Structural Effects on the Adhesive Properties of Butadiene/Styrene Radial Teleblock Copolymers

The effects of butadiene/styrene ratio, monomer distribution, and molecular weight distribution and branching on the pressure sensitive adhesive properties of butadiene/ styrene radial teleblock copolymers are reported. Styrene content of polymers with varying structures shows a close relation with tack response, and styrene content and structure affect solution viscosity and shear adhesion. When part of the styrene is incorporated into the polybutadiene segment to yield a block progressively enriched in styrene (tapered block), solution viscosity and shear adhesion are reduced. When the butadiene segment is replaced by a block of randomly copolymerized butadiene and styrene, the polymers provide lower solution viscosities and shear adhesion but unchanged tack.

The molecular weight distribution of the radial teleblock polymers can vary from broad, highly branched compositions to narrow molecular weight distributions of almost Iinear polymers. The latter have relatively high solution viscosity and low shear adhesion, whereas the former polymers produce moderate solution viscosity but high shear adhesion. Tack is generally unaffected.     

Apparent Molar Volumes of N,N – Disubstituted Monoamides: A Convenient Tool to Interpret Iron(Iii) Extraction Profiles from Hydrochloric Acid Solutions

New iron(III) extraction data involving two N,N-disubstituted monoamides, N-ethyl-N-phenyloctanamide (EPHOA) and N-ethyl-N-cyclohexyloctanamide (ECHOA), from hydrochloric acid media, are presented and discussed. These, and earlier results obtained with other similar N,N-disubstituted monoamides, are interpreted in this work through their apparent molar volumes in 1,2-dichloroethane, and all the information is being used to screen for solute-solute and solute-diluent interactions. The results collected help to understand why N-cyclohexyl monoamides are generally more efficient than their N-phenyl analogues as liquid-liquid extractants for iron(III) from 3 to 5 M hydrochloric acid solutions, and clearly denote that N-phenyl monoamides are essentially monomeric whereas N-cyclohexyl monoamide derivatives have a tendency to aggregate in the organic solution.     

Synthesis of novel pseudo‐Fréchet‐type dendrons and their fluorescent enhancement to Eu3+ ion

Novel pseudo‐Fréchet‐type dendrons with 1,3,5‐triazine structure G1.0(NOT) and G2.0(NOT) were synthesized under mild conditions by cyanuric chloride, β‐naphthol, and 3,5‐dihydroxybenzyl alcohol with the yields of 96.3 and 85.6%. The structure of the dendrons was characterized by elementary analysis, IR spectrum, ¹H‐NMR, and FAB‐MS. The dendrons had good thermo stability and solubility. They could partially transfer their absorbed energy to Eu³⁺ ion in tetrahydrofuran/acetone solutions. When the concentration of G1.0(NOT), G2.0(NOT), and Eu³⁺ ion was 5 × 10^?4 mol/L, G1.0(NOT) could enhance the fluorescent intensity of Eu³⁺ ion at 613 nm by 4.2‐fold, whereas G2.0(NOT) could enhance the fluorescent intensity of Eu³⁺ ion at 465 and 613 nm by 18.6‐ and 11.7‐fold, respectively. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

PVC螺纹紧固密封可伸缩接头在煤层气输送管路中的应用

使用聚氯乙烯(PVC)螺纹紧固密封可伸缩接头对煤层气输送PVC管路进行连接,解决了传统钢制对合管接头在收缩时容易泄露、聚乙烯法兰套胶粘接头在极端严寒气候条件下易断裂等问题,该接头施工方便、安装快捷、密封可靠、省工省时,特别适用于严寒地区.     

Mixtures of poly(vinyl chloride) and copolyesters based on ε‐caprolactone and L‐lactide: Miscibility,thermal stability,and weathering resistance

Properties of the blends of Poly(vinyl chloride) (PVC) and poly(ε‐caprolactone) (PCLO) and copolyesters based on ε‐caprolactone and L‐lactide (LLA) prepared by rolling were studied. Incorporating the LLA units into the structure of PCLO the content of the crystalline phase was controlled. Miscibility of the blends was assessed using DMA, and basic mechanical properties were correlated with the type and content of the polymer plasticizer. The PVC blends containing up to 20 wt parts polyesters were miscible. The presence of the LLA units in the copolyester influenced negatively the thermal stability. On the other hand even small content of copolyester in the blend enhanced the resistivity against aging. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

氨基硫脲对锌在氯化铵介质中的缓蚀作用及其吸附行为

采用失重，腐蚀电位测试，交流阻抗等方法研究了氨基硫脲对锌在２６％氯化铵介质中的缓蚀作用机理，研究结果表明，ＴＳＣ对锌在氯化铵中的腐蚀有较好的抑制作用，其作用机制为几何覆盖效应。ＴＳＣ在锌表面的吸附近似符合Ｌａｎｇｍｕｉｒ等温式。     

亚磷酸二甲酯尾气中氯甲烷回收的工艺实践

本文介绍了从亚磷酸二甲酯生产尾气中回收氯甲烷的工艺，采用降温干燥，固碱干燥和压缩相结合的方法，可使回收氯甲烷的浓度达９９％以上。     

活性白土生产废酸重复利用工艺研究

在制活性白土时添加ＫＣｌ，使其废酸得以重复利用 。     

复混肥料中氯化物含量分析测试的研究

采用电位滴定法对复混肥料中氯化物含量进行准确测定，克服了化学分析法的不足，重现性好，便于推广应用。     

月桂酰苯甲酰甲烷的合成及其对聚氯乙烯辅助热稳定性能的研究

以月桂酸甲酯和苯乙酮为原料,通过克莱森缩合反应,合成了一种具有β-二酮结构的月桂酰苯甲酰甲烷,用红外光谱、核磁共振波谱对产物结构进行了表征。考察了反应条件对产物收率的影响,最佳的合成工艺条件为:二甲苯为溶剂,新鲜甲醇钠为催化剂,n(月桂酸甲酯):n(苯乙酮)=1.2:1,回流温度下反应3 h,收率可达85%。研究了其作为聚氯乙烯辅助热稳定剂的热稳定性能,结果表明,所制备的月桂酰苯甲酰甲烷是一种优良的聚氯乙烯用无毒辅助热稳定剂。