Preparation of light-stable micelles with azo dyes from a nonamphiphilic random block copolymer

Light-stable micelles with azo dyes were prepared by micelle formation of a nonamphiphilic diblock copolymer containing azobenzene and UV absorbent at ca. 1 mol% as the unit ratios. The nonamphiphilic block copolymer consists of two different kinds of random copolymer blocks: poly[4-(phenylazophenoxymethyl)styrene-co-vinylphenol] (P(AS-co-VPh)) and poly[4-(2-hydroxybenzophenoxymethyl)styrene-co-styrene] (P(HBS-co-St)). This random block copolymer, P(AS-co-VPh)-b-P(HBS-co-St) formed the micelles in the presence of 1,4-butanediamine (BDA) through hydrogen bond cross-linking between the VPh units via BDA. The micelles had the azobenzene moieties at the cores and the UV absorbents at the coronas. The micelles showed a small color difference in color fading experiments, in comparison with the unimers and with micelles having no UV absorbent at the coronas. It is significant that the diblock copolymer forms the micelles and has the UV absorbents at the coronas to suppress the color fading. Furthermore, the chain length of ,-diamines had no effect on the hydrodynamic radius of the micelles, but affected the aggregation number and the cmc.     

萝卜木质素的提取及其抗自由基活性

以浓度为80%的乙二醇水溶液为溶剂,采用高沸醇溶剂法(HBS)从萝卜中提取萝卜木质素,采用红外光谱、紫外光谱和~1H NMR等方法对其结构进行了表征.结果表明,所提取的萝卜木质素具有木质素类化合物的典型结构特征.采用可见光分光光度法研究了萝卜木质素对DPPH·自由基和HO·自由基的抑制效率.结果表明萝卜木质素对两种自由基均具有较高的抑制率,其对两种自由基的抑制率最高分别为90%和68.3%.     

Preparation and Properties of HBS Lignin from Masson Pine

In order to establish a new method for making cellulose and lignin from Masson pine, a high boiling solvent (HBS) pulping process with an aqueous solvent of 1,4-butanediol was investigated. Masson pine chips were pulped with a 70%--90% aqueous solution of 1,4-butanediol containing a small amount of a catalyst at 200--220℃ for 60--180 min. HBS Masson pine cellulose is suitable for making paper. Water-insoluble HBS lignin was separated from the liquor reaction mixture by water precipitation. The recovered high boiling solvent (RHBS) is able to be recycled as a pulping solvent, indicating that the HBS method is a pulping process of Masson pine which is energy saving, resources saving and pollution free. HBS lignin has a better chemical reactivity and a lower ash content than lignin sulfonate.     

高沸醇溶剂法提取胡萝卜木质素

以乙二醇水溶液为溶剂,采用高沸醇溶剂法（high boiling solvent,HBS）从胡萝卜中提取木质素。 结果表明,将胡萝卜干粉投入到质量分数为80%的乙二醇中,在210 ℃、料液质量比为1∶6的条件下蒸煮2 h,木质素收率最高（17.79%）。 采用红外光谱（FTIR）、紫外光谱(UV)和核磁共振(1H NMR)等测试技术对其结构进行了表征。 结果表明,高沸醇法提取的胡萝卜木质素具有木质素类化合物的典型结构特征。 通过元素分析和甲氧基含量的测定,得到胡萝卜木质素的C9结构模型为C9H9.62O1.99(OCH3)0.96。 利用Fenton反应产生羟基自由基·OH,研究了胡萝卜木质素对羟基自由基的抑制效率。 结果表明,胡萝卜木质素在较低的浓度（50 mg/L）下对羟基自由基就具有较强的抑制效果,抑制率最高可达64.9%。     

甘蔗渣高沸醇木质素光谱分析与结构测定

甘蔗渣高沸醇(HBS)木质素是高沸醇溶剂法制浆过程中得到的高分子材料。从红外谱图显示,在1 700和1 328 cm-1处存在吸收峰值,说明HBS木质素存在非共轭羰基作用。紫外谱图在201 nm处存在n→π*电子跃迁。表明有较大的不饱和性。从1H NMR图谱中看出存在明显的紫丁香基苯和愈疮木基环结构。实验测定了甘蔗渣HBS木质素的元素组成和甲氧基含量,并计算得到经典的C₉结构模型。其结构形式为C₉H_9.79O_2.58(OCH₃)0.75。其重均分子量测定结果为2 674 g·mol-1。     

Millimeter- and submillimeter-wave spectroscopy of HBS and DBS in vibrationally excited states

Normal and deuterated isotopic variants of thioborine have been produced in the gas phase by a high temperature reaction between crystalline boron and hydrogen sulfide. Millimeter- and submillimeter-wave rotational spectra have been recorded in the frequency range from 75 to 730 GHz for vibrational ground and excited states of the H^10/11B³²S and D^10/11B³²S isotopic species. The spectra of all the excited states which lie below 1500 cm⁻¹, that are 01¹0, 00⁰1, 02⁰0, and 02²0, have been observed and analyzed for each of the four isotopologues investigated. High-order Fermi resonance parameters were found important to analyze properly the spectra of the 00⁰1 and 02⁰0 interacting states. The improved rotational data in conjunction with earlier infrared spectroscopy results have been employed to calculate more precise anharmonic force constants and equilibrium bond lengths.     

Hydrogen bond surrogate stabilized water soluble 310-helix from a disordered pentapeptide containing coded α-amino acids

Replacing a hypothetical i?+?3?→?i peptide H-bond in a disordered pentapeptide, that lacks any helicogenic C^α-tetrasubstituted residues, with a propyl linker and carbamylating the N-terminal nitrogen constrains it in the elusive 3₁₀-helical structure with high helicity and stability under varying conditions of temperature and pH, confirmed by NMR and CD analyses.     

取代基效应(SCS)与乙烯—α—烯烃共聚物的序列结构——7.氢化丁苯共聚物(HBS)

测定了两个氢化丁苯共聚物样品的~1H、~(13)C NMR谱。通过处理文献中的~(13)C NMR谱数据得到了-C_2H_5和-C_6H_5的SCS参数。利用乙烯-α-烯烃共聚物的SCS方法结合DEPTNMR实验技术重新归属了该共聚物的~(13)C NMR谱。明确指出,氢化丁苯共聚物分子链中主链任何一个乙烯单元的两个CH_2在序列分布上分属于二元组和三元组。CH则用三元组来表征。最后,对HBS共聚物的序列分布进行了计算。     

取代基效应(SCS)与乙烯-α-烯烃共聚物的序列结构——7.氢化丁苯共聚物(HBS)

测定了两个氢化丁苯共聚物样品的¹H、¹³C NMR谱。通过处理文献中的¹³C NMR谱数据得到了-C₂H₅和-C₆H₅的SCS参数。利用乙烯-α-烯烃共聚物的SCS方法结合DEPT NMR实验技术重新归属了该共聚物的¹³C NMR谱。明确指出,氢化丁苯共聚物分子链中主链任何一个乙烯单元的两个CH₂在序列分布上分属于二元组和三元组。CH则用三元组来表征。最后,对HBS共聚物的序列分布进行了计算。