羟丙基纤维素接枝改性研究Studyongraftmodificationofhydroxypropylcellulose

1、羟丙基纤维素接枝改性研究（ Study on graft modification ofhydroxypropyl cellulose )Article number: 10044736 (2000) 04000604Study on graft modification of hydroxypropyl celluloseYang Jiamo, Li Shirong, Yu Faquan, Bi Yafan, Chen Xiaoyan(Department of chemical engineering, Wuhan Institute of chemistry, Hubei, Wuhan

2、430073, China)Abstract: the graft copolymerization of hydroxypropylcellulose with methyl methacrylate was carried out by using UV and cerium salts as two initiatorsThe effects of reaction time, temperature, monomer concentration, photosensitizer or initiator dosage on the viscosity of the product we

3、re investigated. Two kinds of initiation were comparedThe optimum operation condition of the reaction is obtainedKeywords: hydroxypropyl cellulose; graft copolymerization; modification; viscosityCLC number: TQ 361.6, document identifier code: AReceived date: 20000509Biography: Yang Jiamo (1949), mal

4、e, Professor of Zhangshu City, Jiangxi. Long term teaching and research work in chemical engineering and Chemical Technology0 IntroductionThe molecular formula for cotton cellulose is (C6H10O5) n, which is formedThe chief constituent of the plant cell membrane. Cellulose in the macromolecular struct

5、ureConsisting of repeated glucose units linked to the 1,4 beta glycosidic bondThe reaction characteristic of cellulose is mainly that its product is inhomogeneousSex and complexity, the molecular structure of the raw material has an impact on the reaction processThe reaction activity is affected by

6、the neighboring functional group and the reaction strip at the same timeThe type of reaction is related to the reactionStep processing products to meet the quality requirements of users more difficult, bigManyof them need to be re modified to improve their performanceGraft copolymerization is one of

7、 the most common and has beenproved by practiceThe modification method with remarkable effect is through two kinds of macromolecular backboneChemically linked with a branched chain to produce a productWith the comprehensive properties of these two molecules, ideal results can be obtainedImprove its

8、physical and chemical properties or use performanceThe new product can be synthesized by the following waysThe purpose of improving its quality or performance:(1) introducing active groups on macromolecular backboneThe initiation of a monomer, copolymerization, and growth ofa polymerBranched chain;(

9、2) by means of "grafting" (chemical combination), a kind ofThe molecular chain of the adduct acts as a branched chain attached to the parent macromolecular backbone;(3) in the process of preparing a polymer, make another kindPolymers are formed simultaneously and are used as branchedchains

10、 with the first polymerTo obtain macromolecular productsThe above reactions can be performed in different ways, such as chain transfer and activityGroup method, radiation method, addition polymerization method and ring opening polymerization method, etc.Etc., this work is to use hydroxypropyl cellul

11、ose, methyl methacrylateThe lipid was the main raw material, which was caused by ceric ammonium nitrate and ultraviolet light respectively,Graft copolymerization was carried out to improve cellulose viscosityObjective and compare the advantages and disadvantages of two different methodsOptimum opera

12、ting conditions1 main raw materials, drugs and instrumentsHydroxypropyl cellulose (HEC): white powder, Hubei bellCheung cellulose company produces an aqueous solution of.W 2% with a viscosity of20000 mPa.s (20 DEG C). Dry 24 h. before useMethyl methacrylate (C5H8O2) molecular weight: 100.12Analytica

13、l, pure, Hubei University chemical plant productionCeric ammoniumnitrate (NH4) 2Ce(NO3) 6 referred to as cerium saltThe molecular weight is 548.32, purity analysis, ShanghaiYuelong Daye Non-Ferrous Metals Co studentsProduction.Pyrogallic acid C6H3 (OH) 3: a molecular weight of 126.11, the analysis o

14、f pure, Guizhou, Zunyi second chemical plant productionRotary viscosimeter: model NDJ-1, Shanghai balance instrument factoryProductionUV initiated graft copolymerization device: Homemade2 experiment procedure and experiment scheme2.1 experimental stepsIn order not to oxidize the reaction process, ni

15、trogen is needed Protection. First, a nitrogen purge unit is assembled to dissolve it through copper ammoniaLiquid, pyrogallic acid solution and phosphate solution, and check the sealsplaced inA certain amount of dried hydroxypropyl cellulose is the reactor,Add proper amount of distilled water and m

16、ix with 2 h for consistencyAfter the entry, the nitrogen is injected 30 min, and the mixture is stirred at the same timeThe salt heats or turns on the ultraviolet light. When the temperature is reached, the meter is addedThe amount of monomer methyl methacrylate, stirring until a predetermined react

17、ion timeThe product is removed and cooled to room temperatureDetermination of viscosity of the productTwenty-second volume fourth Journal of Wuhan Institute of Chemical Technology Vol.22 No.4December 2000 J. Wuhan Inst. Chem. Tech. Dec. 20002.2 experimental programBecause of the influence factors of

18、 graft copolymerization, moreThe orthogonal experiment was used to analyze the effects of various factors on the properties of the productslevel ofby, Ce4+The optimum reaction conditions were obtained and the orthogonal experiment was investigatedSee Table 1, table 2.Table 1 Table 1 level factor of

19、cerium saltTable1, Levels, and, factors, of, reaction, initiated,FactorFactorsHorizontalLevels123Reaction time /hReaction time1 23Initiator dosage /mL = L-LInitiator amount1 23Monomer dosage /mL = L-LMonomer amount10 1520Reaction temperature / temperatureReaction temperature40 5060Table 2 horizontal

20、 factor tables of ultraviolet lightTable2, Levels, and, factors, ofReaction, initiated, by, UV, lightFactorFactorsHorizontalLevels123Reaction time /hReaction time1 23Photosensitizer dosage /mL = L-LPhotosonsiticer amount30 4050Monomer dosage /mL = L-LMonomer amount5 79Reaction temperature / temperat

21、ureReaction temperature40 5060After the orthogonal experiment, in order to investigate the influence of various factors on the viscosity of the productThe influence of degree was analyzed by single factor3 experimental results and discussionAnalysis of the results of 3.1 orthogonal experimentsAccord

22、ing to the table of level factors shown in Table 1 and table 2, according to the orthogonal realThe rule of experiment is to take the orthogonal experiment of each factor independent of each other L9 (34)The results of the two sets of experiments are listed in tables 3 and 4It can be seen from table

23、 3 and table 4 that UV induced graftreactionThe most influential factor was the reaction time, whereas cerium salts were the most influentialThe big factor is the amount of initiator, which is the same as beforeThe results of the study are identicalThe optimum reaction of ceric salt was obtained by

24、orthogonal experimentThe condition is: A3B2C3D2, that is, the reaction time is 3 h, and the initiator is usedThe amount is 2 mL/L, the monomer dosage is 20 mL/L, and the reaction temperature isTable 3 scheme and result of orthogonal experiment initiated by cerium saltTable3, Orthogonal, experiment,

25、plan, and, effect, ofReaction initiated by Ce4+ExperimentSerial numberTest No.ItemItemA B C D viscosityMPa - SViscosity111104026500212155048200313206046500421156032000522204047200623105044500731205043600832106042800 933154046600Yi140400.0 34033.3, 37933.3, 40100 /Yi241233.3 46066.7, 42266.7, 45433.3

26、 /Yi344333.3 45866.7, 45766.7, 40433.3 /rangeLimiteRreur3933.3, 12033.4, 7833.3, 5333.3 /Table 4 scheme and result of UV induced orthogonal designTable4, Orthogonal, experiment, plan, and, effect, ofReaction, initiated, BG, UV, ligheExperimentSerial numberTest No.ItemItemviscosityMPa - SViscosity113

27、054028600214075051500315096046300423076046500524094060600625055058400733095051600834056052200935074055600Yi142133.3 42233.3, 46433.3, 48266.7 /Yi255166.7 54800, 51200, 53833.3 /Yi352500.0 53433.3, 52833.3, 48366.7 /rangeLimiteRreur13033.3, 12566.7, 6400, 5566.6 /50. The optimum operating conditions

28、for UV induced reactions are:A2B2C3D2, that is, the reaction time is 2 h and the photosensitizer dosage is 40ML/L, the amount of monomeris 9 mL/L, the reaction temperature is 50 DEG CFrom the results of the viscosity of two sets of reaction products, the effect of UV irradiation was observedThe effe

29、ct is clearly superior to that caused by cerium salts, i.e., UV inducedThe grafting ratio should be higher than the rate of grafting initiated by cerium saltsThe work was consistent with previous studies7, fourth, Yang Jiamo et al. Study on graft modification of hydroxypropyl cellulose 3.2 single fa

30、ctor analysisAs can be seen from Figure 1 and Figure 2, the reaction time is relative to the two kinds of graftingFig. 1 Effect of reaction time of cerium salt on viscosityFig1, Viscosity, of, graft, copolymer, initiated, by, Ce4+Was, influenced, by, reaction, timeFig. 2 Effect of UV irradiation rea

31、ction time on viscosityFig2, Viscosity, of, graft, copolymer, initiated, byUV, light, was, influenced, by, reaction, timewhenThere is an optimum value for the polymerization reaction, the product viscosity exceeds this valueInstead, this may be the main chain at the beginning of the reactionThe init

32、iation and chain continue, while the reaction time is too long, which will lead to graft copolymerizationThe chain termination reaction accelerated and the grafting rate decreasedThe optimum operation time of the graft copolymerization is greater than that of ceric saltShort,Because the light time i

33、s too long, it is easy to degrade the copolymerAs can be seen from figures 3 and 4, there is a temperature in both of themFig. 3 Effect of reaction temperature of cerium salt on viscosityFig3, Viscosity, of, graft, polymer, initiated, by, Ce4+Was, influenced, by, reaction, temperatureThe optimum val

34、ue is that the temperature range of the reaction is not highUnder the experimental conditions, the extreme value trend is not obvious, and the curve is more gentle,From the orthogonal experimental results, we can see the range analysis and reaction temperatureThe degree of influence is relatively sm

35、all, of course, the temperature can not rise too high, this will guideThe viscosity of the resulting product will decrease and the cost will increaseFig. 4 Effect of UV induced reaction temperature on viscosityFig4, Viscosity, of, graft, copolymer, initiated, byUV, light, was, influenced, by, reacti

36、on, timeFigures 5 and 6 show the effect of the amount of monomeron the viscosity of the productFig. 5 Effect of the amount of cerium salt on the viscosity of monomerFig5, Viscosity, of, graft, copolymer, initiated, by, Ce4+Was, influenced, by, photosensitizer, amountFig. 6 Effect of UV irradiation o

37、n the viscosity of monomerFig6, Viscosity, of, graft, copolymer, initiated, byUV, light, was, influenced, by, photosensitizer, amountFrom the diagram, when the amount of monomer increases, the viscosity of the product increases rapidly, but.Whenthe best value is reached, it is not necessary to conti

38、nue to increase the amount of monomerThe big can only raise the cost of production4 ConclusionA. uses hydroxypropyl salt as initiator and UVin hydroxypropylcelluloseThe graft copolymerization can increase the viscosity of the reaction productsAchieve the purpose of modification, but the effect of li

39、ght is better than that of cerium saltTechnically, cerium salts are easy to initiate and cost lessB. the reaction time and temperature of the two initiation methods are both8 there is an optimum value in the twenty-second volume of Journal of Wuhan Institute of Chemical Technology. More than this va

40、lue will lead to the end of the chain in the reaction processThe reaction accelerates or degrades, resulting in a decrease in viscosityC. the best operation of ceric salt initiated graft copolymerization in this experimentThe reaction time was 3 h, the initiator dosage was 2 mL/L, and the monomer wa

41、s usedThe grafting was initiated at 20 mL/L and the reaction temperature was 50 DEG CThe optimum reaction conditions were as follows: reaction time2 h, photosensitizer dosage 40 mL/L, monomer dosage 9 mL/L, reaction temperature 50 DEG CReference:1 sun zhaijian, Zhou Pu, Liu Qicheng, et al. North M.

42、graft copolymerizationBeijing: Chemical Industry Press, 1992.2 Yang Jiamo, Li Ding, Ding Yi,.Ce4+ salt and acrylonitrile initiatedStudy on graft copolymerization of cellulose J. Journal of Wuhan Institute of Chemical Technology,1997,19 (1): 5 8.3 Zhang Chang. Modified fiber and special fiber M. Beij

43、ing: Chinese stonePress of chemistry, 1993.4 Weiwei Xiao, Ceng Zhenhua. Grafting acrylonitrile and cellulose initiated by ultraviolet lightStudy of copolymerization J. Journal of Chengdu University of Science and Technology, 1986, (4): 20 26.5 Yang Jiamo, Li Shirong, Yu Faquan, et al. Chemical technology progress of M.Beijing: Chemical Industry Press, 1997.6 , Youss