3D打印材料范文

3D3D打印材料范文打印材料范文 Materials and Design102 xx 276 283Contents listsavailable atScienceDirect Materials andDesignjournal homepage elsevier locate matdes Mechanicaland thermal properties of ABS montmorillonite nanopositesfor fused deposition modeling3D printingZixiang Wenga c Jianlei Wanga c T Senthil a Lixin Wua b a Key Laboratory of Design and Assembly of Functional Nanostructures Fujian Instituteof Researchon theStructure ofMatter Chinese Academyof Sciences Fuzhou350002 China bFujian ProvincialKey Laboratoryof Nanomaterials Fujian Instituteof Researchon theStructure ofMatter Chinese Academyof Sciences Fuzhou350002 China cUniversity ofChinese Academyof Sciences Beijing100049 China ar ti cl ei nf oArticle history Received25FebruaryxxReceived inrevised form11AprilxxAepted14AprilxxAvailable online16AprilxxKeywords ABS MontmorilloniteFused deposition modeling Nanoposites3D printingRapid prototypinga bs tr ac tAcrylonitrile butadienestyrene ABS nanoposites withorganic modifiedmontmorillonite OMMT were prepared by melt intercalation ABS nanoposite filaments for fused deposition modeling FDM 3D printingwere producedby asingle screw extruder andprinted by a mercialFDM3D printer The3D printedsamples were evaluated bytensile flexural thermal expansion and dynamicmechanical tests The structure of nano posites wereanalyzed by TEM andlow angle XRD Results showedthat the addition of5wt OMMT improvedthe tensile strength of3D printedABS samplesby43 while the tensile strength of injection moulding ABSsam ples were improved by28 9 It wasfound that the addition of OMMTsignificantly increasedthe tensilemodulus flexural strength flexural modulus and dynamicmechanical storage modulus and decreasedthe linearthermalexpansion ratioand theweight lossof TGA These novel ABS nanoposites with bettermechanical and thermal propertiescan be promising materialsused inFDM3D printing xxElsevier Ltd All rightsreserved 1 Introduction Three dimensional 3D printing isone of the mostversatile andrevolutionary additivemanufacturing AM techniques tocreate3D ob jects withunique structureand diverseproperties 1 Presently various techniquessuch asfused deposition modeling FDM 2 stereolithography apparatus SLA 3 continuous liquidinterface pro duction CLIP 4 digital lightprocessing DLP 5 and selectivelaser sintering SLS 6 have beendeveloped toform stereoscopicobjects withplex architecture In thelate1980s S Scott Crumpdeveloped FDM3D printerand itwas mercializedby Stratasysin1990 7 Now FDM hasbee themost widelyused3D printingmethod dueto itssimple to use low cost andenvironment friendly featuresand isincreasingly used in productdevelopment prototyping andmanufacturing processesin avariety ofindustries including householdappliances automobile toys architecture medical appliances aircraft andaerospace However the followingslimit theapplication ofFDM3D printing the mechanical strength of the FDM printed productsare usuallyworse paredwith injection moulding dueto theirweakness pointsbetween thelayers 8 and also the thermoplastic materials tendto Correspondingauthor at KeyLaboratoryofDesignandAssemblyofFunctionalNanostructur es Fujian Instituteof Researchon theStructure ofMatter Chinese Academyof Sciences Fuzhou350002 China E mail address lxwu fjirsm ac L Wu shrink during the coolingprocess resulting inwarp of the printedprod ucts 9 To date the FDM3D printinghas beenstudied in the fieldsof buildingequipments materials 10 preparation techniques 11 and numericalsimulation 12 and attractedmore andmore interests Usually thermoplasticmaterialslike ABS 13 14 nylon 7 15 polylactic acid PLA 16 and theirblends 17 are used for FDM3D printer To enhance the mechanical properties of3D printedthermo plastics fiber reinforced positeswere used However addition offi bers oftenresult inthat theposites aresusceptible tofracture duringextrusion Special additivesmay benecessary in the extrusionto helpproduce continuousand homogeneousfilaments 18 In recentyears the emergenceof nanopositeshas attractedgreat interestamongst researchers By usingsmall volumefractions of nano additives mechanical properties 19 20 heat distortiontempera ture 21 22 and thermal stability 23 24 of apolymer matrix can beim proved Thereinto polymer layered silicate PLS nanoposites showedsignificant improvement in theproperties of polymer matrix Numerous studiesreported thePLS nanopositesexhibited bettermechanical property including dynamicmechanical 25 tensile 26 and flexuralproperties 21 than thatof polymermatrix Wang et al 27 studiedthe thermal properties of ABS montmorillonite nano posite They observedthat theintercalated exfoliated structure was ob tained and the thermalstability of ABS wasimproved byonly5wt of organ montmorillonite Lately Yeh et al 28 studied the tensile strength of ABS organoclay nanoposites and found that the tensile strengthcan beimproved15 by adding3wt of organoclay only dx doi 10 1016 j matdes xx 04 0450264 1275 xxElsevier Ltd All rightsreserved Z Weng et al Materials andDesign102 xx 276 283277Fig 1 Chemical structure of HDBAC Nowadays various nanoreinforcementshave beenused in3D printedmaterials including nanocrystallinecellulose NCC 29 SiO2 30 31 andlayered silicate 32 33 However most of them wereSLA3D printedmaterials FDM3D printednanoposites havenot beenfully studied In thiswork FDM3D printednanoposites were pre pared ABS nanopositesamples wereprinted by a mercialFDM3D printer The mechanical properties of3D printednanopos ites samples wereevaluatedand pared to thoseof injectionmould ing samples The thermal properties of ABS nanopositeswere alsostudied It wasfoundthat the polymernanoposites couldbeprom ising highperformance FDM3D printedmaterials 2 Experimental2 1 Materials Thepristine montmorillonite was purchasedfrom Nanocor trade nameas PGW its CECis145 10 meq 100g Organic modifier benzyldimethylhexadecylammonium chloride HDBAC was boughtfrom AladdinIndustrial Inc China The chemicalstructure of HDBAC is shown in Fig 1 ABS pellets trade nameas PA 705 was suppliedby QimeiStock Company China 2 2 Modification ofpristine clayAording toPinnavaia s 34 35 method 10g ofpristine claywas dispersedinto500mL ofdistilled waterat60 C andsuspension wasob tained Stoichiometric ratio ofHDBACwere addedto the suspension andstirred for5h Followed bythat thesuspensionwas cooledat room temperature and then pouredinto apressure filtrationdevice By pres sure filtrationand washedseveral timeswith distilledwater untilno chloridewas detectedby0 1M AgClsolution the filtercake wasob tained In orderto preventagglomeration the filtercake wasdried by a freezedrier andfine powderof organicmontmorillonite OMMT was obtained 2 3 Preparation of ABS OMMT nanopositeFirst ABS pelletsand different amount of OMMT powder 1wt 3wt 5wt of ABS pellets denoted byABS 1 ABS 3and ABS 5 respec tively were physicallymixed by a homogenizer After that the mixtureof ABS and OMMT were meltmixed usinga twin screw extruder Haake RheomexOS Thermo Fisher Germany The temperature of6heating chambersare200 C 210 C 220 C 220 C 210 C 200 C fromfunnel toextrusion headrespectively The twin screw extruderused inthis studyis schematizedin Fig 2 The extrusionspeed was50rpm After ex trusion the filament of the ABS OMMT nanopositewere cutinto pelletswith apelletizer and then theywere driedin anoven at60 C for4h toget ridof moisture 2 4 Preparation offilament forFDM3D printerAfter desiation the pelletsof ABS OMMT nanopositewere pouredinto asingle screw extruder SJ 30 25 Zhangjiagang GrandFig 2 General viewof twinscrew extruder 278Z Weng et al Materials andDesign102 xx 276 283of thedie is3mm The single screw extruderis shown in Fig 3 By adjustingthe rotatingspeed ofwinder OMMT reinforcedABS nano posite filamentswith diameterof1 75mm 0 1mm wereob tained In orderto offsetthe influenceon propertiescaused bymixing andextrusion the pure ABS pelletswere also remixed bytwinscrewex truder andsinglescrewextruder 2 5 Sample preparationSpecimens formechanical studiesof3D printedsamples includingtensile strength and flexural strength weredesigned aording to ASTMD790 03and ASTMD638 03 respectively Also the samplesused forlinear thermo expansion ratiotest andDMA testwere alsomade by FDM3D printer Creator Flashforge China aordingtotest Fig 3 General viewof singlescrewextruderused in the production of the ABS OMMTnanoposites filament Fig 4 FDM3D printerused inthis study Machinery Co Ltd China The temperature of atwo heatingchambers was200and210 C respectively and thetemperature ofextrusion headwas190 C The rotationspeed of the screwis500rpm andthe diameterFig 5 Low angleX ray diffractionspectra of ABS OMMT nanoposites Fig 6 Transmission electronmicroscopy micrographsof ABS OMMT nanoposites Z Weng et al Materials andDesign102 xx 276 283279Table1Mechanical properties of ABS nanoposites Samples TensileTensile RatioElastic Elasticstrength strength injection printed modulus modulus injection printed injection printed Control49 94 27 591 811 91 2ABS 155 4331 491 762 61 4ABS 358 6336 331 6132 8ABS 564 3639 481 633 23 6requirements The FDM3D printerusedinthis paperwas shownin Fig 4 All the specimens areprinted directlyon theheating platewith out anysupports The fillingrate of thespecimens were setto100 which meansthat theall specimensare solidstructure Furthermore tensile strengthspecimens usingan injectionmould ing aremade by a HaakeMiniJet Thermo Fisher Germany to parethe disparitybetween injection moulding and3D printing The temper atureof the injectionmoulding furnaceand diewas210 C and50 C respectively andthe injection pressurewas800bar 2 6 Characterization ofnanoposites X ray diffraction XRD and transmissionelectron microscope TEM were usedto examihe microstructureand dispersionmorphology ofthe nanoposites The XRDpatterns ofthe sam ples were obtained usingCo K radiation l 1 78901 in anX Pert ProMPD Philips Netherlands diffractometer operatingat40kV and30mA 2 range from1 to10 with astep sizeof0 02 Microstructural characterizationofthe nanoposites was carried outusing JEM xx JEOL Japan at anaeleration voltageof200kV The samplesused forTEM wereprepared bya cryo ul tramicrotome EM UC7 Leica German Tensile strength and flex ural strength of different samples werecarried outbyauniversal materialtest machine AGX 100PLUS Shimadzu Japan The strainwas obtainedbyanon contact extensionmeter The analysisspeed ofthe tensile strengthand flexural strengthwas5mm min and2mm min respectively The storage modulus of ABS OMMT nanopositeswas carried out withDMA Q800 TA USA at aheating rateof5 C min andthe testmode wassingle cantilever Frequency andamplitude were1Hz and20 m respectively The linear thermo expansion ratio of materials werecarriedoutonathermal dilatometer DIL402C Netzsch Germany The initiallength ofspecimenswere25mm andthe analysistemperature rangestarted from25to80 C Thermogravimetric analysiswas carriedout withSTA449C Netzsch Germany in therange from25to800 C underan airatmosphere The glass transition temperaturewas obtainedbya differential scanning calorimetry DSC822e Mettler Toledo Switzerland in therange of50to160 C undera nitrogenatmosphere Fig 7 Tensile strength a and elastic modulus b of ABS OMMT nanopositesFig 8 Tensile strength a and elastic modulus b of ABS OMMT nanopositessamples made by injectionmoulding samples madebyFDM3D printer 280Z Weng et al Materials andDesign102 xx 276 283Fig 9 Illustration offracture sectionof printedsamples 3 Results anddiscussion3 1 Clay dispersionand morphologyLow angleX ray diffraction XRD was usedto determihe micro structure ofthe clay and its nanoposites The XRDpatterns ofpris tine montmorillonite OMMT and itsnanoposites are shownin Fig 5 For pristinemontmorillonite a diffraction peak around8 1 wasobserved indicating ad spacing of1 27nm As forOMMT an obviousdiffractionpeakat4 4 was observed corresponding to ad spacing of2 3nm This observationindicated that the pristinemontmorillonitewasmodified byorganic modifier As expected the diffractionpeak ofthe nanopositeswas shiftedto alower degree andtheintensity in creased withincreasing content ofthe OMMT The peaksof ABS 1 ABS 3and ABS 5were observedat2 8 3 7nm 3 0 3 4nm and3 2 3 2nm respecti vely This wasbecause somelarge intercalatedtactoids stillcan beidentified in ABS matrix This similarobservation re sults can be foundin numerousliteratures 28 36 The distributionofthe clayandmorphologies ofthe nanopositeswere examinedbyTEM The representativeTEM micrographsofnano positeswithdifferent amountof montmorilloniteare shownin Fig 6 The darklines whichrepresents theplate of organoclay weredis tributed intheABS matrix andan intercalatedstructurewasformed inthenanoposites As evidencedfrom theseimage the interlayerspacing was about3 5nm Even whentheclay content increased to5wt theABSmatrix can also intercalateinto thegallery ofthe mont morillonite These results were identicalto theXRD results At thesame time the OMMTinthematrix exhibitcertain orientation It canbe ex plained that the montmorillonitewas reorientedby the extrusion andwinder duringtheextrusionprocess 3 2 Mechanical propertiesTensile strengthand elasticmodulus ofspecimens prepared by in jectionmoulding are listedin Table1and shownin Fig 7 Both theten silestrengthandthe elasticmodulus increased substantiallywith theadditionof OMMT content When theclay loadingwas5wt thetensilestrength increased from49 64MPa control to64 36MPa andtheelas ticmodulusincreased from1 9GPa control to3 2GPa Simultaneously theelongation atbreak of different samplesdecreased with the increase of OMMTloading It canbe explained thatthe OMMT hasmuch higher modulusand strength thanABS resulting inhighermodulusandstrengthof ABS OMMT nanopositesparedtopure ABS More over the well dispersed OMMT can restrictthe mobilityof ABSmolecular chains resulting inhigher stiffnessand lesselongation ofnanoposites Similar trendand experimentalresultswerealsore ported byreferences 37 39 Fig 10 Flexural strength a andflexural modulus b of ABS OMMT nanopositessamplesmadebyFDM3D printer Z Weng etal Materials andDesign102 xx 276 283281Fig 11 The curves of storage modulus responsesto temperaturefor thepure ABSand ABS OMMT nanoposites Fig 13 Thermal expansion coefficient ofpure ABSand ABS OMMT nanoposites Tensile strengthand elasticmodulus ofspecimens prepared by3D printerare listedin Table1and shownin Fig 8 By introducing5wt loading of OMMT thetensilestrengthofFDM3D printedsamples in creased from27 59MPa control to39 48MPa the elasticmodulusin creased from1 2GPa control to3 6GPa The ABS OMMT nanopositeprepared byusing injectionmoulding methodshowed highertensilestrengthas paredto theFDMprintedones This ismainly dueto1 duringtheFDM3D printingprocess the moltenfila ment is attached onthe surfaceof solidlayer resulting inpoor entangle mentof polymer molecular 2 as shownin Fig 9 the arrangementof roundand ovalfilaments inFDM processcannot avoidthe gapsbe tween filaments 40 resulting invoids inprinted objects and thenre duce the mechanical properties 3 the highpressure intheinjectionmoulding processcan promotethe entanglementof polymerchains andincrease thedensity resulting bettermechanical properties How ever by introducing OMMT the disparityof tensilestrength betweenFDM and injectionmouldingare narrowed This positiveeffect canbe contributedby theorientation of OMMT During theFDM3D printing theOMMTwere orientatedalong thedirection ofextrusion while theOMMTwererandomly arrangedduring injectionmoulding The orien tated OMMThave betterreinforced effectalong thefilament direction Also the flexuralstrengthofFDM3D printedsamples weretested andisshownin Fig 10 Similar to thetensileproperties the flexuralstrengthandflexuralmodulusincreases withincreasing contentof OMMT Such phenomenoncanalsobe explainedby thetoughening ef fects broughtby theOMMT Fig 10illustrates thatthe increasein flex uralstrengthfrom42 69MPa control to56 92MPa areachieved at5wt loading of OMMT These dataindicate thatOMMTcanimprove themechanical properties ofABSas FDM3D printedmaterials Dynamic mechanicalanalysis DMA was carriedout tomeasure the storagemodulus ofABSanditsnanoposites The storagemodulus curvesofthepureABSand ABS nanopositesareshowninFig 11 By incorporationwell dispersed OMMT a remarkablyincreased ofstor agemoduluscanbeachieved with the increase of OMMTloading At25 C the storagemodulus of neat ABSwas1 1GPa whereas beyond3wt of OMMTcontent e g 5wt resulted in1 6GPa increaseinthestoragemodulus In the glassy state thestoragemodulusoforganoclay nanopositesare higherthan neat ABS this indicatesthat intercalated exfoliated mixedstructureofABS organoclay nano posites canenhancethemechanical properties ofthematerials 3 3 Thermal propertiesFor FDM3D printing the linear expansion ratioof materialsisacrit ical factorto affectthe dimensionof products As showninFig 12 for thepolymer whichhas lowerlinear thermoexpansion ratio the volumeofthematerials didnot changetoo muchwiththechange oftempera ture resulting inless orno warping and deformation of printedsamples whencooled toroomtemperatureduring FDM3D printing On theother hand neat ABSsamples oftenshow warpingafter FDM3D print ing dueto itshigh linearthermoexpansion ratio When arelative largeABS objectis printedbyaFDM3D printer such shrinkagecan leada de lamination betweenlayers leadingtoafailure ofprinting In thisstudy the linearexpansion ratioof neatABSand ABS OMMT nanopositeswere examinedfrom roomtemperature to80 C Fig 13and Table2show the linearexpansionratioofdifferent samples It canbe seenthatthe linearthermoexpansionratiodecreases withincreasing con tentofOMMT As reportedin Ref 41 theOMMTplayed asthe hardFig 12 Illustration ofmaterials warpingand deformationin differenttemperature zone 282Z Weng etal Materials andDesign102 xx 276 283Table2Linear expansioncoefficient ofdifferentsamples Samples LinearexpansioncoefficientControl9 82 10 5 C 1ABS 18 93 10 5 C 1ABS 37 61 10 5 C 1ABS 56 27 10 5 C 1segment whichcan restrictthe movementofpolymerchain and lowerthe linearshrinkage ratio Therefore theadditionofOMMTinABSma trixcanreduce