Interaction between medetomidine and alkyd resins: NMR and FTIR investigation of antifouling marine paint model systems

The synthesis and optimization of novel bioactive components is key to the development of antifouling marine coatings. It was recently demonstrated that medetomidine (MM) has perfect antibarnacle behavior along with good ecological properties. To investigate the applicability of MM in self‐polishing marine paints, a large set of mixtures of MM with two commercial alkyd resins (ARs) was prepared. The nature and strength of the intermolecular interaction as a function of composition in both the liquid and solid states were studied using NMR and FTIR techniques, respectively. It was found that at low concentrations MM molecules were coordinated to alkyd resin chains by hydrogen bonding. This interaction had a multidentate character (i.e., one molecule of MM interacted with several ? COOH species of ARs) that resulted in stronger bonding between the two compounds. However, at higher MM concentrations an ionic association between the two compounds began, which at a large MM content resulted in microphase separation. It was noted that the strong interaction between medetomidine and the alkyd resins investigated was a positive factor for the application of these compounds in self‐polishing marine paints. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 2006     

Blends of polychloroprene and polyvinylchloride

Blends of polychloroprene rubber and plasticized polyvinylchloride have been prepared in various compositions and their properties evaluated. The properties of the blends show that they can be used to replace polychloroprene in many applications.     

铈锆复合氧化物催化HCl氧化中相互作用机制

采用浸渍法制备了不同负载量的ZrO₂/CeO₂·（xZr/Ce）和CeO₂/ZrO₂·（yCe/Zr）两组催化剂。并采用XRD、Raman、N₂-Sorption、TEM和H₂-TPR等手段对xZr/Ce和yCe/Zr的结构和性质进行表征,并结合HCl催化氧化活性研究CeO₂与ZrO₂在反应体系中的相互作用。结果显示,CeO₂表面掺杂适量的Zr⁴⁺可以增加xZr/Ce表面氧空位浓度,提高其HCl氧化反应活性;但当CeO₂表面掺杂过量的Zr⁴⁺,Zr元素会以ZrO₂的形式存在于xZr/Ce表面,覆盖氧空位,降低了xZr/Ce的反应活性。对于yCe/Zr催化剂,ZrO₂表面高分散的CeO₂有利于催化活性的提高,但ZrO₂表层负载的CeO₂对催化活性的贡献具有阈值,当CeO₂负载量超过10%后,额外增加的铈物种对催化活性已无显著促进作用;对比发现xZr/Ce的氧空位主要来自于铈锆固溶体,yCe/Zr的氧空位主要来自于高分散的CeO₂,由铈锆固溶体产生的氧空位对活性提升更有利;与纯组分CeO₂相比,xZr/Ce与yCe/Zr两组催化剂在苛刻条件下的长期稳定性测试中均表现出高反应稳定性。     

TiO2纳米管阵列粗糙度调控及其与蛋白相互作用

采用电化学阳极氧化法,通过改变电解液氟离子浓度(0.4%、0.3%、0.2%(质量))和电压(15、25、35、45 V),制备一系列不同管径和粗糙度的TiO₂纳米管阵列(TiO₂ nanotube arrays, TNAs)。通过扫描电子显微镜以及原子力显微镜(atomic force microscopy, AFM)表征,结果表明随着电解液中氟离子浓度的降低,制备得到的TNAs表面平整度更好,壁厚增大,粗糙度降低。采用AFM力学表征研究了表面粗糙度以及管径对TNAs表面力学性质以及与细胞色素C(Cytochrome C, Cyt C)相互作用的影响,结果表明,黏附力与接触面积呈正比,随着TNAs管径增加,壁厚减小,TNAs与Cyt C的有效接触面积先增大后减小,两者之间作用力也先增加后减小;同时,同管径条件下粗糙度降低,TNAs有效面积增加,相互作用力也增加;由此可见,通过改变电解液氟离子浓度可以有效调控TNAs表面粗糙度及有效接触面积,进一步利于促进与蛋白分子之间相互作用。     

Cu2+与血红蛋白相互作用的探讨

用紫外-可见光谱法和电化学方法研究了Cu^2＋与血红蛋白之间的相互作用。结果表明,Cu^2＋能与血红蛋白卟啉环上的亚铁离子发生置换反应形成铜络合物。含有高浓度Cu^2＋的溶液对血红素铁卟啉环的破坏性更强。     

Alteration of hepatic phospholipids in rats and mice by feeding di-(2-ethylhexyl)adipate and di-(2-ethylhexyl)phthalate

Effects of di-(2-ethylhexyl)adipate (DOA) and di-(2-ethylhexyl)phthalate (DEHP), plasticizers for polyvinylchloride products, on concentrations and compositions of hepatic phospholipids were studied in rats. When administered to rats at a 2% level for 2 wk, both DOA and DEHP caused a hepatomegaly, an increase in hepatic phospholipids and a decrease in the ratio of phosphatidylcholine (PC) to phosphatidylethanolamine (PE). In the comparable study with mice, the alkyl moiety of DOA was found to be responsible for these alterations. DOA and DEHP specifically altered fatty acid compositions of PC and PE: there was an increase in oleic and palmitic acids and a decrease in stearic and docosahexaenoic acids in PC and an increase in arachidonic acid at the expense of docosahexaenoic acid in PE. In addition, DOA caused an increase in the trienoic and tetraenoic molecular species in PC and an increase in the 1-palmitoyl-2-arachidonyl (16∶0//20∶4) species in PE. Thus, the effects of DOA on the lipid dynamics resembled those observed with DEHP, although the magnitude was slightly moderated.     

聚氯乙烯是家电设计的明智选择么?

家电制造商正在通过寻求低成本材料来扩大竞争优势,其不但可以提高总体经济效益,还能够保证产品的优越性能。一种已经证实可帮助家电设计师们大幅提高成本效益的聚合物材料便是硬质PVC。自1980年起,PVC已成功取代其他聚合物材料,例如:PC+ABS、阻燃ABS在家电中的应用。的确,同样的聚合物材料用于建筑领域,如窗户、房屋侧板、水管&管     

XRD法研究CaCl2与10X分子筛的相互作用

利用自发单层分散原理,通过XRD技术研究了CaCl2与10X分子筛的相互作用,讨论了温度对CaCl2分散量以及分散量对分子筛骨架结构的影响。结果表明,随着焙烧温度的升高,氯化钙的分散量增加,但焙烧温度过高,CaCl2与10X分子筛之间会发生体相反应。CaCl2的分散相与载体10X分子筛产生了相互作用,且随着CaCl2在分子筛上分散量的增加,两者之间的相互作用也增大。10X分子筛结构受到破坏程度与CaCl2的分散量之间存在正比关系。     

Correlation between network structure and brittleness of triallyl isocyanurate resins as compared with diallyl phthalate resins

It is not possible to improve the toughness of triallyl isocyanurate (TAIC) resins by applying the procedures useful for diallyl phthalate (DAP) resins as typical allyl resins. The results obtained are discussed in connection with the network structure of TAIC resin. Thus, the polymerization of TAIC would provide a homogeneous network accompanied by the incomplete occurrence of intermolecular crosslinking reactions caused by the rigidity of polymer chains, although DAP resins would consist of the microheterogeneous networks as the agglomerate of colloidal particles.     

PE树脂的流变行为与其结构性能的关系

综述了聚乙烯(PE)树脂的流变行为与其相对分子质量、相对分子质量分布、支化结构、加工性能、制品性能的关系,介绍了用流变手段及参数表征PE树脂分子结构的方法.建议加大PE树脂流变行为的研究力度,为PE树脂的产品开发与推广应用提供技术支持.     

Relationship between gelation and morphology of rubber-modified epoxy resins

The addition of both a solid and a liquid rubber to an epoxy resin has been shown to strongly increase the toughness of the material. Moreover, it is well known that toughening depends on the morphology of the system, which, in turn, depends on the cure conditions. In the present work the morphologies of epoxy resins modified with mixtures of solid and liquid rubbers have been studied through transmission electron microscopy. An investigation of the influence of the elastomers and of the gel time on the morphology of the hardened material was carried out. Gel times were evaluated, through rheological measurements, at different cure temperatures.     

白炭黑与NR的相互作用研究

研究白炭黑与NR的相互作用.结果表明,白炭黑补强NR结合橡胶中白炭黑-NR化学作用占优势;随着白炭黑表面羟基含量的增大,胶料中结合橡胶总质量分数(wBt)和化学结合橡胶质量分数(wBc)呈单调增大趋势,物理结合橡胶质量分数(wBp)变化不大;与炭黑补强NR相比,白炭黑补强NR的wBt和wBc均较大,化学结合橡胶在二甲苯中全部离解的温度高100 ℃左右,化学键强度较高;白炭黑补强NR硫化胶中化学作用占优势,对强度的贡献占主要地位,并随着白炭黑表面羟基含量的增大先减小后增大,物理作用变化趋势则相反.     

表面活性剂与聚合物的相互作用

表面活性剂与聚合物共存时，存在相互作用，体系黏度，表面张力等性能将发生变化。表面活性剂与聚合物的相互作用过程具有协同效应或非协同效应，相互作用和表面活性剂电荷、疏水性、胶束形状以及聚合物的结构、线性电荷密度和介质离子强度等因素有关，综述了表面活性剂-聚合物相互作用的研究方法、相互作用机理及表面活性剂-聚合物体系的性质和应用，着重介绍了近年来国内外的研究概况。     

Interaction between polyacrylonitrile and alkalis

Interactions between highly isotactic acrylonitrile homopolymers and alkalis in dimethyl sulfoxide solvent were examined. Coloration occurred as soon as polyacrylonitrile was added to a dimethyl sulfoxide/alkali mixture. The effects of alkali on highly isotactic polyacrylonitrile were greater than those on ordinary polyacrylonitrile. The intrinsic viscosity of polyacrylonitrile decreased quickly with the addition of sodium ethoxide and sodium hydroxide, and the effect of sodium ethoxide was more prominent than that of sodium hydroxide. As the concentration of sodium ethoxide and sodium hydroxide went beyond 0.01 mol/L, the intrinsic viscosity showed a trend of increasing. Within the first half‐hour, there was a great drop in the intrinsic viscosity of highly isotactic polyacrylonitrile, and then the intrinsic viscosity appeared to increase. The intrinsic viscosity of highly isotactic polyacrylonitrile increased continuously with the addition of diethylamine along with time. The effects of alkalis on the tacticity of the polymers followed the order of the alkali strength. Diethylamine was more effective for moderating the stabilization exotherm of polyacrylonitrile than sodium ethoxide and sodium hydroxide. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 272–275, 2006     

Interaction between Components in the KF–SiO2 System

A complex investigation of SiO₂–KF melts and products of their quenching to room temperature is performed using electrochemical measurements, quantitative X-ray diffraction analysis, and calorimetry. The structure of components in the SiO₂–KF system and the specific features in their interaction are elucidated. It is revealed that, in the composition region 0–0.33 mol % SiO₂, the interaction between the components is nearly ideal in character. The inference is made that the associates of silica and potassium fluoride can be formed in this system, and their approximate composition is determined. It is found that the associates are characterized by low enthalpies of formation. The results of analyzing the liquidus curve indicate a single eutectic and the absence of stoichiometric compounds in the system under investigation.     

Radiation chemistry of the branched-chain monoamide di-2-ethylhexyl-isobutyramide

The radiolytic degradation of di-2-ethylhexyl-isobutyramide (DEHiBA) was examined by subjecting the compound to gamma irradiation, measuring the remaining concentration of the intact compound, identifying the degradation products, and measuring uranium distribution ratios. The combined effects of radiation dose, contact with aqueous solutions of HNO₃, and aeration were also examined. The DEHiBA displayed significant stability at doses up to 1000 kGy, undergoing a slow exponential concentration decrease that was accompanied by the appearance of multiple degradation products. The most abundant compounds that were formed by radiolysis resulted from cleavage of the C_carbonyl–N and C_ethylhexyl–N bonds, generating di-ethylhexylamine and mono-ethylhexyl-isobutyramide. Acid contact did alter the radiolytic pathways, with acid favoring cleavage of the C_carbonyl-N bond, while a more diverse array of compounds was formed in the absence of acid. Pulsed radiolysis experiments were also conducted, in which picosecond bursts of energetic electrons were used to irradiate solutions of dodecane containing DEHiBA; formation of the dodecane radical cation was implicated, which serially reacted with DEHiBA to form a radical or radical cation species intermediate in the formation of the observed products. The slow degradation kinetics suggests that DEHiBA possesses good potential for selective extraction of uranium in fuel cycle extraction operations.     

过氧化物交联EPDM与树脂直接粘合的机理分析

文中研究了用DCP交联的EPDM和改性聚苯醚（mPPE）直接粘合的机理。另外,还用聚酰胺66（PA66）和聚甲醛（POM）代替mPPE进行了研究。为了分析界面,用氯仿溶解了mPPE。在采用ATR—FT—IR光谱法分析时发现,在界面形成了mPPE交联层,该交联层是因DCP从EPDM迁移至mPPE中后形成的。在180℃的交联温度下采用电子自旋共振（ESR）法检测出mPPE混合物中的碳自由基和DCP。另一方面,在EPDM／PA66粘合物中发生了界面破坏,这是因为DCP迁移至PA66中并未有效地影响自由基的产生。     

Relationship between structure and mechanical properties in rubber-toughened epoxy resins

Toughened polymers were prepared by adding CTBN rubbers to DGEBA-type epoxy resins. Structure was varied by altering the type and concentration of hardener, the initial molecular weight of the resin, the amount of Bisphenol A added, and the conditions of cure. Electron microscopy showed that these factors affected both particle size and degree of phase separation: rapid curing inhibited phase separation, and produced small particles. Increasing the molecular weight of the resin, either directly or by reaction with Bisphenol A, improved phase separation. Dynamic mechanical measurements of rubber phase volume proved possible, although T_g of the CTBN rubber coincided with a β process in the epoxy resin. Fracture resistance, measured by G_IC, increased linearly with rubber phase volume. Creep and yield behaviour were also affected by the degree of phase separation.     

Chemical interactions between the carbon fibre surface and epoxy resins

Surface oxides on various carbon fibres were determined after modified oxidation treatment with nitric acid. Improved wetting was investigated by contact angle measurements.The results of these systematic studies are correlated with the mechanical properties of UD-composites, prepared from the matrix precursors with which the wetting experiments have been performed.A possible mechanism of the bonding between epoxy matrix precursors and reinforcing fibres was determined by contact angle measurements, by surface tension measurements and by chemical analysis of the chemisorpted diamine hardener.     

CPE-g-VC共聚树脂结构与性能的关系

采用悬浮溶胀接枝共聚方法合成不同CPE含量的CPE - g -VC共聚树脂 ,对其加工性能和力学性能进行了研究 ,并与PVC、PVC/CPE共混物进行比较。结果表明 :接枝共聚物的加工性能优于PVC和PVC/CPE共混物 ,且其加工性能随CPE含量增加而逐渐改善 ;在CPE含量相同时 ,CPE - g -VC共聚物的冲击强度大于PVC/CPE共混物 ,冲击强度随CPE含量的增加而增强 ;当CPE含量相同时 ,CPE -g -VC共聚物的冲击强度随接枝率增加而增强 ;相近CPE含量的接枝共聚物的屈服强度大于共混物。