Table of Content

30 March 2000, Volume 20 Issue 1    Next Issue

研究报告

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SYNTHESIS OF ALKYL-POLYGLYCOSIDE CATALYZED BY SOLID ACID LUO Fang;XIN Xiao-yan 2000, 20 (1):  11-14.  Abstract ( 670 )   PDF (813KB) ( 825 )   Save Reaction catalyzed by solid super acid to synthesize alkyl-polyglycoside is reported.The best reaction activity of solid super acid catalyst is discussed.The conversion of glucose arrived to 99%. Related Articles | Metrics

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EFFECT OF VEGETABLE TANNINS ON BEER STABILITY Qin Qing;ZHONG Chong-mao 2000, 20 (1):  15-20.  Abstract ( 808 )   PDF (853KB) ( 751 )   Save Tannin, which is a secondary metablite of plants and gets into beer from barley and hop in processing of beer, is an important ingredient in beer.Tannins in barley are condensed tannin consisting chiefly of dimeric and trimeric proanthocyanidins.In the process of saccharification and elution, the content of these oligomeric proanthocyanidins is reduced abruptly through oxidization into polymeric tannins.Tannins in hop consist of hydrolyzable tannins and condensed tannins, containing anthocyanin and odies tannins which inhibit muddy and improve colloidal stability of beer.Chinese gallotannin is hydrolyzable tannin.When Chinese gallotannin is put into wort and beer at 6g/100L, the macromolecular nitrogenous substance is reduced 5mg/100L in wort, the formation of diacetyl is also reduced, and the colloidal stability and flavour stability of the beer are improved. Related Articles | Metrics

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STUDY ON COMPONENTS,SEPERATION AND UTILIZATION OF BY-PRODUCTS IN TERPINEOL PRODUCTION HU Gui-xian;ZHAO Zhen-dong;LI Dong-mei;HU Xi-e;LIU Xian-zhang 2000, 20 (1):  1-5.  Abstract ( 836 )   PDF (1273KB) ( 1196 )   Save Components of by products in the terpineol production were analyzed by GC and GC-MS.The results showed that main compounds in the by products were α-pinene, camphene, α-terpinene, 1, 8-cineol, limonene, γ-terpinene, terpinolene and terpineol.They can be separated by rectification, or dehydrogenated to create useful p cymene for further utilization. Related Articles | Metrics

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MECHANISM OF MUTUAL ENHANCING ABILITY OF PURIFICATION BETWEEN PHOTOCATALYSIS AGENT AND ACTIVE CARBON ON AIR PURIFICATION SIEVE GU Zheng-rong;CHEN Ai-ping;DAI Zhi-ming;GU Hong-cheng 2000, 20 (1):  6-10.  Abstract ( 602 )   PDF (640KB) ( 1200 )   Save Nano TiO2 was dip-coated on active air purification sieve of active carbon.The purification effect of this sieve against various polluting gases were investigated.The result showed that purification effects on H2S, NH3, HCHO, CO, and toluene were notably enhanced throush degradation of pollutants by photocatalysis agent under UV irradiation, which resulted in enhanced purification ability of active carbon. The adsorption effect of active carbon provided a high-concentration environment to increase the reaction rate. Related Articles | Metrics

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EFFECT OF WOOD AGE ON THE PULPING CHARACTERISTIC AND CHEMICAL COMPOSITION OF EUCALYPTUS GLOBULUS XIE Yi-min;WU Hong;ZENG Zhi-tong;LAI Yan-ming 2000, 20 (1):  21-26.  Abstract ( 706 )   PDF (1030KB) ( 666 )   Save Eucalyptus globulus is one of the hardwood species suitable for papermaking.The pulp yield is high and the alkali consumption is relatively low when kraft process is used.The pulping characteristics of E.globulus depend on their wood ages.In the present study, three kind of wood chips of E.globulus of 6, 10 and 18 years old were used in pulping experiment by chemical analysis in order to clarify the effect of wood age on chemical components and their pulping characteristics.The results showed that the sequence of pulp Kappa number obtained in the same condition is 6 years>10 years>18 years.However, the sequence of pulp yield obtained in the same condition is 18 years>10 years>6 years.It was found that 1% NaOH extractive content, holocellulose content, lignin content and neutral sugar composition were main factors influencing the pulping characteristics of wood chips with different wood ages. Related Articles | Metrics

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STUDY ON THE SYNTHESIS OF ACRYLPIMARIC ACID POLYETHYLENE GLYCOL ESTER POLYETHER POLYOLS XIE Hui;CHENG Zhi 2000, 20 (1):  27-32.  Abstract ( 547 )   PDF (1280KB) ( 653 )   Save Ring opening of copolymerization and homopolymerization between acrylpimaric acid and ethylene oxide at different mole ratio were studied.Effects of various factors on reaction rate and polymerization degree of ethylene oxide on properties of products were discussed.The IR spectroscopy and thermal stability were also discussed.It was found that polyether polyols, as a new type of polyol could be used in polyurethane paint. Related Articles | Metrics

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BRIGHTNESS STABILIZING EFFECT OF UV-ABSORBERS AND RADICAL TRAPPER ON POPLAR APMP PULPS FANG Gui-gan;CASTELLAN Alain;SHEN Zhao-bang 2000, 20 (1):  33-40.  Abstract ( 629 )   PDF (1633KB) ( 652 )   Save The light-induced colour reversion (yellowing) of high yield pulps was mainly due to sensitivity of the specific structure in lignin to UV or near UV light combining with oxygen in the air producing chromophores through forming the intermediate free radicals. Application of UV absorbing compounds and radical trapper or antioxidants onto paper have been reported to stabilise the brightness against light exposure. This paper reports the investigations on application of UV absorbers (Tinuvin 1130 and its ester precusor), nitroxide free radical (a free radical trapper) and polyethlene glycol 300 (an antioxidant) onto poplar APMP handsheets. The effects on non treated and reduced pulps and with organic solvent solution or aqueous solution of additives were compared. The results show that application of Tinuvin 1130 mixed with dodecanol combining with reducing treatment of pulp could provide the handsheets with significant protection from yellowing.This technique was most close to commercial applications. Related Articles | Metrics

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SYNTHESIS AND PROPERTY OF DIMALEOPIMARIC ACID TYPE POLY(URETHANE AMIDEIMIDE)BAKING PAINT LI Chun-cheng;SONG Zhan-qian 2000, 20 (1):  41-46.  Abstract ( 687 )   PDF (1135KB) ( 650 )   Save A head-to-head, end-to-end structural polyamideimide(PAI)baking paint was synthesized from the reaction of dimaleopimaric acid with di isocyanates, and modified by means of copolymerization with dihydric alcohol to prepare poly(urethane-amideimide)(PUAI)baking paint.The PAI and PUAI was characterized by IR and TG.The results showed that PUAI baking paint possesses both excellent mechanical properties and thermostability, which could be used as F grade insulting varnish. Related Articles | Metrics

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ANALYSIS OF DTA/TG CURVE OF PHENOLIC RESIN DIPPED WOOD POWDER HU Shu-yi;HUANG Bi-zhong 2000, 20 (1):  47-51.  Abstract ( 871 )   PDF (1106KB) ( 1395 )   Save Differential thermal analysis method was used by analyzing the differential thermal curve and thermogravimetric curve(DTA/TG)of wood powder, phenolic resin and dipped wood powder.This method revealed the dynamic state in pyrolysis of phenolic resin dipped wood powder, and investigated the structure and property of wooden resin compound timber. Related Articles | Metrics

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STUDY ON PROMOTING EFFECTS OF NaOH PRETREATMENT ON WOOD BLEACHING CHEN Yu-he;HUANG Wen-hao;CHANG De-long;HU Wei-hua 2000, 20 (1):  52-56.  Abstract ( 1059 )   PDF (917KB) ( 1228 )   Save It was studied in this paper that the effects of aqueous alkali on the penetration and the color of paulownia wood after soaking in NaOH aqueous solution.It was also investigated the promoting effects of this solution on wood bleaching.The result showed that NaOH could increase wood penetration and bleaching effect without damage to wood color.After soaking in 0.3% NaOH aqueous solution for 2 days, the samples were treated in 2% Na 2S 2O 4 for 3 days.Half a year later the lightness and whiteness of these samples were obviously higher than the untreated samples, and the chromatism was lower than that of the untreated samples. Related Articles | Metrics

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SYNTHESIS,STRUCTURE AND PROPERTIES OF LIGHT COLOR BISPHENOL PHENOLIC RESIN MODIFIED BY OLEIC ACID AND ROSIN ZHOU Wen-fu;MO Yue-qi;JIA De-min 2000, 20 (1):  57-64.  Abstract ( 665 )   PDF (1582KB) ( 886 )   Save A resin with properties of fast drying, good glossiness, good water, acid, and alkaline resistance was synthesized from oleic acid, rosin, bisphenol-A and pentaerythritol.Optimum conditions were studied and the products were analysed by FTIR and TGA. Related Articles | Metrics

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A BRIEF DISCUSSION ON MANUFACTURE OF HIDE POWDER FOR TANNIN ANALYSIS Lü Xu-yong 2000, 20 (1):  71-74.  Abstract ( 749 )   PDF (527KB) ( 1046 )   Save Hide powder is an important chemical reagent for determination of tannin content in vegetable tanning materials.In this article the history of manufacture and development for hide powder in China, main points of its processing technique and suggestions for improvement are introduced. Related Articles | Metrics

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STUDIES ON THE ACID HYDROLYSIS OF VALONEA EXTRACT RESIDUES FOR FODDER YEAST PRODUCTION WANG Yu-hua;WANG Zong-li;LU Shu-xia;ZHOU Guo-an;TAN Bai-qi;SONG Zhi-cui;HE Yuan-lu 2000, 20 (1):  65-70.  Abstract ( 653 )   PDF (1349KB) ( 719 )   Save In China, about 130, 000 tons of different kinds of extract residues are obtained per annum in the tannin extract industrial production. To find an effective pathway for utilization of this resource has a very important significance.This work is concerned in the production of fodder yeast from tannin extract residues using acid hydrolysis method.Its main purpose is to clarify whether the tannin extract residues as raw material are suitable to the percolation hydrolysis technology at high temperature using dilute sulfuric acid, and meanwhile to investigate the conformability of the hydrolyzate neutralized as substrate for the fodder yeast fermentation.The chemical analytical data of five kinds of tannin extract residues from four manufactories showed that the sugar content of two valonea extract residues is the highest, up to 56.78% and 59.70%, respectively.Therefore these residues were chosen as raw materials in this experiment.When these residues were subjected to hydrolysis for 60 minutes with dilute sulfuric acid from 0.5% to 0.8%, at temperatures from 180 to 190℃, its sugar yields averaged about 40%, corresponding to 67% of the theoretical sugar yields, approximating to the general level of hydrolysis industrial production.When the substrate was fermented with Candida tropicalis, the yeast yields range from 36.71% to 39.80% of the reducing sugar content, and the protein content of yeast amounts from 43.64% to 48.68%, approximating to the general level of hydrolysis industrial production.Research results revealed that utilization of valonea extract residues for production of fodder yeast is basically feasible by means of acid hydrolysis in respect of technique.The production cost is economically near to that from other kinds of raw material used in hydrolysis industry. Related Articles | Metrics

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COMPARISON STUDY ON THE VARIATION OF ESSENTIAL OIL IN CULTIVATED V.PSEUDOFFICINALIS DURING ITS GROWTH GU Li;GU Cheng-hua;ZHANG Yong-kang 2000, 20 (1):  75-79.  Abstract ( 456 )   PDF (2093KB) ( 810 )   Save Variations of chemical composition and contents of essential oil in cultivated Valeriana pseud off icinalis during its various growth stages were analysed by GC/MS/DS.Relations between composition and content of essential oil from different parts, ages and storage time of the plant material, were also studied which are important and of practical significance to the exploitation of V.pseudofficinalis. Related Articles | Metrics

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DEVELOPMENT OF RESEARCH ON CATALYTIC ESTERIFICATION OF ROSIN HAO Qiang;HA Cheng-yong 2000, 20 (1):  80-86.  Abstract ( 792 )   PDF (911KB) ( 1656 )   Save The development on research of catalytic esterification of rosin in the past 30 years are summarized.Conditions and catalysts used in the reaction are specially noted and compared.It is pointed out that enforcement of such researches on rosin esterification is helpful for better utilization of rosin resources in China.Fifty two references are cited. Related Articles | Metrics