Linear all-ortho oligomers of phenol–formaldehyde resins. I. Preparations,characterizations, and solution properties

Three kinds of all-ortho methylene-linked phenolic oligomers, i.e., 4-tert-butylphenol (BP), phenol (AO), and O-methylated BP (BPM), were prepared with good yields and their dilute solution properties were studied. In acetone, all of these oligomers are highly solvated and molecularly dispersed. In chloroform, however, AO and BP molecules strongly form hydrogen bonds among themselves. By intramolecular and intermolecular hydrogen-bondings, a large portion of the dimers and the trimers of AO and BP associate to form bimolecular aggregates in chloroform, assuming pseudo-cyclic conformations analogous to calix [4] arene and calix [6] arene, respectively. By intramolecular hydrogen-bonding, the tetramers and the hexamers also form pseudo-cyclic conformations by themselves in chloroform. © 1993 John Wiley & Sons, Inc.     

Structural characterization of monomeric and oligomeric arylamides by solution and solid‐state NMR spectroscopy

An extensive study of both liquid‐ and solid‐state NMR spectroscopy was undertaken in order to elucidate the structural features of a phenyleneterephthalamide oligomer (OPTA) and of some related diarylamides. 1D‐ and 2D‐COSY measurements allowed us to assign completely the proton signals of the title compounds in solution, while 1D‐, 2D‐HETCOR and 2D‐COLOC measurements were used to assign ¹³C resonances. Solid‐state ¹³C NMR experiments, by conventional cross‐polarization (CP) at different contact times and with the dipolar dephased CP technique, were used to characterize these molecules in the solid state. Such techniques allowed us to differentiate among different carbon atoms; in the resulting spectra it was then possible to observe the selective appearance of signals from protonated and quaternary carbon atoms. It was also ascertained that the limited structural mobility of the insoluble OPTA, existing as a single monophasic species, can be explained in terms of hydrogen‐type bonds present in the solid state. Copyright © 2002 John Wiley & Sons, Ltd.     

丙烯酸基蓖麻油氨基甲酸酯齐聚物的合成和表征

合成和表征了丙烯酸基蓖麻油氨基甲酸酯齐聚物(VTPU)。证明:2,4-甲苯二异氰酸酯(2,4-TDI)与丙烯酸羟乙酯(HEA)封端反应生成丙烯酸基单异氰酸酯(IPT)为二级反应。同样,ITP与蓖麻油(CAO)扩链反应亦为二级。通过对缩合反应速率常数和表观活化能的研究表明:VTPU的结构主要由2,4-TDI中对位和邻位二异氰酸基的活性差异所控制,而齐聚物表观粘度与二异氰酸酯的结构规整性有关。动态粘弹谱测试表明:当VTPU中硬链段含量为59%时,聚合物呈分相结构,抗张强度最高为18.2MPa,若增加至67%时,在100.7℃呈现单一转变峰,动态模量因而下降。     

Combinatorial synthesis of oligo(phenylene ethynylene)s

The combinatorial synthesis of oligo(phenylene ethynylene) tetramers, both in solution and on solid support, is described. These products are of interest for molecular electronics applications. An iterative sequence, coupling of aryl halides to alkynes under Sonogashira conditions, was used. Five monomers functionalized with electron-donating or electron-withdrawing groups were synthesized, and used to generate a library of 25 trimers in a solution-phase based process. A library of 24 tetramers was prepared by subsequent protodesilylation and coupling with the alligator clip 4-iodo-1-thioacetylbenzene. The solution-phase based sequence was successfully adapted to a higher yielding directed split-and-pool solid-phase process, with average yields of 78–86% for each step over seven steps. A triazene linker group was used to attach the starting monomer to the polymer beads. At the completion of the solid-phase-based process, traceless cleavage of trimers from the resin was achieved by sonication of the resin in 10% HCl/THF solution. The released products were then poised for the final step in the sequence, attachment of the alligator clip.     

(苯胺齐聚物-b-聚乙二醇)_3星型刚柔嵌段共聚物的合成

采用3种合成策略来制备(苯胺齐聚物-b-聚乙二醇)3三臂星型刚柔嵌段共聚物,获得了预期的目标产物.对每一种合成策略中各阶段的产物进行了结构表征,分析讨论了氧化偶联策略A和"先臂后核"缩合策略B的优点以及存在的问题,最终发展了简单、高效的"先核后臂"缩合策略C,即从均苯三甲酰氯和氨基/羧基封端苯胺四聚体出发,通过酰基化反应得到单分散的苯胺四聚体星型中间体M03,然后以1-乙基-(3-二甲基氨基丙基)碳酰二亚胺盐酸盐(EDCI)和4-二甲氨基吡啶(DMAP)为催化剂,使星型中间体M03与聚乙二醇单甲醚(m-PEG 550)经过脱水缩合反应得到(苯胺四聚体-b-聚乙二醇)3星型刚柔嵌段共聚物,并用红外光谱、质谱、核磁氢谱等进行了表征,表明所获得的产物与预期结构一致.     

Synthesis and Thermal Properties of a Novel Schiff Base Oligomer with a Double Azomethine Group and its Co(II) and Mn(II) Complexes

Schiff base oligomer of N,N′‐bis (2,4‐dihydroxybenzylidene) 1,2‐phenylenediamine (DHBPDA), with a double azomethine group, was synthesized from the oxidative polycondensation (OP) reaction with NaOCl as an oxidant in an aqueous alkaline medium at 90°C. About 75% DHBPDA was converted to O‐DHBPDA. The structures of the products were studied by UV‐Vis, FT‐IR, ¹H‐NMR, ¹³C‐NMR and elemental analysis. According to Gel Permeation Chromatography (GPC) analysis of O‐DHBPDA, the number average molecular weight (M_n), weight average molecular weight (M_w) and PDI values were found to be 4328 g mol^?1, 6228 g mol^?1 and 1.43, respectively. TG/DTA analyses were shown to be stable of O‐DHBPDA against thermo‐oxidative decomposition. During the polycondensation reaction, a part of the azomethine (‐CH?N‐) groups oxidized to aldehyde (CHO) group (10–12%). Oligomer‐metal complexes of oligo‐N,N′‐bis (2,4‐dihydroxybenzylidene) 1,2‐phenylenediamine (O‐DHBPDA) with Co(II) and Mn(II) were synthesized and characterized by FT‐IR, UV‐Vis, TG‐DTA and Atomic Absorption Spectroscopy (AAS). The residue of DHBPDA, O‐DHBPDA, O‐DHBPDA‐Co and O‐DHBPDA‐Mn were found to be 0%, 3.65%, 11.67%, and 9.20%, respectively at 1000°C.     

对硝基苯酚亚甲基桥齐聚物的苯并二(口恶)环衍生物的合成

本文研究了二(对硝基苯氧基)-甲烷或对硝基苯酚在浓硫酸的存在下与过量多聚甲醛的反应,合成得到含两个和三个苯环的对硝基苯酚亚甲基桥齐聚物的苯并二噁环衍生物。柱层析分出四个纯品,经IR,~1H NMR,MS分析鉴定,其中三个为新化合物。这类化合物作为合成子可用于硝基取代的杯芳烃或长链亚甲基桥齐聚物的收敛性分步合成。     

环状聚芳酯低聚物的核磁共振谱峰的归属

本文报道了环状聚芳酯低聚物的核磁共振碳谱及氢谱。测定了其碳及氢的自旋晶格驰豫时间，通过与类似物质标准谱图的比较、自旋晶格驰豫时间的分析以及化学位移取代基效应的计算等，归属了其碳氢谱峰。     

用差减红外光谱分峰法测定乙丙齐聚物中端羟基的微结构

合成了端羟基乙丙齐聚物。用差减红外光谱对端羟基进行了分析。扣除了溶剂中三氯甲烷的干扰,用RUN.CAPR程序进行分峰,以正戊醇-1、3-甲基丁醇-1和丁醇-2为模型化合物标定伯、仲羟基吸收峰位置,并进行蜂面积积分,用模型化合物回归处理后得到定量公式:A=15.8667×10~3Cp+0.25674,以此求得乙丙齐聚物中伯、仲羟基的官能度。