Non-phosgene synthesis of hexamethylene-1,6-diisocyanate from thermal decomposition of hexamethylene-1,6-dicarbamate over Zn–Co bimetallic supported ZSM-5 catalyst

A non-phosgene route for the synthesis of hexamethylene-1,6-diisocyanate(HDI) was developed via catalytic decomposition of hexamethylene-1,6-dicarbamate(HDC) over Zn–Co bi-metallic supported ZSM-5 catalyst.The catalyst was characterized by FTIR and XRD analyses. Three solvents dioctyl sebacate(DOS), dibutyl sebacate(DBS) and 1-butyl-3-methylimidazolium tetrafluoroborate(BMIMBF_4) were investigated and compared; DOS gave better performance. The catalytic performances for thermal decomposition of HDC to HDI using DOS as solvent were then investigated, and the results showed that, under the optimized reaction conditions, i.e.,10 wt%concentration of HDC in DOS, 250 °C temperature, 60 min reaction time, 83.8% yield of HDI had been achieved over Zn–Co/ZSM-5. Decomposition of the intermediate hexamethylene-1-carbamate-6-isocyanate(HMI) over Zn–Co/ZSM-5 in DOS solvent was further studied and the results indicated that yield of HDI from HMI reached to 69.6%(98.6% HDI selectively) at 270 °C, which further increased the yield of the total HDI(HDI_(tol)) to as high as 95.0%. Recycling of catalyst showed that HDI and HMI yield slightly decreased, and by-product yield increased after the catalyst was reused for 4 times. At last possible reaction mechanism was proposed.

An efficient green route for hexamethylene-1,6-diisocyanate synthesis by thermal decomposition of hexamethylene-1,6-dicarbamate over Co3O4/ZSM-5 catalyst： An indirect utilization of CO2

The utilization of CO2 as raw material for chemical synthesis has the potential for substantial economic and green benefits. Thermal decomposition of hexamethylene-1,6-dicarbamate （HDC） is a promising approach for indirect utilization of CO2 to produce hexamethylene-1,6-diisocyanate （HDI）. In this work, a green route was developed for the synthesis of HD1 by thermal decomposition of HDC over Co3O4/ZSM-5 catalyst, using chlorobenzene as low boiling point solvent. Different metal oxide supported catalysts were prepared by incipient wetness impregnation （IWI）, PEG-additive （PEG） and deposition precipitation with ammonia evaporation （DP） methods. Their catalytic performances for the thermal decomposition of HDC were tested. The catalyst screening results showed that Co3O4/ZSM-525 catalysts prepared by different methods showed different performances in the order of Co3O4/ZSM-5 25（PEG） 〉 Co3O4/ZSM-525（IWI） 〉 Co3O4/ZSM-525（DP）. The physicochemical properties of Co3O4/ZSM- 52s catalyst were characterized by XRD, FTIR, N2 adsorption-desorption measurements, NH3-TPD and XPS. The superior catalytic performance of Co3O4/ZSM-52S（PEG） catalyst was attributed to its relative surface content of Co3 ＋, surface lattice oxygen content and total acidity. Under the optimized reaction conditions： 6.5% HDC concentration in chlorobenzene, 1 wt% Co3O4/ZSM-525（PEG） catalyst, 250℃ temperature, 2.5 h time, 800 ml.min 1 nitrogen flow rate and 1.0 MPa pressure, the HDC conversion and HDI yield could reach 100% and 92.8% respectively. The Co3O4/ZSM-525（PEG） catalyst could be facilely separated from the reaction mixture, and reused without degradation in catalytic performance. Furthermore, a possible reaction mechanism was proposed based on the physicochemical properties of the Co3O4/ZSM-5 25 catalysts.

The Curing for Modified Vinyl Ester Resin by Hexamethylene Diisocyanate and Its Influence on Performances

The commercial vinyl ester resins(VER)was modified by diphenylmethane diisocyanate(MDI)to enhance its toughness,which is called MVER.Hexamethylene diisocyanate(HDI),a common curing agent for polyurethane(PU),was found to be a reactive agent for MVER and can contribute to the toughness of MVER.Based on present experiment results,the crosslinking mechanism of MVER and HDI system is very similar to that of PU.The FTIR result shows the-NCO of HDI can react with the-OH of MVER.The microstructure of material prepared by MVER and HDI was characterized by NMR,and it was revealed that the unique microstructure leads to the good performances.The different content of HDI has an influence on the microstructure,and the microstructure gradually reduces the toughness and mechanical performances of the MVER cured with increasing concentration of reactive curing agent(HDI).This feature is consistent with a maximum in toughness as a function of the additive(HDI)content,followed by a rapid deterioration in toughness at higher concentrations.The toughness exhibits the maximum at such an HDI concentration(20wt%).Therefore,the special curing agent(HDI)and reactive mode is very important to the microstructure and mechanical properties of material.Furthermore,there should be other reactions which contribute to the curing and microstructure of the material,which needs the further research.

CAHB诱导成人急性淋巴细胞白血病Jurkat细胞凋亡机制的研究

目的 探讨二乙酰己二胺(diacetyl hexamethylene diamine,CAHB)诱导成人急性淋巴细胞白血病Jurkat细胞凋亡的机制,为CAHB应用于临床提供理论依据。方法 采用流式细胞仪分析CAHB处理后Jurkat细胞AnnexinⅤ^(+)/PI^(-)细胞率,观察应用胱天蛋白酶(caspase)-9抑制剂Z-LEHD-FMK处理后AnnexinⅤ^(+)/PI^(-)细胞率的变化;蛋白质印迹法观察凋亡相关蛋白caspase-8、caspase-9、caspase-3的表达变化。结果 CAHB诱导后Jurkat细胞体积缩小、胞膜皱缩、染色质浓染、核固缩或碎裂等,可见典型凋亡小体。CAHB通过激活caspase-9、caspase-3诱导Jurkat细胞发生凋亡,其作用呈明显的量效关系和时间依赖性,caspase-9抑制剂可在一定程度上抑制CAHB的凋亡诱导作用。结论 CAHB诱导Jurkat细胞凋亡与激活caspase-9及caspase-3有关。

六亚甲基二异氰酸酯与丙烯酸羟乙酯反应动力学及热动力学研究

研究了六亚甲基二异氰酸酯(HDI)与丙烯酸羟乙酯(HEA)在聚氨酯合成反应中的动力学和热动力学特征。在反应动力学方面,采用甲苯-二正丁胺滴定法获取了反应转化率数据,分别构建了二级动力学模型和Sato动力学模型来拟合实验数据。结果表明:该反应符合Van't Hoff近似规则;低转化率时,二级动力学模型拟合效果较好;而在高转化率时,由于存在自催化作用,Sato动力学模型具有更好的拟合优势;在热动力学方面,使用绝热加速量热仪(ARC)对反应放热进行了表征分析,结果显示该反应的热动力学反应级数为0.8,表观活化能为57.51 kJ/mol。该研究为聚氨酯的安全、高效和绿色合成提供了科学理论依据。

抗硫化返原剂二水合六亚甲基-1,6-二硫代硫酸二钠的制备

使用1,6-二氯己烷与五水合硫代硫酸钠合成出抗硫化返原剂二水合六亚甲基-1,6-二硫代硫酸二钠,通过正交试验和单因素实验考察其粗产品的合成工艺条件;对获得的产品进行重结晶纯化,结合硫代硫酸钠在乙醇-水溶液体系中不同温度的溶解度获得重结晶过程中溶剂的最优乙醇浓度、重结晶温度和结晶次数;最后对所合成产品进行了傅里叶变换红外光谱、X射线衍射及热重-差示扫描量热法的分析。结果表明,合成二水合六亚甲基-1,6-二硫代硫酸二钠的最佳反应条件为1,6-二氯己烷质量分数14%、乙醇与水的质量比3/4、反应体系pH值9、反应温度83℃,此时所合成粗产品的纯度和收率最高;使用质量分数为80%的乙醇溶液在20℃下重结晶精制2次,可制得纯度达97%以上、单程收率在80%以上的产品。

Preparation of Environmentally Friendly Urea-Hexanediamine-Glyoxal(HUG)Resin Wood Adhesive

Using non-toxic,low-volatile glyoxal to completely replace formaldehyde for preparing urea-glyoxal(UG)resin adhesive is a hot research topic that could be of great interest for the wood industry.However,urea-glyoxal(UG)resins prepared by just using glyoxal instead of formaldehyde usually yields a lower degree of polymerization.This results in a poorer bonding performance and water resistance of UG resins.A good solution is to pre-react urea to preform polyurea molecules presenting already a certain degree of polymerization,and then to condense these with glyoxal to obtain a novel UG resin.Therefore,in this present work,the urea was reacted with hexamethylene diamine to form a polyurea named HU,and then this was used to react it with different amounts of glyoxal to synthesize hexamethylenediamine-urea-glyoxal(HUG)polycondensation resins,and to use this for bonding plywood.The results show that the glyoxal can well react with HU polyuria via addition and schiff base reaction,and also the HUG resin exhibits excellent bonding strength and water resistance.The shear strength of the plywood bonded with this HUG at 160°C hot press temperature as high as 1.93 MPa,2.16 MPa and 1.61 MPa,respectively,which meets the requirement of the China national standard GB/T 9846-2015(≥0.7 MPa),and can be a good choice as a wood adhesive for industrial application.

单体中仲胺类化合物含量对长碳链尼龙1012性能的影响

以癸二胺和十二碳二元酸为原料制备尼龙1012盐,然后将双六甲基三胺作为含仲胺结构的化合物引入到尼龙1012盐聚合反应中制备尼龙1012,考察双六甲基三胺含量对尼龙1012性能的影响。结果表明:随着双六甲基三胺含量的增加,尼龙1012的相对分子质量逐渐增大,相对分子质量分布明显变宽,双六甲基三胺质量分数从0增加至2.0%,聚合物分散性指数从2.48上升到4.29;当双六甲基三胺质量分数大于1.0%时,尼龙1012的动态流变性能表现出弹性大于黏性的行为;随着双六甲基三胺含量的增加,尼龙1012的熔融温度和结晶温度均呈现逐渐降低趋势,而热分解温度逐渐上升;双六甲基三胺质量分数从0增加至1.0%,尼龙1012的拉伸强度逐渐降低,缺口冲击强度逐渐增大;双六甲基三胺的仲胺结构参与了聚合反应,形成了支化、交联结构,交联结构的增加有利于提高尼龙1012的拉伸强度。

胍基化壳聚糖季铵盐的制备及其抗菌性能

以三聚氯氰(TCT)为中间桥梁,将聚六亚甲基双胍(PHMB)接枝到N-(2-羟丙基-3-甲基氯化铵)壳聚糖(HTCC)上,制备胍基壳聚糖季铵盐(HCP).研究制备HCP的最佳反应条件,采用元素分析、傅里叶变换红外光谱(FTIR)和核磁共振氢谱(^(1)H NMR)对产物的结构进行表征,并测试其抗菌性能.得到HCP的最佳反应条件为HTCC和TCT的摩尔比1.0∶2.5,HTCC和PHMB的质量比1.0∶1.2,缚酸剂为三乙胺,TCT一取代的反应时间8 h,二取代的反应时间14 h,反应温度40℃.结果表明:制得的HCP对大肠杆菌(E.coli)和金黄色葡萄球菌(S.aureus)的最低抑菌质量浓度分别为0.020,0.005 mg·mL^(-1);质量浓度为1.0 mg·mL^(-1)的HCP对E.coli和S.aureus的抑菌率分别为89.8%和100.0%,高于相同质量浓度下HTCC对E.coli和S.aureus的抑菌率18.2%和18.7%.

六亚甲基二异氰酸酯微胶囊的制备及其在自修复涂料中的应用

目的制备一种基于小尺寸六亚甲基二异氰酸酯(HDI)微胶囊的自修复防腐涂料,能够提高涂层的防腐性能并实现涂层划痕缺陷的在线修复。方法通过调整界面聚合法合成HDI微胶囊过程中的乳化剂添加量、搅拌速率和体系pH值,降低微胶囊的平均粒径,并利用囊芯染色试验、红外光谱(FTIR)、热重试验(TG)对微胶囊的结构和热稳定性进行表征。以物理共混的方式将微胶囊掺入到环氧树脂基质中制备自修复防腐涂料,使用万能拉伸机、拉拔测试仪、电化学阻抗谱(EIS)研究微胶囊对涂层基础力学性能和耐腐蚀性能的影响。结合丝束电极(WBE)测试与划痕涂层浸泡腐蚀试验分析复合涂层的内在自修复机理。结果确定了微胶囊制备过程的最佳乳化剂添加量为3%、搅拌速率为600 r/min、体系pH值为3.5,此时的微胶囊呈规则的球状结构,表面致密且具有一定的粗糙度,平均粒径尺寸降低为59μm,成型率达82%。FTIR和囊芯染色试验证明微胶囊由脲醛树脂囊壁和HDI囊芯组成,TG分析显示微胶囊初始分解温度为260℃。随着微胶囊含量的提高,自修复涂层的拉伸断裂强度和附着力有所下降。EIS测试结果表明,含0%、1%、5%和10%微胶囊的自修复涂层经3.5%NaCl溶液浸泡144 h后,涂层电阻(Rc)分别为1.5×10^(8)、2.2×10^(8)、3.7×10^(8)、2.8×10^(8)Ω/cm^(2)。WBE和浸泡腐蚀试验显示,5%微胶囊掺入量的复合涂层具有最佳的划痕自修复性能,32 h浸泡后的涂层愈合效果良好。结论当采用界面聚合法制备的HDI微胶囊均匀分散至涂层内部,可以协同提高涂层的耐腐蚀性能。此外,微胶囊能够在涂层划痕损伤位置主动释放囊芯HDI,与腐蚀溶液反应生成聚氨酯类物质填补涂层的裂纹缺陷,产生局部自愈合效果。

二水合六亚甲基-1,6-二硫代硫酸二钠盐对天然橡胶-镀铜钢丝黏合性能的影响

研究了二水合六亚甲基-1,6-二硫代硫酸二钠盐(HTS)用量对天然橡胶(NR)-镀铜钢丝黏合胶料硫化性能、力学性能黏合性能的影响。结果表明,HTS的加入减少了胶料的焦烧时间,随着HTS用量增加,硫化胶的表观交联密度呈现先上升后下降的趋势,力学性能也表现出相近的变化规律;HTS可以改善NR-镀铜钢丝黏合界面强度及橡胶本体强度,当HTS的用量为2份时,黏合性能最佳。

清洁合成1,6-六亚甲基二异氰酸酯

利用1,6-六亚甲基二氨基甲酸正丁酯(HDU-B)热分解反应清洁合成了1,6-六亚甲基二异氰酸酯(HDI)。通过对HDU-B热分解反应机理的分析和反复实验,自行设计了热分解反应装置,并利用此装置考察了在一定的压力下,反应温度、作为热载体的惰性高沸点溶剂、催化剂等对HDU-B热分解反应的影响。实验结果表明,最佳惰性高沸点溶剂为环烷油,适宜的催化剂有锌、铝和氧化锌及它们之间组合的双组分催化剂。实验还发现,具有弱酸性的Lewis酸金属氧化物和锌对HDU-B热分解反应具有一定的正协同作用。最佳反应条件为:采用锌和氧化锌双组分催化剂,反应温度250℃,真空度0.094MPa,反应时间15min。在此条件下,HDI的收率为81.24%。

高分子保护沉淀法制备超细纳米氧化镁

The precursor for nano-sized magnesia was prepared by using Mg(NO3)2·6H2O as raw material, the hydrolysis product of hexamethylene tetramine as precipitating reagent and water as reaction media, and with the polymer (PEG) and DMF as protection reagents for particles. Nano-sized magnesia was prepared by calcining the precursor at 873 K after being dehydrated by freeze centrifugation and vacuum drying at a constant temperature. The formation process and structure of MgO nanocrystallites were investigated by means of TG-DTA, FTIR, TEM, XRD and BET. The results showed that the crystal belonged to cubic system and the average size was 3.1 nm and the specific surface area was 229 m2·g-1.

以尿素为羰化剂合成六亚甲基二氨基甲酸酯的工艺研究

对尿素作为羰基化试剂合成六亚甲基二氨基甲酸酯进行了可行性研究,用正交实验法确定了合成反应的较佳工艺条件:温度225℃,反应时间5 h,催化剂用量、尿素用量与己二胺的物质的量比为0.000 5∶2.5∶1。分析讨论了反应温度、反应时间、催化剂用量等工艺条件对产物收率的影响,发现催化剂最佳用量为己二胺的0.1%(物质的量分数),并验证副产物是完全可以回用的。

静电纺纳米级纤维复合膜及其过滤性能

采用1，2-二氯乙烷和三氟乙酸共混物为溶剂（质量比2：1），在室温下配制了质量分数为13％的聚己二酸己二醇酯纺丝液，通过静电纺制备了直径范围在80～500nm之间的聚己二酸己二醇酯纳米级纤维和驻极体熔喷非织造布与纳米级纤维复合膜，借助扫描电子显微镜观察了纳米级纤维表面形貌结构，此外还探讨了驻极体熔喷非织造布与纳米级纤维复合膜的过滤性能。结果表明，在气流速度为2．83L／min时，该复合膜对粒径为0．3脚粉尘的过滤效率高达99．9％。

木素型聚氨酯的合成与性能研究

利用木素和两种二异氰酸酯合成了聚氨酯 ,对其热性能、力学性能、膨胀性能进行了测试。结果表明 ,羟丙基化改性将木素变为聚酯 -醚多元醇 ,可与二异氰酸酯合成木素聚氨酯 ;异氰酸酯基与羟基配比对用TDI与HDI合成的聚氨酯性能影响不同。

低沸点溶剂加压催化热解制备六亚甲基-1，6-二异氰酸酯

以低沸点氯苯为溶剂,在加压条件下进行了六亚甲基-1,6-二氨基甲酸甲酯(HDC)液相催化热解制备六亚甲基-1,6-二异氰酸酯(HDI)的研究;通过TG-DTG技术对HDC热解过程进行了分析,筛选了催化剂,优化了工艺条件,并通过原位FTIR技术推测了HDC的催化热解机理。实验结果表明,HDC热解制备HDI分两步完成;优化的反应条件为:采用Co2O3催化剂、反应温度230℃、HDC含量为溶剂质量的2.5%、催化剂用量为HDC质量的5%、N2流量为600 mL/min、反应时间3 h,在此条件下,HDC的转化率可达100%、HDI收率可达83%左右。机理研究推测:Co2O3催化剂是通过进攻HDC的氨基甲酸甲酯基团上的C=O双键,最终使酯基断裂形成异氰酸根基团。

双亲性氧化石墨烯的合成及生物相容性

以六亚甲基二异氰酸酯(HMDI)为偶联剂,通过与氧化石墨烯(GO)中的羧基或羟基反应,形成酰胺键或氨基甲酸酯键活化GO,然后与TWEEN 80中的羟基反应,将双亲性TWEEN分子偶联于GO表面,制备了双亲性GO.所制备的TWEEN 80接枝GO在水、氯仿和己烷等溶剂中均可稳定分散.以PC12及HeLa细胞为细胞模型,考察TWEEN 80接枝GO所制薄膜的细胞毒性,形态学观察及细胞活性检测(Calcein AM&EthD-1荧光染色及MTT检测)结果表明其具有良好的生物相容性.

中药白龙与HMBA对人癌周期细胞CKI-P16的调控

目的 :研究中药白龙与西药环六亚甲基二乙酰胺 (HMBA)对人癌细胞中周期蛋白抑制因子P16的表达与调节。方法 :采用Northernblot、Westernblot等方法检测人癌细胞在白龙或HMBA作用下P16的表达调节。结果 :在白龙或HMBA作用下癌细胞G1期P16的表达增加 ,这一作用与cAMP PKA和DAC PKC两套信号通路共调节作用密切相关。当以PKA抑制剂阻断PKA通路时 ,P16表达下降 ,相反当PKC通路被阻断时P16表达水平升高。结论 :(1)癌细胞G1期P16的低表达 (与其他时相比较 )可能是P16不能有效抑制癌细胞恶性变化的重要原因。 (2 )白龙和HMBA对肿瘤细胞的增殖抑制机理与G1期细胞P16表达升高相关。 (3)白龙和HMBA对人癌细胞内P16的表达调节表现了中西药对肿瘤细胞调节机理的共性。 (4 )首次阐明了P16上游调控与cAMP/PKC信号通路密切相关。

二胺型腰果酚基苯并嗪的合成工艺

以己二胺、多聚甲醛和腰果酚为原料合成了一种二胺型腰果酚基苯并嗪单体.使用FTIR和1 H NMR对单体进行了化学结构表征.以产品收率为指标,考察了反应时间、反应温度、溶剂种类等反应条件对反应产物收率的影响,确定较佳反应条件为:反应时间5h,反应温度105℃,溶剂为甲苯。