常壓連續微波輻射法合成聚乳酸-聚乙二醇共聚物

第46卷增刊中山大學(xué)學(xué)報( 自然科學(xué)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中國煤化工MHCNMHG收稿日期: 200701-10基金項目:哈爾濱市科技攻關(guān)資助項目(2005AA4CS112)作者簡(jiǎn)介:張英民(1976年生)，男，博士生;通訊聯(lián)系人:王鵬; E mail: pwang73@ hit edu. en增刊張英民等:常壓連續微波輻射法合成聚乳酸-聚乙二醇共聚物1310.8廠(chǎng)丁10025080200.6 |Inermillent microwave(t50W)150 1Continuous mircrowave(90W).4--0- Yield1000.2個(gè)-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.中國煤化工004, 20(3): 46-fYHECNMHG.(下轉第138頁(yè))38中山大學(xué)學(xué)報( 自然科學(xué)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.超濾膜去除地下水中硝基苯的試驗研究趙玉鑫'，尹軍'，王曉玲'，劉蕾(1. 哈爾濱工業(yè)大學(xué)市政環(huán)境工程學(xué)院，黑龍江哈爾濱150090;2.吉林建筑工程學(xué)院環(huán)境工程系，吉林長(cháng)春130021)摘要: 為解決持久性有機污染物對地下水造成的污染，以硝基苯為研究對象，考察了超濾膜對硝基苯的去除效果及影響因素。試驗結果表明，當進(jìn)水硝基苯濃度為85 ug/L,超濾膜可以連續工作68 h,出水小于17 ug/L。地下水中鐵、錳離子對去除效果沒(méi)有顯著(zhù)影響。進(jìn)水硝基苯濃度對去除效果有顯著(zhù)影響。當進(jìn)水硝基苯濃度由85 ug/L上升至340 ug/L時(shí)，超濾膜連續工作時(shí)間急劇下降，僅為14 h;對由硝基苯引起的膜污染，2% CH,CH,OH 清洗效果最佳。作為-項應急處理技術(shù)，該工藝可以保障小城鎮地區飲水安全。關(guān)鍵詞:地下水;持久性有機污染物;超濾;硝基苯中圖分類(lèi)號: X523(上接第131頁(yè))常壓連續微波輻射法合成聚乳酸-聚乙二醇共聚物張英民，王鵬"，李?lèi)?，雷海芬，焦春艷，韓寧(哈爾濱工業(yè)大學(xué)市政環(huán)境工程學(xué)院綠色化學(xué)與技術(shù)研究中心，黑龍江哈爾濱150090)摘要: 常壓條件下、連續微波輻射功率90w,輻射時(shí)間8min, 合成了特性粘度為0.51 dL.g"'的聚乳酸-聚乙二醇共聚物(PELA)。 考察了聚乙二醇(PEG)濃度、聚合時(shí)間對共聚物特性粘度和收率的影響。此外，實(shí)驗研究了連續微波爐與家用微波爐中反應體系的溫升曲線(xiàn)。結果顯示，相比于家用微波爐中的間歇微波輻射,連續微波輻射下反應體系溫度上升平穩無(wú)突躍。關(guān)鍵詞:連續微波輻射;聚乳酸;聚乙二醇;共聚物中圖分類(lèi)號: TQ316.6*1中國煤化工MYHCNMHG