-I...  相似文献   

17.
合成了腰果酚改性酚醛树脂,对其进行了软化点及凝胶化时间的测定。并进一步用凝胶色谱分析了其分子量及分子量分布,探讨了它们之间的内在联系。  相似文献   

18.
介绍了多功能助剂PAE-206和DS-500的基本属性,合成了饱和聚酯树脂和热固性丙烯酸树脂,并分别制成卷材料涂料,对比是否加入多功能助剂时的涂膜性能。结果表明,多功能助剂能改善涂膜的T弯、硬度、耐MEK擦试、耐水煮性等。  相似文献   

19.
在加固混凝土用树脂体系的作用原理与特性要求基础上,通过大量实验研究,研制出底层树脂体系,找平材料和浸渍树脂体系,并改性得到相应的低温用环氧固化剂。性能测试表明,所合成的三种环氧权脂体系在加固修复工艺性和粘结性能等方面均满足了要求。三种树脂体系综合使用的性能满足碳纤维片材加固修复要求。  相似文献   

20.
Epoxy resins based on the triglycidyl ether of tris(hydroxyphenyl)methane (TETM) possess a very high heat distortion temperature and superior thermal oxidative stability over other types of epoxy resins. The high performance trifunctional epoxy resin (TETM) was synthesized by the condensation of a hydroxybenzaldehyde with phenol followed by epoxidation with a halohydrin. The structure of the synthesized TETM was confirmed by infrared (IR), mass spectra (MS), and nuclear magnetic resonance (NMR) spectroscopy. Amine terminated polydimethylsiloxanes (ATPDMS) were used to reduce the stress of trifunctional epoxy resin cured with phenolic novolac resin for electronic encapsulation applications. The dispersed silicone rubbers effectively reduce the stress of cured epoxy resins by reducing the coefficient of thermal expansion (CTE) and flexural modulus, while the glass transition temperature (Tg) is depressed by only a small amount.  相似文献   

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