造纸相关外文翻译参考文献.doc
《造纸相关外文翻译参考文献.doc》由会员分享,可在线阅读,更多相关《造纸相关外文翻译参考文献.doc(24页珍藏版)》请在沃文网上搜索。
1、 目 录1英文文献翻译11.1英文文献原文(原文题目)11.2 中文翻译92. 专业阅读书目152.1 当代废纸制浆技术152.2 制浆原理与工程152.3制浆造纸污染控制162.4 加工纸与特种纸162.5 造纸湿布化学172.6 再生纤维与废纸脱墨技术172.7制浆造纸工程设计182.9 造纸化学品的制备和作用机理192.10造纸原理与工程19 1 英文文献翻译1.1 Inorganic Reactions in Chlorine Dioxide Bleaching of Softwood Kraft PulpINTRODUCTIONDue to environmental concern
2、s, elemental chlorine is being replaced withchlorine dioxide (ClO2) for the bleaching of wood pulps. Chlorine dioxideis a very selective bleaching reagentpresence of carbohydrates, thereby preserving pulp quality. In addition, ClO2generates less chlorinated organics or adsorbable organic halides (AO
3、X)compared to chlorine, increasing the attractiveness of chlorine dioxide as ableaching reagent. However, there are issues surrounding the utilization ofchlorine dioxide. Based on oxidation equivalents it is more expensive thanelemental chlorine. Furthermore, the formation of chlorate and chloritede
4、crease its oxidation efficiency, further increasing the cost of bleaching.One of the keys to optimizing a chlorine dioxide bleaching stage is tominimize the formation of chlorate and chlorite. In the past, chlorinedioxide bleaching studies on chlorine pre-bleached pulps have shown thatthe optimal us
5、age of chemical (minimum chlorate and chlorite residues)requires that the end pH be around 3.8.1 However, this may not be true forchlorine dioxide pre-bleaching because residual kraft lignin componentsmost likely differ from the residual lignin in a chlorine pre-bleached pulp. Ithas been shown that
6、lignin structure, particularly phenolic lignin content,directly influences the bleachability of wood pulps.2,3 Therefore, prebleachingwith chlorine dioxide may require different reaction conditions tominimize chlorite and chlorate formation. In this article we report the effectof end pH on the forma
7、tion of inorganic chlorine species during chlorinedioxide pre-bleaching of a softwood kraft pulp.EXPERIMENTALMaterials3,4-Dimethoxyacetophenone, sodium borohydride (NaBH4), p-dibromobenzene,biphenyl, and all solvents were purchased from Aldrich Chemicals and used asreceived. Chlorine dioxide was pro
8、duced by reacting 80% stabilized sodiumchlorite (ACROS) with 1.5 equivalents of potassium persulfate (Fluka) indistilled water at room temperature. The resulting solution was stripped withUHP-nitrogen. Nitrogen gas containing stripped chlorine dioxide was passedthrough a column of sodium chlorite (A
9、ldrich), then scrubbed in coldHPLCwater.Methylveratrylalcohol (MVA) was prepared by reacting 3,4-dimethoxyacetophenonewith 2 equivalents of NaBH4. The reaction mixture was refluxedin 3 : 1 MeOH :H2O for 3 h, neutralized with carbon dioxide, and extractedwith 1,2-dichloroethane. Quantitative conversi
10、on of the acetophenone wasobtained. MS m/z (rel. int.) 182(Mt, 59), 167(87), 153(47), 139(100),124(32), 108(21), 93(50), 77(21), 65(25), 51(11), 43(41). 1H-NMR d1.48(d,3H), 3.90(d,6H), 4.83(q,1H), 6.84(q,1H), 6.86(q,1H), 6.93(d,1H).Chlorine Dioxide Reactions with PulpThe 27 kappa softwood kraft pulp
11、 (12 g OD) was prebleached with chlorinedioxide using a 0.2 kappa factor. The bleaching was carried out at 10% consistencyat 508C for 2 h. The initial pH of the pulp was adjusted using aqueoussodium hydroxide (5 wt%) or sulfuric acid (5 wt%) to achieve a desired finalpH. HPLC grade water (Aldrich) w
12、as used as the makeup water. Polyethylenebags fastened with rubber septa were used for bleaching. Samples forinorganic ion analysis were prepared by injecting 20 mL effluent samplesinto a 7 mL vial and evacuating for 45 s, a 1 mL aliquot of HPLC waterwas then added to the sample, followed by the add
13、ition of a sodium fluorideinternal standard. Effluent samples were taken periodically during the 2 hbleach. Ions were analyzed using an ion-exchange column (Dionex AS9/AG9 guard column) with 2.5 mM sodium borate eluent. The eluent flowrate was 1.75 mL/min. Chemical detection was done by suppressed c
14、onductivityusing a Dionex CD20 conductivity detector. Chlorine dioxideconcentrations were determined by iodometric titration. The quantity ofhypochlorous acid in the reaction medium was determined by trapping withaqueous solutions of dimethylsulfoxide (DMSO). Samples (100 mL) of thereaction mixture
15、were injected into 0.5 mL of cold aqueous solutions containingexcess DMSO (0.25 M, pH adjusted to 8). Trapped samples werequenched after 15 s with a saturated sodium thiosulfate solution. Theresulting dimethylsulfone content was determined by GC using cyclohexanolas an internal standard.Chlorine Dio
16、xide Reactions with MVAMVA reactions were run at 25+18C in an oil bath as previously reported.4The pH of the chlorine dioxide reaction was kept constant by using a pHcontrol feedback loop. Reactions were run in a 100 mL, 4-necked flask. AnOmegaTMpH controller (model PHCN-37) was connected to a Milto
17、n-Roymicro-chemical metering pump (model A771-155S). A sodium hydroxideolution (0.8 M) was delivered to the reaction vessel from a burette viaNalgenew PVC tubing. The alkali addition did not exceed 1% of the totalreaction volume. The reaction mixture was stirred magnetically with aTeflon coated bar.
18、 The pH of the water and chlorine dioxide were adjustedusing aqueous sodium hydroxide (5 wt%) or sulfuric acid (5 wt%) toachieve the desired final pH and mixed for one minute prior to injection ofan aqueous solution of MVA. Samples of the reaction were taken with asyringe through a rubber septum. In
19、 the kinetic experiments sampling wasdone until all MVA or chlorine dioxide was consumed.Organic compound concentrations were determined by gas chromatography.Twenty mL samples of the reaction mixture were quenched eitherby adding 0.5 mL of 0.4 M ascorbic acid or 0.5 mL of a saturated aqueoussodium
20、thiosulfate solution. The quenched samples were extracted with0.5 mL of ethyl acetate containing 0.6 mg/L p-dibromobenzene or biphenylas an internal standard. Thereafter, the samples were dried over anhydroussodium sulfate and made up to 2 mL with ethyl acetate prior to GC analysis.GC analyses were
21、performed on an HP 5890 (splitless injection) instrumentequipped with a flame ionization detector, using He as the carrier gas.Injector and detector temperatures were 2408C and 2808C, respectively. Separationswere achieved on a J&W DB-5 fused silica capillary column(30 m 0.32 mm 0.25 mm). Typical te
22、mperature programs were from458C to 2508C at a rate of 108C/min with an initial time delay of 1 min,and from 1008C to 2708C at 10208C/min. In quantitative studies, pdibromobenzeneor biphenyl was used as an internal standard and therelative peak areas and corresponding response factors were used toca
23、lculate concentrations.All GCMS analyses were conducted using the GC analysis conditions ona HP 5985B GCMS equipped with a DB-5 capillary column. In the EI mode,the electron energy used was 70 eV.1H-NMR spectra were determined on a GE 300 MHz instrument. Sampleswere dissolved in CDCl3. Chemical shif
24、ts are given in ppm downfield fromTMS (tetramethylsilane).RESULTS AND DISCUSSIONA 27 kappa softwood kraft pulp was bleached with chlorine dioxide (ClO2) tovarious end pH values. The quantity of chlorite (ClO22), chlorate (ClO32), andchloride (Cl2) were determined as a function of reaction time and a
- 1.请仔细阅读文档,确保文档完整性,对于不预览、不比对内容而直接下载带来的问题本站不予受理。
- 2.下载的文档,不会出现我们的网址水印。
- 3、该文档所得收入(下载+内容+预览)归上传者、原创作者;如果您是本文档原作者,请点此认领!既往收益都归您。
下载文档到电脑,查找使用更方便
10 积分
下载 | 加入VIP,下载更划算! |
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- 造纸 相关 外文 翻译 参考文献
