Morphology and properties of poly[2‐methoxy‐5‐(2′‐ethyl‐hexyloxy)‐para‐phenylene vinylene]/silica nanoparticle hybrid films

Poly[2‐methoxy‐5‐(2′‐ethyl‐hexyloxy)‐para‐phenylene vinylene] (MEH‐PPV)/silica nanoparticle hybrid films were prepared and characterised. Three kinds of materials were compared: parent MEH‐PPV, MEH‐PPV/silica (hybrid A films), and MEH‐PPV/coupling agent MSMA/silica (hybrid B films), in which MSMA is 3‐(trimethoxysilyl) propyl methacrylate. It was found that the hybrid B films could significantly prevent macrophase separation, as evidenced by scanning electron and fluorescence microscopy. Furthermore, the thermal characteristics of the hybrid films were largely improved in comparison with the parent MEH‐PPV. The UV‐visible absorption spectra suggested that the incorporation of MSMA‐modified silica into MEH‐PPV could confine the polymer chain between nanoparticles and thus increase the conjugation length. The photoluminescence (PL) studies also indicated enhancement of the PL intensity and quantum efficiency by incorporating just 2 wt% of MSMA‐modified silica into MEH‐PPV. However, hybrid A films did not show such enhancement of optoelectronic properties as the hybrid B films. The present study suggests the importance of the interface between the luminescent organic polymers and the inorganic silica on morphology and optoelectronic properties. Copyright © 2004 Society of Chemical Industry     

Head-to-head polymers: 33. Bromination of cis-1,4-polybutadiene to head-to-head poly(vinyl bromide)

Cis-1,4-polybutadiene (PB) in a 0.5% solution of a solvent mixture of dichloromethane and 1,2-dibromoethane or tetrahydrofuran was quantitatively brominated with elemental bromine at 0°C under careful exclusion of oxygen to head-to-head poly(vinyl bromide). Partially brominated PB has a structure of random or block sequences of butadiene units in the polymer depending on the bromination solvent but shows no stereospecificity in the CHBrCHBr-dyads. Partially brominated PB with block structure showed a microphase-separated morphology over a wide range of composition. Microphase separation is less pronounced for the more random structure of butadiene units. I.r and ¹³C n.m.r. spectroscopy of the partially brominated PB was used to follow the progress of the bromination.     

薄层层析－溴化法测定水胺硫磷

水胺硫磷目前常用的分析方法有气相色谱法，液相色谱法，薄层层析－总磷比色法，定氮法。我们根据水胺硫磷的理化性质和化学结构的特点，采用了薄层层析－溴化法。此方法简便易行，准确可靠，不受标准品的限制。     

3-氯-4-（2-溴甲基-4-甲基-1，3-二恶戍烷-2-基）苯基-4’-氯苯基醚的合成

3-氯-4-（2-溴甲基-4-甲基-1，3-二恶戍烷-2-基）苯基-4’-氯苯基醚是杀菌剂苯醚甲环唑的一个重要中间体。以2-氯-4-（4-氯苯氧基）-苯乙酮为起始原料，采用溴化和合环同时进行的合成工艺制得该化合物，收率90％．产品含量95％。优化了反应条件，简化了操作。     

Rheological properties and compatibility of NR/EPDM and NR/brominated EPDM blends

Ethylene–propylene–diene terpolymer (EPDM) was modified by bromination reaction. Blending the resulting brominated EPDM with natural rubber (STR5L) and blending the unmodified EPDM with STR5L at various compositions were carried out. The rheological properties of the blends were investigated using a capillary extrusion. Shear flow curves of the pure rubbers and their blends illustrated the pseudoplastic property as shear thinning behavior with a power law index n < 1. True shear viscosity of all blends showed the negative deviation in relation to their additive values. Rheological behavior and two T_g's found from the DSC thermograms at all blend compositions indicated blend incompatibility for both sets of blends. The incompatibility of the vulcanized blends was also found by measuring the spin–spin relaxation time T₂ by pulsed NMR. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 837–847, 2003     

溴素法α-溴代间氯苯丙酮合成研究

在金属卤化物催化剂 HD2 0 0 1存在下 ,溴与间氯苯丙酮在乙酸中反应得到盐酸安非他酮中间体 α-溴代间氯苯丙酮。最佳反应条件是 :n(间氯苯丙酮 )∶n(溴 ) =1∶ 1 ,催化剂用量为 1 %(质量分数 ) ,溴滴加时间为 1 h,反应温度为 1 0°C,此条件下 ,产物纯度为 98.83%,收率为 96.1 %。     

2-氨基-5,6-二氢一苯并噻唑-7(4H)-酮的合成与表征

以1,3-环己二酮(Ⅰ)为原料,在水相中与溴进行溴化反应制备2-溴-1,3-环己二酮(Ⅱ),产物未经提纯,直接将II与硫脲在乙醇介质中回流反应6 h合成了目标产物2-氨基-5,6-二氢-苯并噻唑-7(4H)-酮(Ⅲ),总收率为74%,合成产品通过乙醇重结晶进行了纯化,并通过核磁共振氢谱进行了结构确证。     

溴代反应中的选择性溴化剂

综述了四溴环酮，过溴型季铵盐等选择性溴化剂在溴代反应中的应用。     

Synthesis and properties of bromide‐ functionalized poly(isobutylene‐co‐p‐ methylstyrene) random copolymer

Poly(isobutylene‐co‐p‐methylstyrene) (IB/p‐MS) random copolymer is a new generation of polyisobutylene‐based elastomers. The cationic copolymerization of IB with p‐MS was thoroughly examined by using 2‐chloro‐2,4,4‐trimethylpentane/ethylaluminiumsesquichloride/electron donor as initiating system. IB/p‐MS random copolymers with high molecular weight were obtained at elevated temperature through the addition of ethyl acetate; the reaction proceeded in a mildly exothermic manner. Although the reactivity ratios of comonomer pairs differ by close to an order of magnitude, p‐MS was uniformly distributed in the chains. IB/p‐MS random copolymer can be brominated by adding molecular bromine into the copolymer solution, thereby yielding a completely saturated polymer backbone with a chemically reactive site. The types and selection of appropriate vulcanization systems for bromide‐functionalized IB/p‐MS random copolymers are also discussed. © 2016 Society of Chemical Industry     

模块化微反应系统内溴化间甲基苯甲醚连续合成

根据微化工技术发展的主要趋势,针对4-溴-3-甲基苯甲醚间歇非均相合成技术存在的问题,以微筛孔反应器与玻璃微珠填充床为核心功能微设备单元构建了模块化微反应系统,并在此模块化微反应系统内对液-液非均相连续溴化合成4-溴-3-甲基苯甲醚开展研究。通过优化操作条件,在溴浓度(x_{\mathrm{B}{\mathrm{r}}_{\mathrm{2}}})为17.5%（质量分数）、溴与间甲基苯甲醚摩尔比(n_{\mathrm{B}{\mathrm{r}}_{\mathrm{2}}}/n_M)为1.01、反应起始温度(T)为 0℃、停留时间为0.78 min条件下,4-溴-3-甲基苯甲醚的收率大于98%,多溴代副产物的含量仅为1%。与传统间歇溴化反应相比,模块化微反应系统内连续溴化反应具有十分明显的优势：可将间歇过程连续化,在保证安全的基础上极大地提升了反应的效率（时空收率为6.5×10⁴ kg/(m³·h)）;另外,该过程是由传质控制的,微反应器的传质性能优异,可极大地改善产品的选择性（多溴代副产物的量减少50%）。该研究为4-溴-3-甲基苯甲醚的连续高效安全合成提供了技术和设备依据。