Characterization of barium titanate reinforced acrylonitrile butadiene rubber composites for flexible electronic applications: influences of barium titanate content

The aim of this study was to develop high dielectric constant flexible polymers with a highly efficient and cost‐effective approach using acrylonitrile butadiene rubber (NBR) as the polymer matrix and barium titanate (BT) as the high dielectric constant filler. The BT powder was synthesized with a solid‐state reaction and was characterized using a particle size analyzer, XRD, SEM and Fourier transform infrared spectroscopy. NBR/BT composites were fabricated using an internal mixer with various BT loadings up to 160 phr. The influence of BT loading on the cure characteristics and mechanical, dynamic mechanical, thermal, dielectric and morphological properties was determined. The incorporation of BT in the NBR matrix shortened scorch time and increased delta torque. The mechanical properties, thermal stability and dielectric constant were greatly improved and increased with BT loading. The results suggest that the reinforcement effect was achieved due to strong hydrogen bonding or polar–polar interactions between NBR matrix and BT filler. This is further corroborated by the good dispersion of BT filler in the NBR matrix observed with SEM imaging. These findings can be applied to produce high‐performance dielectric elastomers. © 2020 Society of Industrial Chemistry     

丙烯腈装置回收塔内聚合物生成原因的分析

针对丙烯腈生产过程中回收塔内聚合物堵塞降液管造成回收塔运行周期短的问题,通过对丙烯腈回收塔内各组分分布的模拟计算,直观显示了回收塔内各组分的浓度分布,发现了回收塔的聚合段与丙烯醛的富集段相吻合的现象,初步得出了回收塔内局部聚合的原因;通过对塔内聚合物的特性分析和评判,进一步证实了“回收塔内局部聚合严重是由于在聚合段丙烯醛聚集引起”这一现象;根据模拟计算结果和实际运行经验,提出了预防聚合物堵塞降液管的措施,并进行了部分生产验证,为丙烯腈生产企业延长装置运行周期提供了理论指导。     

N-苄基丙烯酰胺的合成

以丙烯腈和苯甲醇为原料，浓硫酸作催化剂，合成了N-苄基丙烯酰胺（N-BAA）。考察了反应温度、反应时间和催化剂用量等因素对产物收率的影响，得出了最佳反应条件：n（丙烯腈）：n（苯甲醇）：n（浓硫酸）=3：1：1．2，反应时间3h，反应温度60℃。在最佳条件下，N-BAA的收率可达92％。每100g粗产物用10％氢氧化钠溶液提纯，精制产物纯度可达99．80％，熔点为64～65℃。通过红外光谱对产物结构进行了表征。     

A new polymer electrolyte poly(acrylonitrile)-dimethylsulphoxide-salt for electrochemical capacitors

The PAN-DMSO-Et₄NBF₄ and PAN-DMSO-Et₄NTf (Tf is triflate ion) electrolytes were prepared as white, turbid foils with a thickness in the range of 0.1-0.5 mm, using the casting technique. Room temperature conductance of the electrolytes, detected from ac impedance experiments, was at the level of 8 and 14 mS cm⁻¹ for Et₄NBF₄ and Et₄NTf salts, respectively. The electrochemical stability window of approximately 2.6-2.8 V was estimated using a glassy carbon electrode. Temperature dependence of the conductivity is of the Arrhenius-type for both electrolytes, with an activation energy of approximately 34 kJ mol⁻¹. The double-layer capacitors built with these electrolytes, serving both as separators and activated carbon powder (ACP) binders, showed a specific capacity of 50 F g⁻¹ of carbon material. Capacitors were assembled by sandwiching the PAN-DMSO-salt electrolyte between two PAN-salt-DMSO-ACP-AB electrodes and pressing across the system; the resulting devices had a coin-like shape with 8 mm diameter and thickness between 2.0 and 2.5 mm.     

Complex formation of montmorillonite clay with polymers. Part 2: The use of montmorillonite clay–vinyl monomer complex as a comonomer in the copolymerization reaction of styrene–acrylonitrile monomers

The bulk copolymerization of styrene–acrylonitrile monomers using styrene‐N⁺–montmorillonite complex as a comonomer in the polymerization was studied. The X‐ray diffraction (XRD) analysis showed that part of the styrene‐N⁺–montmorillonite complex remained non‐dispersed (immiscible) and the copolymer was excluded from the interlayer of the immiscible part of the clay. The successive chemical extraction process revealed that a reasonable amount of the styrene–acrylonitrile copolymer was directly attached to the styrene‐N⁺–montmorillonite complex and enveloped the clay. Highly exfoliated clay lamella and nanospheres (3–5 nm) were observed by transmission electron microscopy (TEM). The montmorillonite clay assume two different morphologies, immiscible and exfoliated, on the basis of the XRD and TEM data. A simple method of calculation of the ratio of the exfoliated/immiscible amounts of the clay indicated that the amount of the styrene‐N⁺–montmorillonite complex exfoliated into separate lamella was 40 % (w/w) of the amount of the clay samples containing 2 % of the (styrene‐N⁺–montmorillonite complex) clay. This amount of exfoliated clay decreases with the increase of the concentration of the clay. The presence of the styrene‐N⁺–montmorillonite clay in the copolymerization reaction had a minor effect on both the copolymer composition and the molecular weight. Modification of the clay with the derivatized styrene monomer can achieve a nanocomposite using a percentage no more than 4 % (w/w) of complex in the copolymer. Copyright © 2004 Society of Chemical Industry     

中国丙烯腈生产技术国产化发展过程

论述了30年来中国丙烯腈生产技术的发展概况和目前达到的技术水平。中国于1960年开始氨氧化法制丙烯腈技术的开发,大致可分为三个时期:1960—1969年实验室基础研究和中间试验,进行了固定床和流化床及相适应的催化剂以及丙烯腈回收精制工艺的研究。1970—1980年建成了一批生产装置并进一步改善了生产工艺和催化剂。1981年到目前是以国际先进水平为目标,开发了高性能催化剂、流化床反应器和新的丙烯腈回收精制工艺。目前已开发成功的MB-86型催化剂、内构件流化床、复合萃取分离新工艺等具有国际80年代末期水平。丙烯单耗为1.02—1.05t丙烯/t丙烯腈,同时可分离出纤维级丙烯腈,高纯度氢氰酸和浓度达80%的乙腈。也完成了乙腈精制、硫铵回收等副产物回收技术。在此基础上已经开始设计两个万吨级丙烯腈工厂。     

丙烯腈急冷塔喷淋系统流道分析与优化

对国内现有丙烯腈装置急冷塔循环液喷淋器的分流流道进行了研究。对喷头堵塞情况作了理论分析，并运用计算机编程模拟计算出喷淋器中各喷头的流体分布情况。在此基础上提出了分流流道的优化方案，从而改善了急冷塔内的操作状况，减少了丙烯腈在急冷塔内的损失。     

Functional copolymer of geraniol and acrylonitrile: Synthesis and characterization

The radical copolymerization of acyclic terpene namely geraniol [GER] with acrylonitrile [AN] in DMF at (70 ± 0.1)°C for 1 h, using benzoylperoxide (BPO) as an initiator has been carried out under inert atmosphere of nitrogen. The kinetic expression for reaction is R_p ∝ [BPO]^0.5 [AN]^1.0 [GER]^1.0. The IR spectrum of the copolymer shows bands at 3432 and at 2244 cm^?1 due to ? OH group of GER and ? CN group of AN, respectively. The ¹³C‐NMR spectrum shows peaks at 73–75 δ ppm and 116–120 δ ppm due to ? OH group of GER and ? CN group of AN, respectively. The thermogravimetric analysis and differential scanning calorimetry study shows that copolymer is thermally stable up to 407°C and has glass transition temperatures (T_g) 56°C. The reactivity ratios r₁ (AN) and r₂ (GER) have been calculated as 0.05 and 0.005, respectively. The Alfrey‐Price Q‐e parameter for GER has been calculated as 0.094 and ?2.0, respectively. The molecular weights of the copolymers have been evaluated by gel‐permeation chromatography. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Radiation polymerization of acrylonitrile in a viscous system with styrene

Radiation polymerization of acrylonitrile in a viscous system with styrene was performed at ambient temperature by using γ‐rays. It is found that the overall rate of polymerization was accelerated after critical conversion due to the gel effect. As the molar fraction of styrene in monomer feed (f_St) is increased, both the total polymer conversion and molar fraction of acrylonitrile in the copolymer feed (F_AN) were decreased. The monomer reactivity ratios for acrylonitrile and styerne were determined to be r₁ (AN) = 0.25 and r₂ (St) = 2.0, respectively. The copolymers obtained were characterized by Fourier transformed infrared spectra (FTIR), X‐ray diffraction (XRD), scanning electron microscopy (SEM), ¹H‐NMR, and pyrolysis mass spectrometry (PMS). It was found that the slight addition of styrene to acrylonitrile strongly changes crystallinity, morphology, and thermal decomposition of the resulting polymer. ¹H‐NMR measurment of AN/St copolymer showed the appearance of aromatic proton signals and shifted the resonance of the methylene proton to lower chemical shifts. The mass spectra of AN/St copolymers showed fragments of pyrolysates corresponding to oligonitriles with styrene end groups. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 268–275, 2002; DOI 10.1002/app.10324     

MB-86型丙烯腈催化剂的工业应用

MB-86丙烯腈催化剂通过大庆石化总厂化纤厂7000吨/年丙烯腈装置工业应用,丙烯腈单程收率80％以上,丙烯单耗为1.05—1.08吨/吨丙烯腈。工业运转结果表明,MB-86催化剂稳定性及耐磨性良好,反应产物分布合理。可用于原使用C_(41)、C_(49)及类似系列催化剂的万吨级丙烯腈工厂,反应器不必进行改造。