Ionic liquid-assisted preparation of hydroxyapatite and its catalytic performance for decarboxylation of itaconic acid

The synthesis of methacrylic acid from biomass-derived itaconic acid is a green route,for it can get rid of the dependence on fossil resource.In order to solve the problems on this route such as use of a preciousmetal catalyst and a corrosive homogeneous alkali,we prepared a series of hydroxyapatite catalysts by an ionic liquid-assisted hydrothermal method and evaluated their catalytic performance.The results showed that the ionic liquid[Bmim]BF_(4) can affect the crystal growth of hydroxyapatite,provide fluoride ion for fluorination of hydroxyapatite,and adjust the surface acidity and basicity,morphology,textural properties,crystallinity,and composition of hydroxyapatite.The[Bmim]BF4 dosage and hydrothermal temperature can affect the fluoride ion concentration in the hydrothermal system,thus changing the degree of fluoridation of hydroxyapatite.High fluoride-ion concentration can lead to the formation of CaF_(2) and thus significantly decrease the catalytic performance of hydroxyapatite.The hydrothermal time mainly affects the growth of hydroxyapatite crystals on the c axis,leading to different catalytic performance.The suitable conditions for the preparation of this fluoridized hydroxyapatite are as follows:a mass ratio of[Bmim]BF4 to calcium salt=0.2:1,a hydrothermal time of 12 h,and a hydrothermal temperature of 130℃.A maximal methacrylic acid yield of 54.7%was obtained using the fluoridized hydroxyapatite under relatively mild reaction conditions(250℃ and 2 MPa of N_(2))in the absence of a precious-metal catalyst and a corrosive homogeneous alkali.

Influence of Ca/P ratio on the catalytic performance of hydroxyapatite for decarboxylation of itaconic acid to methacrylic acid

Methacrylic acid,an important organic chemical,is commercially manufactured starting from fossil feedstock.The decarboxylation of itaconic acid derived for biomass is a green route to the synthesis of methacrylic acid.In view of the problems existing in the researches on this route such as use of noble metal catalyst,harsh reaction conditions and low desired-product yield,we prepared a series of hydroxyapatite catalysts with different Ca/P molar ratios and evaluated their catalytic performance.The results showed that the hydroxyapatite catalyst with a Ca/P molar ratio of 1.58 had the best catalytic activity.The highest yield of MAA up to 61.2%was achieved with basically complete conversion of itaconic acid under the suitable reaction conditions of 1 equivalent of NaOH,2 MPa of N_(2),250℃,and 2 h.On this basis,a reaction network for the decarboxylation of itaconic acid to methacrylic acid catalyzed by hydroxyapatite was established.With the aid of catalyst characterization using X-ray powder diffraction,NH3/CO2 temperature-programmed desorption,N_(2)physisorption,inductively coupled plasma optical emission spectrometry,and scanning electron microscopy,we found that the distribution of surface acid sites and basic sites,crystal growth orientation,texture properties and morphology of hydroxyapatite varied with the Ca/P molar ratio.Furthermore,the change of the crystal growth orientation and its influence on the surface acidity and alkalinity were clarified.

Microwave-Assisted Synthesis of Poly(Aspartic Acid-Itaconic Acid) Copolymer and Its Characterization

Poly(aspartic acid-itaconic acid) copolymer was synthesized from aspartic acid(Asp) and itaconic acid(Ita) under microwave irradiation. The effects of microwave power, microwave irradiation time, molar ratio of itaconic acid and aspartic acid, catalyst type, catalyst and organic solvent content on copolymer yield, and the performance for inhibition of CaCO_3 fouling were investigated. It was found that the product yield achieved a highest record of 95% when the amount of catalyst Na H_2PO_4 was 0.012 mol, the amount of organic solvent propylene carbonate was 16 m L, the molar ratio of Asp/Ita was 3:1, the microwave output power was 1200 W and the irradiation time was 5.5 min. And the product performance for inhibition of calcium carbonate also reached a highest value of 94.38%. Structural characterization of the product showed that the product was the aspartic acid-itaconic acid copolymer.

Investigation of the Reaction Mechanism of Itaconic Acid/Maleic Acid Copolymer System and Cotton Cellulose

The reaction mechanism of IA/MA copolymer system andcotton cellulose is conjectured and verified, the two keysteps, such as the formation of cyclic anhydride interme-diates and the building of ester crosslinklng, and the ef-fect of sodium hypophosphite are especially emphasized,by FT - IR spectroscopy and acid- base titration anal-yses. The experiments reveal that carboxylic acids main.ly change to cyclic anhydride in the pre - drying step andSodium Hypophosphite (SHP) has effect on it, but mostester - crosslinkages are built in the curing step and SHPhas effects on both anhydride formation and ester -crosslinking formation.

Kinetics of Maleic Acid/Itaconic Acid In-situ Polymerization on Cotton

Cotton fabric samples are padded with maleic acid (MA) and itaconic acid (IA) finishing bath in the presence of potassium persulfate (K 2S 2O 8), and then dried at different temperatures for different time intervals. The portion of unreacted monomers on cotton fabric samples is determined by means of measuring the double bond content. The kinetic data (rate constants, Arrhenius activation energy, frequency factor) of the in-situ polymerization have been calculated.

Synthesis and Characterization of the Terpolymer of Itaconic Acid with Acrylamide and 2-Acrylamido-2-methylpropanesulfonic Acid

The terpolymer of itaconic acid, acrylamide and 2-acrylamido-2-methyl-1-propane sulfonic acid was synthesized through the free-radical polymerization. The IR spectra confirmed that there was no olefinic band, while the TGA results revealed that the terpolymer was of high thermal stability.

Preparation and Characterization of Functionalized Polypropylene with Acrylamide and Itaconic Acid

Functionalized polypropylene with acryl amide (AAm) and itaconic acid (IA) were prepared in the molten state in the presence of dicumyl peroxide. The effects of the concentration of both mono- mers on the degree of functionalization and properties of the products were investigated by FT-IR, contact angle measurement and DSC analysis. It was found that the degree of functionalization depends on the initial concentration of both monomers that used in the reaction. The influence of the AAm and IA content on the melting and crystallization temperature of PP was investigated by DSC. The contact angle of water on film surfaces of the functionalized PP (PP-g-AAm and PP-g-IA) decreased with increasing modified polymer content. From FT-IR spectra of functionalized PP a calculation was made of carbonyl index on the films surfaces. It was found that the higher intensity of the carbonyl index, the lower contact angle value and the lower crystallinity confirmed the ex- istence of functionalized AAm and/or IA in PP. It was concluded from the different characteriza- tion methods that the polarity and percentage of functionalized PP were increased up to 3 phr for both monomers, and then it was decreased by increasing the amount of monomers and had a threshold value, due to nucleating agents of monomers in PP.

Directional Breeding of High Itaconic Acid Yielding Strain of <i>Aspergillus terreus</i>with a New Plate Technique

Itaconic acid is commercially produced by the cultivation of Aspergillus terreus using starch hydrolysate as carbon source. The degree of hydrolysis had a great influence on itaconic acid production which was suitable when corn starch was saccharified at 35 DE. The α-amylase was sufficient to drive the starch hydrolysis to the degree. The agar plate assay with LiCl treatment provided a rapid, simple and unequivocal method for screening large numbers of colonies for itaconic acid producing strains. It was learned by experience that the strains on the plates with thick hyphae and light-colored spores often accompanied high itaconic acid production. A strain, designated Ast165, producing itaconic acid with a high yield, was successfully obtained by directional breeding of metabolic end products resistant strains. The itaconic acid concentration produced by Ast165 was 53.8 g/l from 100 g/l of starch hydrolysate in shake flasks. The conversion rate was 61.3%, which was the highest value found in tests.

Synthesis and Characterization of Poly(N-Vinyl-2-Pyrrolidone/Itaconic Acid) Hydrogel

With N-vinyl-2-pyrrolidone (NVP) and itaconic acid(IA), poly(N-vinyl-2-pyrrolidone/itaconic acid)[P(NVP/IA)] hydrogel was synthesized by free radical solution polymerization. The structure of this (P(NVP/IA)) was characterized by IR. Effects of concentration of itaconic acid, amount of cross-link agent, N,N′-methylene-bis-acrylamide, reaction temperature, and time on properties of swelling ratio(SR) of the hydrogel were investigated.The results show that the best swelling property of the hydrogel is obtained at 50 ℃ and 1.5 h. pH sensitivity increases as the concentration of itaconic acid in the hydrogel system increases. Swelling ratio of the hydrogel decreases as the amount of cross-link agent increases.

Hydrolysate of corn starch saccharified with a dual-enzyme system and the effect on the crystallization of itaconic acid when used in fermentation

An improved process of hydrolysis of corn starch was adopted in the production of itaconic acid （IA）, the aim was to decrease the unfermentable reducing sugar （RS） in the medium from the beginning of the fermentation and to increase the crystallization efficiency of IA from the fermentation broth. The glucose （GS） syrups saccharified by several combinations of glucoamylase and pullulanase were investigated and used as the carbohydrate source of the fermentation medium for the spore-initiated submerged fermentations experiments. Compared with the conventional process （with pullulanase controlled）, the improved process decreased th.e RS residue in the fermentation broth from 3.01g/L to 1.35g/L and from 4.25g/L to 3.25g/L when the original RS of the medium were 100 and 120g/L, respectively. The crystallization efficiency of IA increased from 65% to 78.8% and from 69.58% to 82.81% with the original RS being 100 and 120g/L, respectively.

IA-AMPS-HEMA在反渗透法处理地热尾水结垢问题中的应用

地热水回灌过程中存在高盐尾水影响地热流体的化学成分并堵塞地热水的运移通道现象。首先分析了地热尾水水质特征,根据地热尾水回灌时发生堵塞现象的机理和阻垢剂的阻垢机理,合成了一种适用于反渗透膜工艺的羧酸型共聚物阻垢剂IA-AMPS-HEMA,通过红外光谱图发现了共聚物的结构官能团种类丰富,并含有多个羧酸基团。扫描电镜(SEM)分析表明,共聚物能有效预防碳酸钙垢生成。通过试验探明低剂量的IA-AMPS-HEMA阻垢效果远优于市售阻垢剂,达到了97.6%。利用一套添加了阻垢剂预处理装置的反渗透系统,去除地热尾水中的难溶性无机盐沉淀物,使地热回水能达到回灌和补水要求。经设备连续运行,证明了添加IA-AMPS-HEMA对于反渗透装置处理地热尾水是可行的,对Ca2+、Ba2+、Mg2+等硬度离子和腐蚀性盐类去除率达到了95%以上,减少了地热尾水中难溶性沉淀物的凝聚,满足了地热井补水水质要求,同时有效避免了硬垢对反渗透膜表面的损伤,延长了反渗透膜的使用时间,降低了设备的运行成本。

绿色水处理药剂的合成及其与静电场协同性能研究

采用不含磷氮的药剂衣康酸(IA)和甲基丙烯磺酸钠(SMAS)合成了环保型的两元共聚物药剂,并系统研究了合成工艺条件对共聚物性能的影响。最终得到最佳合成条件如下:原料质量比(IA∶SMAS)为2∶1,聚合温度为95℃,聚合时间为6 h;此外,引发剂和链转移剂的添加量均为原料总质量的5%。经静态阻垢实验研究表明,合成的共聚物具有优异的阻垢性能和分散性能。将该共聚物与静电场结合用于阻垢性能研究,结果表明静电场的存在使IA/SMAS的阻垢性能提高了17%,静电与IA/SMAS共聚物具有协同增效作用。

衣康酸聚乙二醇单醚酯封端水性聚氨酯织物涂层剂的制备及其性能

为丰富水性聚氨酯亲水单体的来源与种类,从而提高涂层织物水蒸气透过率,以聚乙二醇单醚(MPEG)和衣康酸(IA)为原料,通过酯化反应合成含碳碳双键的衣康酸聚乙二醇单醚酯(IM)。将IM和甲基丙烯酸羟乙酯型水性聚氨酯(HWPU)混合,经紫外线接枝得到IM封端水性聚氨酯织物涂层剂(WPU-IM),采用直接涂覆法将其涂布于涤纶织物。通过吸水率、拉伸、耐静水压和水蒸气透过率测试对WPU-IM涂膜、织物涂层的性能进行分析。结果表明:当IM质量分数为2.1%时,WPU-IM涂膜断裂强度为8.61 MPa,断裂伸长率为325%,吸水率为17.4%,水接触角为79.2°;WPU-IM涂层织物耐静水压值为18.86 kPa,透湿率为4086.3 g/(m^(2)·d),综合性能达到最佳。

MA/IA/SAS/St四元共聚物超分子分散剂的制备及性能

通过自由基共聚反应在氧化还原体系中制备了具有两亲结构的水溶性四元超分子聚合物（SPMISS）。探讨了工艺条件对陶瓷悬浮体系性质的影响,得到SPMISS的最佳合成工艺条件为：在氧化还原体系中,n（衣康酸）∶n（烯丙基磺酸钠）∶n（甲基丙烯酸）∶n（苯乙烯）=1.0∶1.0∶1.3∶0.1,选择十二硫醇为链转移剂,反应温度80℃,反应时间2.5 h。通过IR、XRD对聚合物的结构、组成及性质进行了表征,对黏土浆料的流变性和SEM图进行了考察。结果表明：四元超分子分散剂SPMISS中含有大量的-OH,-SO3H和苯环,可显著优化陶瓷浆料的流变性和稳定性,pH=9～11时,其最佳用量为w（SPMISS）=0.34%（相对于绝干料）。

MPEGMA-SMAS-IA三元共聚减水剂的合成及性能

以MPEGMA(马来酸单聚乙二醇单甲醚酯)、SMAS(甲基丙烯磺酸钠)和IA(衣康酸)等为主要原料,通过分子结构设计合成了MPEGMA-SMAS-IA三元共聚的聚羧酸系减水剂,并考察了单体配比、引发剂含量和聚合时间等对其性能的影响。研究结果表明:当n(MPEGMA):n(SMAS):n(IA)=1:0.9:0.2、聚合温度为80℃、聚合时间为5 h和w(引发剂)=10%(相对于单体总质量而言)时,聚羧酸系减水剂的综合性能相对较好;以此作为改性剂,当w(减水剂)=0.33%(相对于水泥质量而言)、水灰比为0.29时,改性水泥净浆的流动度(272 mm)相对最大。

IA/MA/AMPS三元共聚物阻垢剂的合成研究

以衣康酸(IA)、丙烯酸甲酯(MA)和2-丙烯酰胺基-2-甲基丙磺酸(AMPS)为单体,过硫酸铵为引发剂,采用水溶液自由基聚合方法合成了一种三元共聚物阻垢剂。经过单因素实验对影响共聚物阻垢性能的因素进行优化后,确立了最佳反应条件。通过静态法对三元共聚物的阻垢性能进行评价,在共聚物加剂量为50 mg/L时,对CaCO3的阻垢率最佳可达91.4%,并用红外光谱和扫描电子显微镜对共聚物的结构和Ca CO3垢样进行了分析。

新型阻垢剂IA-SSS-MA聚合物的合成与表征

以衣康酸(IA)、苯乙烯磺酸钠(SSS)和马来酸酐(MA)为单体,以水为溶剂,过硫酸铵作引发剂,合成了衣康酸-苯乙烯磺酸钠-马来酸酐(IA-SSS-MA)三元聚合物阻垢剂,考察了单体配比、反应温度、引发剂量、滴加时间等对聚合物阻碳酸钙垢效果的影响,结果表明:当单体配比为IA∶SSS∶MA=5∶1∶0.25(摩尔比),反应温度100℃,引发剂量占单体总量13%,滴加时间为5 h,阻碳酸钙垢效果最好,阻垢率达到98.11%。

IA-HPEC共聚物阻垢剂的制备及阻垢性能

以异丁烯醇聚氧乙烯醚(HPEG)、衣康酸(IA)为原料,在过硫酸铵-次亚磷酸钠引发剂作用下进行自由基共聚,合成阻垢剂IA-HPEC。采用FT-IR、1 H-NMR等方法表征IA-HPEC阻垢剂结构,采用扫描电镜(SEM)观察阻垢后形成的CaCO3晶体形貌。通过静态阻垢性能实验,考察了单体配比、聚合条件、氧化剂滴加方式及用量对合成的IA-HPEC阻垢剂阻垢性能的影响。结果表明,在m(IA)/m(HPEC)=1、聚合温度110℃、聚合时间1.5h、分批滴加氧化剂的最佳聚合条件下,合成的共聚物IA-HPEC对CaCO3的阻垢率为93.9%,优于市场含磷阻垢剂,具有较好的经济与环境效益。

IA/MA/MAA/AMPS共聚物阻垢剂的合成及阻垢性能

以衣康酸、丙烯酸甲酯、甲基丙烯酸、2-丙烯酰胺基-2-甲基丙磺酸为单体,通过水溶液聚合的方法合成了新型四元共聚物阻垢剂,并通过红外光谱确定了共聚物结构。探讨单体配比、反应时间、引发剂用量对共聚物阻垢性能的影响。将合成共聚物与市售阻垢剂进行分散氧化铁性能对比试验,结果表明:该四元共聚物的分散氧化铁性能优于市售阻垢剂,在共聚物质量浓度为40 mg/L时,对Ca CO3的阻垢率为92.7%,对Ca3(PO4)2的阻垢率为88.5%。

IAS型高分子表面活性剂的合成及应用

以衣康酸(IA)和月桂醇聚氧乙烯醚(AEO-9)为原料,制备出一种可用于合成高分子表面活性剂的单体月桂醇聚氧乙烯醚衣康酸单酯(IAEO),将其与丙烯酸(AA)、甲基丙烯磺酸钠(SMAS)进行聚合反应,合成了一系列IAS型高分子表面活性剂并将其用于废纸脱墨。考察了最佳合成工艺及复配条件,并测定了其表面化学性能。结果表明,当酯化时间4 h,酯化温度125℃,n(IA)∶n(AEO-9)=1∶1.06,催化剂用量6.5%;聚合时间5.5 h,聚合温度85℃,n(IAEO)∶n(AA)∶n(SMAS)=1∶2∶1,引发剂用量1.5%时获得的IAS型表面活性剂具有较佳的脱墨效果,且乳化性能及分散性能优于AEO-9。将IAS型高分子表面活性剂与壬基酚聚氧乙烯醚(TX-10)按质量比1∶2复配时(复配表面活性剂总质量占绝干浆质量的0.2%),脱墨效果进一步提高,脱墨浆白度较单独使用IAS型高分子表面活性剂时提高2.3个百分点,残余油墨量下降12.9 mm2/m2。