改性ADC发泡剂的研究进展与市场前景

作者介绍了目前传统ADC发泡剂存在的问题,重点综述了改性ADC发泡剂产品的研究进展,包括合成工艺的改进及添加促进剂对ADC发泡剂性能的改进;同时分析了ADC发泡剂的市场情况,并对其前景进行了展望.     

浅谈ADC发泡剂生产工艺现状及改进标准

ADC发泡剂的性能较好,具有较大的发气量,因此应用十分广泛。在工业生产中应用于聚氯乙烯、聚乙烯等聚合物和塑料制品的生产中,用作橡胶的合成材料。本文主要对ADC发泡剂的生产工艺现状和改进标准进行了研究,首先对ADC发泡剂进行了简单地介绍;然后阐述了ADC发泡剂生产工艺的现状;最后提出了ADC发泡剂生产工艺的改进标准。提出采用氯化氢法来替代传统的尿素法和硫酸法来生产联二脲,这样能够获得更高纯度的联二脲产品,同时减少生产设备的腐蚀和污水排放。希望本文的研究能够优化我国ADC发泡剂的生产工艺,促进ADC发泡剂的生产。     

行业动态

工信部拟推广ADC发泡剂清洁技术为提高行业清洁生产水平,工信部组织编制了ADC发泡剂行业清洁生产技术推行方案征求意见稿,目前正在全行业公开征求意见。征求意见稿提出了ADC发泡剂行业推行清洁生产技     

ADC发泡剂的改性及其研究概况

本文根据ADC发泡剂添加活化剂的实验和研究,提出了改性ADC发泡剂可以分为无沉析型、低温型、分散型和开孔型四大系列,并介绍了国内外有关改性ADC发泡剂的研究概况。     

含锌化合物对ADC发泡剂热解的影响规律

选用不同种类含锌化合物对ADC发泡剂的分解温度、分解速率、发气量等热解因素的影响进行了规律性研究。采用DSC测定ADC发泡剂热效应及含锌化合物对其分解热焓的影响。最后筛选出满足EVA加工条件的改性ADC发泡剂,对其模压发泡进行力学特性及泡孔结构分析。研究表明:含锌化合物对ADC发泡剂的活化作用是一种催化作用,并且通过Lewis酸碱理论分析了活化程度的不同,其中醋酸锌对ADC发泡剂的活化程度最为明显,但是氧化锌改性后的ADC发泡剂加入到EVA基体中的制得的泡沫材料的力学性能和泡孔结构更优异。     

工信部拟推广ADC发泡剂清洁技术

为提高行业清洁生产水平，工信部组织编制了ADC发泡剂行业清洁生产技术推行方案征求意见稿．目前正在全行业公开征求意见。征求意见稿提出了ADC发泡剂行业推行清洁生产技术的总体目标：到2015年，完成酮连氮法水合肼生产ADC发泡剂技术的工业化应用示范，ADC发泡剂缩合母液资源化利用技术普及率达40％。以2015年预计ADC发泡剂产量200kt计．将减少高含盐、高浓度氨氮废水产生量600kt／a．同时减少氨氮产生量47kt／a。     

发泡剂ADC改性的研究现状和发展趋势

系统地概述了近几十年来国内外对发泡剂ADC进行改性的研究状况,并探讨了未来发泡剂ADC改性研究的发展趋势.     

PVC-U低发泡制品中常用发泡剂性能分析

介绍了PVC-U低发泡制品中常用的发泡剂及其发展趋势,分析了不同发泡剂对生产加工及制品性能的影响。结果表明,NaHCO3发泡剂和ADC发泡剂复合使用,可以使热量的吸热、放热互补,形成平衡,发泡易于控制;ADC发泡剂的粒径越细,产品发泡越均匀、细密,密度越小,材料性能越好;当熔体强度适宜时,ADC发泡剂添加量越多,在熔体中形成的气泡也越多,制品的密度越小。     

1万t/a发泡剂ADC装置工艺设计

发泡剂ADC是当今世界上使用量最大的橡胶和塑料发泡剂,目前国内主要的生产厂家都有继续扩产的计划,笔者仅以1万t/a发泡剂ADC为例,简要地介绍了发泡剂ADC装置的工艺流程、主要设备选型与台数计算、设计中应注意的问题以及三废回收治理措施,在获得经济效益的同时也获得了社会效益.     

1万t／a发泡剂ADC装置工艺设计

发泡剂ADC是当今世界上使用量最大的橡胶和塑料发泡剂,目前国内主要的生产厂家都有继续扩产的计划,笔者仅以1万t/a发泡剂ADC为例,简要地介绍了发泡剂ADC装置的工艺流程,主要设备选型与台数计算,设计中应注意的问题以及三废回收治理措施,在获得经济效益的同时也获得了社会效益。     

ADC干燥系统预防分解的改进措施

介绍了对ADC干燥系统的生产工艺和操作方面的改进。通过改进，减少了ADC分解事故的发生．提高了ADC干燥生产的安全性。     

基于热失重分析对聚合物发泡剂ADC发气量测定方法的研究

根据偶氮二甲酰胺(ADC)热分解第一阶段(200～240℃)的分解方程式,建立ADC的分解过程与发气过程之间的函数关系式,将ADC的热失重(TG)曲线转变为TG发气曲线.结果表明,通过对比发泡剂ADC的TG发气曲线和排水集气法测定的发气曲线,得出两种测定方法测得ADC的起发温度、最大发气速率温度、终止发气温度等数据非常...     

Stereocontrolled Synthesis and Pharmacological Evaluation of Azetidine‐2,3‐Dicarboxylic Acids at NMDA Receptors

The four stereoisomers of azetidine‐2,3‐dicaroxylic acid (L ‐trans‐ADC, L ‐cis‐ADC, D ‐trans‐ADC, and D ‐cis‐ADC) were synthesized in a stereocontrolled fashion following two distinct strategies: one providing the two cis‐ADC enantiomers and one giving access to the two trans‐ADC enantiomers. The four azetidinic amino acids were characterized in a radioligand binding assay ([³H]CGP39653) at native NMDA receptors: L ‐trans‐ADC showed the highest affinity (K_i=10 μM ) followed by the D ‐cis‐ADC stereoisomer (21 μM ). In contrast, the two analogues L ‐cis‐ADC and D ‐trans‐ADC were low‐affinity ligands (>100 and 90 μM , respectively). Electrophysiological characterization of the ADC compounds at the four NMDA receptor subtypes NR1/NR2A, NR1/NR2B, NR1/NR2C, and NR1/NR2D expressed in Xenopus oocytes showed that L ‐trans‐ADC displayed the highest agonist potency at NR1/NR2D (EC₅₀=50 μM ), which was 9.4‐, 3.4‐, and 1.9‐fold higher than the respective potencies at NR1/NR2A–C. D ‐cis‐ADC was shown to be a partial agonist at NR1/NR2C and NR1/NR2D with medium‐range micromolar potencies (EC₅₀=720 and 230 μM , respectively). A subsequent in silico ligand–protein docking study suggested an unusual binding mode for these amino acids in the agonist binding site.     

Burning Characteristics of Ammonium Nitrate‐based Composite Propellants Supplemented with Ammonium Dichromate

Ammonium nitrate (AN)‐based composite propellants have attracted much attention, primarily because of the clean burning nature of AN as an oxidizer. However, such propellants have some disadvantages such as poor ignition and low burning rate. Ammonium dichromate (ADC) is used as a burning catalyst for AN‐based propellants; however, the effect of ADC on the burning characteristics has yet to be sufficiently delineated. The burning characteristics of AN/ADC propellants prepared with various contents of AN and ADC have been investigated in this study. The theoretical performance of an AN‐based propellant is improved by the addition of ADC. The increase in the burning rate is enhanced and the pressure deflagration limit (PDL) becomes lower with increasing amount of ADC added. The increasing ratio of the burning rate with respect to the amount of ADC is independent of the AN content and the combustion pressure. The optimal amount of ADC for improving the burning characteristics has been determined.     

PE管过滤器在ADC发泡剂生产中的应用

介绍了PE管过滤器的结构、原理。在ADC发泡剂生产过程中利用PE管过滤器,可有效回收生产废水中的联二脲和ADC发泡剂,既创造了经济效益,又减轻了环保处理压力。     

Mechanical Behavior and Biodegradation of Poly(ε-caprolactone)/Starch Blends with and without Expansor

Summary The use of biodegradable polymers has provided an alternative to the problem of polymer-based products discarded in the environment. Poly(ε-caprolactone) (PCL) is a biodegradable polymer that has been used industrially, but it is very expensive. Starch is a potentially useful material for biodegradable plastics because of its natural abundance and low cost. The aim of this work was to examine the effect of adding azodicarbonomide (ADC) as an expansor to blends of PCL with corn starch. Different proportions, of ADC (0.1%, 0.2% and 0.3%, w/w) were added to pure PCL and to PCL/starch (50/50) blends and their properties were studied. Biodegradable blends of PCL with starch had a higher density than PCL alone and the addition of ADC reduced the density of the materials. The incorporation of starch increased the water absorption and ADC did not significantly alter this property. The incorporation of starch into PCL reduced the tensile strength and the elongation at break; ADC enhanced these reductions and also decreased the Young’s modulus of PCL. SEM showed that blends prepared with starch were immiscible, had a homogeneous dispersion of starch, and poor interfacial adhesion. The addition of ADC resulted in cells in the interior of the polymers. The 50/50 PCL/starch blends biodegraded faster than PCL, and ADC had no significant influence on the biodegradation of the blends but inhibited the biodegradation of PCL.     

Morphology and mechanical properties of interpenetrating polymer networks of poly(allyl diglycol carbonate) and rigid polyurethane

Novel simultaneous interpenetrating polymer networks (SINs) of poly(allyl diglycol carbonate) (ADC) and a rigid high modulus polyurethane based on the Conathane UC‐33 prepolymer system (UC) were synthesized. The completion of each component reaction was verified by means of Fourier transform IR spectroscopy. The effects of the composition on the morphology, mechanical properties, and thermal transition behavior of the SINs were studied. At 10% composition, transmission electron microscopy revealed complete phase miscibility. This was also supported by the high optical transparency of the sample. As the UC content increased to 20% a two‐phase morphology was observed in which the UC phase domains were dispersed in the matrix of the ADC phase. At higher UC content the ADC continuous phase was replaced by the UC phase, implying the occurrence of phase inversion. This variation of morphology allowed the SINs to have a property range from the UC‐toughened plastics to the ADC‐reinforced polyurethane. The SINs containing 50% UC showed synergism in the mechanical properties as the elongation was significantly increased to 4 times that of the unmodified UC and ADC homopolymers. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 3361–3370, 2001     

ADC生产中缩合废水的综合利用和治理

ADC发泡剂生产过程中的缩合废水治理问题是目前制约ADC行业生存和发展的关键问题之一,是国内外同行业关注的焦点.本文介绍通过回收缩合废水中有回收价值的物质,同时达到废水综合治理的目的.