常压连续微波辐射法合成聚乳酸-聚乙二醇共聚物

第46卷增刊中山大学学报( 自然科学版)VoL. 46 Sup.2007年6月ACTA SCIENTIARUM NATURALIUM UNIVERSITATIS SUNYATSENIJun.2007Continuous Microwave-Irradiated Synthesis of Poly(D，L-Lactide ) -co-Poly ( Ethylene Glycol )Copolymer Under AtmosphereZHANG Ying-min, WANG Peng, LI Yue, LEI Haifen, JIAO Chun-yan, HAN Ning( Research Center for Green Chemistry and Technology ，School of Municipal andEnvironmental Engineering, Harbin Institute of Technology, Harbin 150090, China)Abstract: Poly (D, L-lactide) -co-poly ( ethylene gycol) copolymer ( PELA) of Intrinsic viscosity0. 51 dL●g"'had been preparedunder continuous microwae-iradiation power of 90 W for 8 min at atmosphere. Effects of poly ( ethylene glycol) ( PEG) content,polymerization time on intrinsic viscosity and yield of PELA had been discussed. Furthermore, temperature rising behavior in reactantssystem was studied through copolymerization under continuous microwave oven and domestic microwave oven. The results showed thattemperature of reactants system evolved smoothly without step under continuous microwave iradiation, which occurred under intermit-tent microwave iradiation in domestic microwave oven.Key words: continuous microwave imadiation; polylactide; poly ( ethylene glycol) ; copolymerCLC number: TQ316. 6*1Document code; AArticle ID: 0529-6579 (2007) SI 0130-03Poly (D, L-lactide) -co-poly ( ethylene glycol)(Sn (Oct)2) was used as catalyst. PEG1000 and tet-( PELA), obtained through copolymerizing PEG intorahydrofuran (THF) were analytically pure.Poly (lactie acid) (PLA) chains, has not only the.2 Procedureproperties of PLA homopolymery , but also hydrophilici-3g DLLA and PEG - 1000 in a certain proportionty, toughness，flexibility and so on which are not avail-were weighed into a 50mL beaker, Sn( 0ct)2(0. 40% )able in PLA homopolymery'.as catalyst then the beaker was placed on the heating-Microwave technology for organic synthesis reac-medium and was irradiated under microwave power oftion has been reported[2-3]Nowadays most research 90W for minutes.of organic synthesis reaction are still concentrated 0.3 Measurementsthe domestic microwave ovens'”. Because microwaveIntrinsic viscosity of PELA was measured with anis intermittently irradiated, reaction temperature rises atUbbelohde viscometer in THF at 379C. IR spectrahe presence of microwave irradiation and drops at the , were recorded on a Nicolet - 670FT-IR apparatus.' Habsence of it during reaction. Such a heating way is ad-NMR spectra of polymer were recorded with a Brukerverse to reaction. Moreover, power adjustment of do-AC-P200MHz apparatus.mestic microwave oven is limited for several intervalsand can't meet the actual requirement. In this paper ,2 Results and discussioncontinuous microwave oven was used ( 2450MHz)，2.1 Effect of PEG contentpower output of which was continuous without intermit-In the Fig 1, when PEG content was 1%，PELAtence and overcome the shortcomings of domestic micro-with maximum intrinsic viscosity of 0.51dL●g~' waswave imadiation.synthesized. It was considered that with PEG content1 Experimentalincreasing, chain transfer rate increased, which resul-ted in the halt of the chain growing, thus lowered co-1.1 Materialspolymer viscosity.The synthesis and purification of D, L-lactictide(DLLA) was according to ref [5]. Stannous octoate中国煤化工MHCNMHG收稿日期: 200701-10基金项目:哈尔滨市科技攻关资助项目(2005AA4CS112)作者简介:张英民(1976年生)，男，博士生;通讯联系人:王鹏; E mail: pwang73@ hit edu. en增刊张英民等:常压连续微波辐射法合成聚乳酸-聚乙二醇共聚物1310.8厂丁10025080200.6 |Inermillent microwave(t50W)150 1Continuous mircrowave(90W).4--0- Yield1000.2个-205(00724681012140 35PEG content/%Polymerizaion time/minFig 1 Effect of PEG contentFig 3 Evolving of temperature of reactants system2.2 Effect of microwave-irradiated timeFig 2 shows that when polymerization time was 3 Conclusionsless than 8 minutes, the temperature was not high e-(1) PELA was synthesized at atmospheric pres-nough and polymerization was not sufficient. The prod-uct had rlatively low viscosity. But with polymerizaion sure without vacum and inert gas under continuous mi-time increasing, reactants temperature gradually rose crowave iradiation. This technique was suitable forand the copolymer viscosity increased. When time more large-scale preparation of PELA.than 8 minutes , reactants began to overheat and copoly-(2) In 8 minutes PELA of 0.5dL●g' intrinsicmer began to pyrolysis.viscosity was obtained under 90W power continuous mi-crowave iradiation. Under optimum conditions, the0.25t8yield was about 85% .(3) Reactants system temperature increased faster”0.2t6and had no step under continuous microwave iradia-40占0.15{ ◆tion. But intermittent microwave radiation in domestict20.10microwave ovendid the opposite.5678910References:Reaction time/min[1] DENG C, RONG C z, TIAN H Y, et al. Synthesis andFig2 Elect of microwave-irradiated timecharaceriaion of poly ( ethylene gycol) -b-poly (Llactide) -b-poly ( Lglutamie acid) triblock copolymer2.3 Temperature rising behavior in reactants[J]. Polymer, 2005, 46: 653 - 659system[2] MAURO I, HELMUT R. Microwave asted direct syn-Fig.3 shows that temperature of reactants systemthesis and polymerization of chiral acrylamide [ J].rose rapidly under continuous microwave irradiation,Macromol Chem Phys, 2005, 206: 349 -353.then kept relatively steady. It was worth to noting that[3] MURAT C, SULEYMAN s. Microwave asited from ;temperature of reactants system evolved smoothly with-synthesis of 2-arylamino-2-imidazolines on a solid sup-out step. However ，under intermittent microwave radia-port [J]. Heteroatom Chem, 2005, 16 (2): 142 -tion in domestic microwave oven, temperature of react-147ants system rose in the presence of microwave irradia-[4] LIUFP, LU M. Recent development of microwave or-tion, fell in absence of microwave irradiation, so localganic synthesis and reaction -oriented special microwavetemperature change behaved step. So the whole evol-equipment [ J]. Liaoning Chemical Industry, 2004,ing tend of temperature of reactants system took an in-33 (2): 92 -95.creasing look, but it was clear to find local temperature [5] ZHANG K, WANGP, U W K, et al. Synthesize processstep, which led to the ununiformity of temperaturediation [J]. Polymerfield, affected the polymerization process seriously.中国煤化工004, 20(3): 46-fYHECNMHG.(下转第138页)38中山大学学报( 自然科学版)第46卷[6] National Environmental Protection Agency. AnalyticalChinese) [M]. Beiing: Publishing House of ChinaMethods of Water and Wastewater, 4th edition, ( inEnvironmental Science, 2002: 368 - 371.超滤膜去除地下水中硝基苯的试验研究赵玉鑫'，尹军'，王晓玲'，刘蕾(1. 哈尔滨工业大学市政环境工程学院，黑龙江哈尔滨150090;2.吉林建筑工程学院环境工程系，吉林长春130021)摘要: 为解决持久性有机污染物对地下水造成的污染，以硝基苯为研究对象，考察了超滤膜对硝基苯的去除效果及影响因素。试验结果表明，当进水硝基苯浓度为85 ug/L,超滤膜可以连续工作68 h,出水小于17 ug/L。地下水中铁、锰离子对去除效果没有显著影响。进水硝基苯浓度对去除效果有显著影响。当进水硝基苯浓度由85 ug/L上升至340 ug/L时，超滤膜连续工作时间急剧下降，仅为14 h;对由硝基苯引起的膜污染，2% CH,CH,OH 清洗效果最佳。作为-项应急处理技术，该工艺可以保障小城镇地区饮水安全。关键词:地下水;持久性有机污染物;超滤;硝基苯中图分类号: X523(上接第131页)常压连续微波辐射法合成聚乳酸-聚乙二醇共聚物张英民，王鹏"，李悦，雷海芬，焦春艳，韩宁(哈尔滨工业大学市政环境工程学院绿色化学与技术研究中心，黑龙江哈尔滨150090)摘要: 常压条件下、连续微波辐射功率90w,辐射时间8min, 合成了特性粘度为0.51 dL.g"'的聚乳酸-聚乙二醇共聚物(PELA)。 考察了聚乙二醇(PEG)浓度、聚合时间对共聚物特性粘度和收率的影响。此外，实验研究了连续微波炉与家用微波炉中反应体系的温升曲线。结果显示，相比于家用微波炉中的间歇微波辐射,连续微波辐射下反应体系温度上升平稳无突跃。关键词:连续微波辐射;聚乳酸;聚乙二醇;共聚物中图分类号: TQ316.6*1中国煤化工MYHCNMHG