塑木发泡复合材料

PVC塑木发泡

复合材料

PVCwood-plastic-foamedcomposites四川大学高分子科学与工程学院CollegeofPolymerScienceandEngineering,SichuanUniversity黄锐HUANGRui

2010年9月塑木复合材料的优点

TheAdvantagesofWPC1

23PVC塑木发泡复合材料PVCWood-plastic-foamedComposites4

塑木复合材料成型设备及工艺MoldingEquipmentandTechnology

ofWPC5发展塑木复合材料的意义TheSignificanceofDevelopingWPC

国内外塑木复合材料发展现状ThePresentDevelopmentofWPCHomeandAbroad概要Summary

塑木复合材料(wood-plasticscomposites,WPC)是木质材料与热塑性塑料或热固性塑料复合而成。其中木质材料包括木屑、刨花、竹屑、麦秸、谷糠、椰子壳、甘蔗渣、花生壳、大麻等。WPC(wood-plasticscomposites)ismadeofwoodmaterialsandthermoplasticorthermosettingplastic.AmongwoodmaterialsincludeSawdust,woodshavings,bambooshavings,straw,chaff,coconutshells,bagasse,peanutshells,hemp

etc.

木粉WoodFlour

谷糠Chaff秸秆纤维StrawFiber塑木复合材料Wood-plasticsComposites与木材相比：具有优良的物理化学特性。容易清洗。制品能回收再利用，也可生物降解，环境友好。可加入着色剂、抗菌剂、发泡剂等，赋予其需要的功能。使用寿命长，维护成本低。具有塑料的成型加工性，易加工，可挤出、注塑、压制成型各种尺寸、形状制品Comparedwiththewood:

Excellentphysicalandchemicalproperties.

Easytoclean.

Productscanberecycled,andbiodegradable,environmentallyfriendly.

Canbeaddedcoloringagents,antibacterialagents,foamingagents,etc.,endowedwithfunctionswhichareneed.

Longservicelife,lowmaintenancecost.

Withplasticmolding,easyprocessing,canbeextrusion,injectionmolding,pressingavarietyofsizes,shapesproducts.

一、塑木复合材料的优点：

TheAdvantagesofWPC

与塑料相比：Comparedwiththeplastic:（1）具有类似木材的二次加工性，可锯、可刨、可粘接、可用钉子或螺钉固定，容易维修。Secondaryprocessinglikewood,canbesawed,planed,bonded,cannailorscrew,easytomaintain.

（2）原料来源广、制品成本低于同类塑料制品。Awidesourceofrawmaterials,costlessthansimilarplasticproducts.（3）类似天然木质的外观和手感。Similarlookandfeelofnaturalwood.

（4）尺寸稳定性，硬度比塑料好。Dimensionalstabilityandrigiditybetterthanplastic.

WPC综合了塑料与木材两种材料的性能特点，具有非常广泛的用途。WPCsynthesizetheperformancecharacteristics

ofplasticandwoodwithaverywiderangeofuses.

减轻环境污染ReduceEnvironmentalPollution有效缓解木材资源紧缺的现状Effectivelyalleviatetheshortageoftimberresources促进资源的综合利用和循环经济的发展。Promotethecomprehensiveutilizationofresourcesandthedevelopmentofrecycleeconomy.二、大力发展塑木复合材料的意义：

TheSignificanceofDevelopingWPC主要应用领域包括：Mainapplications:(1)建筑和装饰行业Construction&Decoration(2)园林方面Gardening(3)市政建设MunicipalBuilding(4)汽车业Automotive(5)物流方面Logistics塑木复合材料的应用：TheApplicationofWPC(1)建筑和装饰行业Construction&Decoration

(1)建筑和装饰行业Construction&Decoration

(1)建筑和装饰行业Construction&Decoration

（2）园林方面Gardening（2）园林方面Gardening（2）园林方面Gardening（2）园林方面Gardening（2）园林方面Gardening（2）园林方面Gardening（3）市政建设MunicipalBuilding

(4)汽车业Automotive（5）物流方面Logistics

据PrincipiaPartners咨询公司专题报告，北美WPC需求约占世界总量的85％，2001年400kt，2006年1000kt，产值超过10亿美元，年增长超过25%。2007年北美WPC年需求总量已超过700kt，预计2010年将达1600kt。

AccordingtoconsultingcompanyPrincipiaPartnersspecialreport,NorthAmericandemandforWPCabout85%oftheworldtotal,thereare400ktin2001,1000ktin2006.Theoutputvalueismorethan1billionU.S.dollars,annualgrowthrateismorethan25%.TheannualtotaldemandingquantityofWPCinNorthAmericain2007isover700kt.Itwillbeexpectedtoreach160ktby2010.三、国内外塑木复合材料发展现状ThePresentDevelopmentofWPCHomeandAbroad2006年底统计表明，美国有101家WPC加工厂，加拿大11家。WPC原料树脂中PE、PP和PVC分别占75％、12％和10%。塑木铺板占总铺板（70万吨）中的一半，其次为窗框系统，约7万吨，包括铺板、门窗框系统的挤出型材和屋面板、墙面板。Statisticsshowthatbytheendof2006,thereare101WPCprocessingplantsintheUnitedStates,11onesinCanada.PE,PPandPVCrespectivelyaccountedfor75%,12%and10%ofWPCresinrawmaterials.Wood-Plasticplankoccupyhalfofthetotal(700,000tons),followedbywindowframesystem,about70,000tons,includingtheplank,doorframesofextrusionsystems,roofprofileandwallpanels.三、国内外塑木复合材料发展现状ThePresentDevelopmentofWPCHomeandAbroad欧洲Europe

2009年欧洲生产厂家已达61家，其中德国19家，英国7家，瑞典6家，芬兰、奥地利各5家。欧洲WPC用基础树脂与美国结构不同，欧洲只有为数不多的厂家使用PVC为基材，大部分是PP基材料，PP占82％，PE10％，PVC8％。In2009,Europeanmanufacturershavereached61,including19inGermany,7inUnitedKingdom,6inSweden,5inFinland,5inAustria.TheWPCbasedresinusedinEuropehasthedifferentstructuresfromtheUnitedStates,onlyafewEuropeanmanufacturersusePVCforthesubstrate,mostarePP-basedmaterials,includingPPaccountedfor82%,PEaccountedfor10%,PVCaccountedfor8%.亚洲（除中国）Asia(excludingChina)

亚洲WPC开发比较成熟的主要是日本。日本由于地理和环保意识等原因，塑木材料的应用比较普遍。虽然日本塑木复合材料发展较成熟，从1992年开始也较早的进行了商品化，但制品发展仍然缓慢。除日本外，印度近年用量也有较大增加，亚洲其它国家的生产、应用都相对较少。AsianWPChasdevelopedmorematurelyinJapanthanothers.Duetogeographicalandenvironmentalawarenessandotherreasons,theapplicationofWPCmaterialsisrathercommon.AlthoughtheJapanesewoodcompositehasdevelopedmorematurely,andsince1992ithasearlierbeencommercialized,theproductdevelopedstillslow.ExceptJapan,Indiahasalargeamountofincreaseinrecentyears,butintheotherAsiancountries,theproductionandapplicationsarerelativelyless.

我国塑木行业在国家政策的鼓励和企业潜在效益驱动下，发展迅猛。截止2009年底，全国直接从事塑木材料研发、生产的企事业单位超过200家，塑木制品年产量约10万吨，年产值约12亿人民币。各种类的WPC比例见下图，可见我国WPC中，PE和PVC约各占一半。Ourplasticwoodindustryencouragedbythenationalpolicyanddrivenbypotentialbenefits,developsrapidly.Bytheendof2009,therearemorethan200enterprises

whicharedirectlyengagedinresearchandproduction

inthewholecountry.Theannualoutputofplasticwoodproductisabout10milliontonsannualproductionvalueisabout1.2billionyuan.TheproportionofdifferenttypesofWPCshownbelow,itcanbeseenthatPEandPVCishalfeach.我国塑木产品市场的一些情况SomecasesaboutmarketsinChina塑木行业现状ThePresentSituationintheFieldofWPC发泡的意义

TheSignificanceofFoaming为了节省资源，减少塑料废弃物对环境的危害，塑料制品轻量化（发泡）是发展趋势。Inordertosaveresourcesandreduceenvironmentalhazardsofplasticwaste,plastictolightweight(foaming)isthetrend.

微孔发泡能够显著提高材料的抗冲击强度、韧性、疲劳周期、热稳定性等。Microcellularfoam

cansignificantlyimproveimpactstrength,toughness,fatiguecycles,thermalstabilityetc.目前，我国的发泡加工成型已形成相当规模的生产能力。Atpresent,thefoammoldingprocesshasafairlylargescaleproductioncapacity.

目前发泡WPC占WPC总量的20%左右，其比例还可能会增加，其中大部分是PVC和PE基。PVC基的塑木复合物的密度通常为1.3g/cm3左右，发泡后可使密度降至0.6g/cm3，具有更好的经济性。CurrentlyWPCfoamaccountsfor20%aboutofthetotalofWPC,theproportionmayincrease,andmostofwhichisPVCandPE-based.ThedensityofPVC-baseWPCmaterialisusuallyabout1.3g/cm3,afterfoamingthedensitywillfallto0.6g/cm3,withabettereconomy.

四、PVC塑木发泡复合材料PVCwood-plastic-foamedcomposites

PVC发泡原理和过程

PrincipleandProcessofPVCFoamingPVC发泡包括物理发泡和化学发泡两种。PVCfoamingincludingphysicalandchemicalfoaming.物理发泡法是用低沸点的物质作发泡剂，靠加热或减压挥发产生的气体进行发泡。Physicalfoamingistousethelow-boilingmaterialasfoamingagent,itfoamsbyheatingorpressiontovolatilizegases.

化学发泡法是利用化学物质加热时分解或反应产生气体来使PVC发泡。ChemicalfoamingistomakePVCfoambythegaseswhenthechemicalisheatedandposedorreact.工业上PVC发泡材料多采用化学发泡方法。InIndustryPVCfoammaterialmostadoptchemicalfoamingmethod.PVC发泡材料的成型方法PVC主要分为：PVCFoamingisDivided:注塑发泡成型InjectionFoaming挤出发泡成型ExtrusionFoaming模压发泡成型MoldFoamingMoldingMethodsofPVCFoaming

PVC塑木复合材料挤出发泡的原料，PVC分子量选择非常重要，它将改变复合物的流变性，从而对气泡的生长影响很大。分子量过低，熔体强度较差，对发泡气体逃逸的阻碍能力差，很难得到泡孔均匀细密的泡沫塑料。分子量过高，熔体的拉伸强度很大，抑制泡孔的生长，使发泡不充分，难以得到高发泡率的泡沫塑料。选择K值57～60的PVC较为合适。

RawmaterialsofPVCwoodcompositeforextrusionfoaming,theselectionofPVCmolecularweightisveryimportant,itwillchangetherheologicalbehaviour,andgreatlyinfluenceonthegrowthofbubbles.Whenthemolecularweightislow,themeltstrengthispoor,anditwilldifficulttoblockthefoaminggastoescape,difficulttogettheevenbublesandsmoothfoam.Whenthemolecularweightishigh,thetensilestrengthofmeltisgreat,itwillinhibitedthegrowthofthebubles,sothatfoamingisnotsufficient,itisdifficulttogethighfoamingrateofthefoam.SelectingKvalue57~60ofPVCismoresuitable

.（1）PVC树脂的选择(1)TheSelectionofPVCResin不同品种的木粉，生产的塑木材料性能差别大。应考虑木粉的种类、表面自由能、填充量、粒径、含水量等的影响。Withdifferentspeciesofwoodpowder,theperformanceofWPCproductshasalargedifferences.Itshouldconsiderthetypesofwoodpowder,thesurfacefreeenergy,fillingvolume,particlesizes,moistureandotherfactors.

PVC塑木发泡中多为工业用木粉，尺寸约150μm。木粉填充量一般为(质量分数，下同)30%～60%。填充量越高，越不容易发泡。发泡中，木粉含水率较高会导致较差的泡孔结构、泡孔分布不均，泡孔表面差、不光洁等。因此，加工应尽量将木粉充分干燥。InPVCwoodcompositefoamingmostlyadoptingindustrialflour,thesizeisabout150μm.Fillingvolumeofwoodpowerusually30%~60%(massfraction).Themoreoffillingvolumethemoredifficulttofoam.Infoaming,ifthemoisturecontentwoodflourishigh,itwillleadtopoorcellstructure,unevendistributionofthecell,thecellsurfaceispoor,notcleanandsoon.Therefore,thewoodflourshouldbefullydried.

（2）木粉的选择及处理(2)SelectionandTreatmentofWoodFlour木质纤维的元素组成为：C约为50%，H约为6%，O约为44%，N约为0.05～0.4%；其主要成分为纤维素、半纤维素和木质素。Elementalcomposition

ofwoodfiber:Cisabout50%,Hisabout6%,Oisabout44%,Nisabout0.05~0.4%;themaincomponentiscellulose,hemicelluloseandlignin.纤维素：约占木材的50%，是D-葡萄糖以β-1,4苷键结合起来的链状高分子化合物，具有结晶结构，对酸或碱的抵抗性较半纤维素强。Cellulose:thecontentisabout50%ofwood,itiscombinedaspolymerchainstructureasβ-1,4glycosidebondstoD-glucose,withacrystallinestructure,havingstrongerresistancetoacidoralkalithanhemicellulose

.

（2）木粉的选择和处理(2)SelectionandTreatmentofWoodFlour半纤维素：约占20~30%，它是非纤维素的高聚糖类，大部分可溶于碱，通过加热或NaOH浸泡处理都可除去半纤维素。Hemicellulose:about20~30%,itispolysaccharidesclassofnon-cellulose,mostlyalkali-soluble.ThehemicellulosecanberemovedbyheatingorsoakinginNaOHsolution.

木质素：约占木材的20~30%，是以苯丙烷为基元，由C-C键和醚键结合起来的高分子芳香族物质，大部分不溶于有机溶剂。Lignin:about20~30%ofwood,itisbasedonphenylpropaneaselement,itispolymeraromaticsubstancescombinedbytheC-Cbondandetherbond

,mostlynotdissolvedinorganicsolvents.

木质材料一般根据外形可分为木粉(L/D=l~2)、木纤维(L/D=10)。根据不同的生产要求选择。Woodmaterialcanbegenerallyonappearancedividedintowoodpowder(L/D=l~2),woodfiber(L/D=10).Thechoicecanbemadeaccordingtodifferentproductionrequirements.

通常塑木复合中选用木粉粒径一般在20～200目。在此基础上，要保证木粉和塑料在混合前进行烘干处理。Usuallytheparticlesizeofwoodflourwhichisselectedandusedisinthe20to200mesh.Onthisbasis,toensurethatwoodflourandplasticsaredredbeforemixing.

需要一提的是，在用带排气功能的挤出机，特别是双螺杆挤出机加工塑木材料时，可以不对木粉进行特别的烘干处理，只需日光下自然干燥即可直接进行挤出加工。Needtomentionthat,whenusingextruderwithexhaustfunctionespetionallydouble-screwextrudertoprocessWPCmaterial,thewoodflourcannotbedriedspetially,butonlytodryundersunlight.

表1木材的化学成分(%)Chemicalcompositionofwood木材的化学成分Chemicalcompositionofwood%云杉松杨树木树枝树干树枝树干树枝纤维素(不包括聚戊糖)53.8～59.344.856.5～57.618.252.0～52.243.9木质素28.0～28.134.426.8～27.027.421.1～21.425.9聚戊糖9.5～10.512.810.4～11.010.122.7～22.928.7甘露聚糖7.5～～7.14.8无无半乳聚糖2.631.4～～0.70.8醚浸出物1.0～～～1.52.5热水可溶物1.7～～～2.54.9灰分0.20.260.20.270.260.33Table1Chemicalcompositionofwood(%)Chemicalcompositionofwood%spruce

pine

poplar

trunkbranchtrunkbranchtrunkbranchCellulose(notincludingpentosan)

53.8～59.344.856.5～57.618.252.0～52.243.9lignin

28.0～28.134.426.8～27.027.421.1～21.425.9heteropentosan

9.5～10.512.810.4～11.010.122.7～22.928.7mannosan

7.5～～7.14.8无无galactan

2.631.4～～0.70.8ether-solubleextractive

1.0～～～1.52.5Hotwatersoluble1.7～～～2.54.9Ash0.20.260.20.270.260.33表2稻壳的化学成分稻壳品种水分％灰分％粗纤维％木质素％多缩戊糖PH值SiO2在灰分中含量％早稻9.316.6134.7225.1816.397.195.72晚稻10.215.434.626.1316.287.5493.1稻壳粉RiceHuskPowderTable2Chemicalcompositionofricehusk

Varietiesofricehusk

moisture

％Ash％crudefibre：％lignin

％pentosan

PHValueThecontentofSiO2intheash

％earlyrice

9.316.6134.7225.1816.397.195.72laterice10.215.434.626.1316.287.5493.1RiceHuskPowder物理加工法Physicalprocessingmethod物理加工、干燥。Physicalprocessing,drying原纤的表面放电处理TheelectricdischargesurfacetreatmentofFibrillation

低温等离子处理法Low-temperatureplasmaprocessingmethod气爆法(STEX)Airblastmethod(STEX)

化学方法：Chemicalprocessingmethod

表面接枝法

Surfacegrafting界面偶合法Interfacecoupling乙酰化处理法Acetylationtreatment碱处理法Alkalitreatment酸处理法Acidtreatment有机溶剂处理法Organicsolventapproach（4）木粉处理方法TreatmentofWoodFlour偶联剂主要用于聚烯烃基WPC中，对改进和提高聚烯烃WPC制品性能十分重要。由于亲水的木纤维和憎水的聚烯烃塑料间的不相容性，木纤维与塑料界面粘附力小，未经处理木纤维填充的WPC性能不如纯聚烯烃，偶联剂可以改进和提高木纤维与塑料母体树脂间的粘附力，从而提高WPC性能。CouplingagentmainlyusedforpolyolefinbaseWPC,andimprovingthepropertiesofWPCpolyolefinproductsisveryimportant.Becauseofthepatibilitybetweenhydrophilicwoodenfiberandthosehydrophobepolyolefinplastic,theinterfaceadhesionforcebetweenthemisweek,thepropertiesofuntreatedwoodenfiberfillingWPCareworsethanpurepolyolefin.Socouplingagentcanimproveandenhancetheadhesionforcebetweenwoodfiberandplasticresinmatrix,improvingperformanceofWPC.（5）偶联剂CouplingAgent

偶联剂能够帮助:Couplingagentcanhelp

提高拉伸强度Improvethetensilestrength增强弯曲强度Enhancethebendingstrength加大冲击强度Increasetheimpactstrength降低吸水率Reducethewaterabsorption偶联剂能够增加亲水性木材和憎水性塑料之间的亲和力Couplingagentcanincreasethebondingbetweenhydrophilicwoodandhydrophobicplastic二、PVC发泡原理和过程发泡过程一般都要经过：Generaltogothroughthefoamingprocess:

形成气泡核→气泡核膨胀→泡体固化定型等阶段。Bubbleformation→Bubbleexpansion→Bubblecuringandshapingf.PrincipleandProcessofFoaminginPVC气泡核的形成气泡核的形成阶段对泡体中泡孔密度和分布情况起着决定性的作用，在温度和压力一定的情况下，气泡核数量决定了泡孔结构，并对最终制品的密度和发泡倍率影响重大。因此，气泡核的形成是控制泡体性能和质量的关键阶段。Bubbleformationstageplaysadecisiveroleonthedensityanddistributionofthecell,whenthetemperatureandpressurefixed,thenumberofbubbledeterminesthestructureoffoam,andsignificantlyinfluencethedensityandexpansionratioofthefinalproduct.Therefore,theformationofbubbleisthekeystagetocontrolofperformanceandquality.

TheFormationofBubble气泡核形成机理一、气液相混合直接形成气泡核。Themixingofgasandliquidisdirectlytoformnuclearbubbles.热固性泡沫塑料大多采用此法。

Thermosettingplastics

mostlyadoptthismethod.二、利用高聚物中的自由体积为成核点。Useofthefreevolumeinpolymersforthenucleationpoint.三、利用高聚物熔体中的低势能点为成核点。Useofthelowpotentialenergypointinpolymermeltfornucleationsites

将发泡剂（物理发泡剂）压送入高聚物的自由体积中，再通过升温降压的方法使自由体积中的发泡剂气化膨胀形成气泡核。Thefoamingagent(physicalfoamingagents)ispressuredintothefreevolumeofpolymer,andthenbywarmingandreducingpressuretogasifyfoamingagentandexpandthefreevolumeformingbubblesnuclear.

The

FormationMechanismofBubble气泡生长Bubblegrowth气泡成核后接着进入生长阶段，聚合物熔体中溶解的气体不断向泡核扩散，使周围聚合物中产生气体浓度梯度，浓度梯度的存在进一步促进了气体的扩散，也就促进了气泡的进一步生长。

Afterbubblenucleate,thengointothegrowthphase,thegasdissolvedinpolymermeltcontinuouslydiffusetobubblenuclear,sothatgasesproduceconcentrationgradientinpolymer.Theconcentrationgradientfurtherpromotethediffusionofgases,alsocontributetothebubblefurthergrowth.形成的气泡可能继续生长，也可能发生塌陷、破裂或合并。Bubblemaycontinuetogrow,itmaycollapse,crackedormerge.气泡的生长受多种因素影响，如温度、成核数量和气体的损失。Thegrowthofbubbleisaffectedbymanyfactors,suchastemperature,thenumberofnucleationandgaslosses.气泡生长Bubblegrowth影响气泡生长的主要因素

TheMainFactorsofBubbleGrowth影响因素主要两大类：Thefactorsaremaintwoclasses:一类属于发泡体系的物性参数，如气体的种类、扩散系数、溶解度、熔体的粘弹性、气体-聚合物熔体的界面张力等，这些参数主要通过界面间的物理传递来影响气泡增长；Oneclassisphysicalparameters,suchasthetypeofgas,diffusioncoefficient,solubility,meltviscoelastic,interfacialtensionbetweengasandpolymermelt,etc.Theseparametersinfluencethebubblegrowththroughphysicaldeliveryintheinterface.另一类属于加工工艺参数，如压力、温度、剪切速率、添加剂等，这类参数主要通过热力学性能来影响气泡增长。温度影响气体的扩散速度和熔体粘度，在成型过程中应精确控制温度。气体扩散对气泡生长影响也很显著，在熔体温度较高、扩散速度很大且熔体粘度很低时，气体的逃逸剧烈，会使泡孔膨胀率显著下降而无法得到发泡倍率较高的泡沫。Theotherisprocessparameters,suchaspressure,temperature,shearrate,additives,etc.Theseparametersinfluencethebubblegrowthmainlythroughthethermodynamicproperties.Temperatureaffectsgasdiffusionrateandmeltviscosity,themoldingprocessshouldbeprecisetemperaturecontrol.Gasdiffusioneffectonthebubblegrowthisalsosignificantlyhigherinthemelttemperature,meltviscosityandthediffusionvelocityislow,thegasescapesevere,thecellexpansionratewoulddeclinesignificantlyratiocannotbecomparedwithfoamhighfoam.泡体固化、定型

BubbleSolidifyingandShaping泡体的几何形状和结构，如泡孔的大小、开闭孔、泡孔的形状和分布是由膨胀阶段的条件决定的。Geometryandstructureofcell,suchasthecellsize,openorclosedcell,theshapeanddistributionofcellisdecidedbytheexpansionphase.膨胀能否达到预期的要求，与泡体的固化过程密切相关联。Ifexpansioncanmeetexpectationsornot,closelyassociatedwiththebubblecuringprocess.为了使已达到膨胀倍数的泡体结构固化定型，选择合适的固化时机和提高固化速度非常重要。Inordertohavethebubblestructurewhichhasreachedamultipleexpansioncureandshape,selectingtheappropriatecuringtimeandimprovingthecurerateisveryimportant.表1发泡剂基本性能名称缩写分解温度/℃气体产率/(ml·g-1)主要气体偶氮二甲酰胺AC200～230280～320N2,CO2(NH3)柠檬酸及其衍生物200～220110～150CO2,H2O4，4－羟基双（苯甲酰磺酰肼）OBSH140～165120～150N2,H2O5-苯基四唑5-BT240～250190～210N2碳酸氢钠120～150130～170CO2,H2O邻甲苯磺酰肼TSH110～140120～140N2,H2O对甲基磺酰氨基脲TSS215～235120～140N2,CO2（6）发泡剂FoamingAngent（6）发泡剂Table1ThebasicpropertiesoffoamingagentNameacronym

positiontemperature/℃gasyield/(ml·g-1)MaingasAzodicarbonamideAC200～230280～320N2,CO2(NH3)Citricacidanditsderivatives

200～220110～150CO2,H2O4,4-hydroxydouble

(Benzoylsulfonylhydrazide)

OBSH140～165120～150N2,H2O5-phenyl-tetrazole5-BT240～250190～210N2Sodiumbicarbonate

120～150130～170CO2,H2OO-benzenesulfonylhydrazide

TSH110～140120～140N2,H2OMethylsulfonylsemicarbazide

TSS215～235120～140N2,CO2FoamingAngent对化学发泡剂的要求是分解释放出的气体应为无毒、无腐蚀性、不燃烧，对制品的成型及物理、化学性能无影响，释放气体的速度应能控制，发泡剂在塑料中应具有良好的分散性等。Requirementsofthechemicalfoamingagentisthatthegasofpositionshouldbenon-toxic,non-corrosive,non-burning,havenoeffectontheproduct'sshape,andphysicalandchemicalproperties.Thereleasespeedofgasshouldbeabletocontrol.Thefoamingagentinplasticshouldbewelldispersedandsoon.（6）发泡剂FoamingAngent常用的化学发泡剂如AC热分解温度高，分解剧烈，易产生泡孔合并，分解温度过高，会导致木粉烧焦降解，必须添加一些助发泡剂，通过助发泡剂的活化引发它的分解，降低其热分解温度，使分解温度与PVC挤出温度相适应(降到160～170℃)。Commonchemicalfoamingagents,suchasAC,whichhasthehighthermalpositiontemperatures.Thepositionisintense,anditiseasytoproducethecellmerging.Whenthepositiontemperatureishigh,itwillleadtoburninganddegradationofwoodpowder,soyoumustaddsomefoamingpromotor.Theactivationoffoamingpromotorhelpcauseitspositionandreducethethermalpositiontemperature,fitthetemperaturewhichPVCextrudes(downto160~170℃).（7）助发泡剂FoamingPromotor常用的助发泡剂是三盐基硫酸铅、二盐基亚磷酸铅、硬脂酸钙、硬酯酸锌等。AC发泡剂与助发泡剂的使用比例常为1∶(1～3)。

Commonfoamingpromotoristribasicleadsulphate,dibasicleadphosphate,calciumstearate,zincstearateandsoon.TheoftenusedratioofACfoamingagentandfoamingpromotoris1:(1~3).温度和时间对AC发气量的影响

TheInfluenceofTemperatureandTime

ontheGasYieldofAC

温度和时间的变化直接决定发气量的大小，温度与发气量关系如图1所示，时间与发气量关系如图2所示。Changesintemperatureandtimedirectlydeterminesthesizeofgasevolution,therelationshipbetweentemperatureandgasevolutionshowninFigure1,relationshipbetweenthetimeandgasevolutionshowninFigure2.助发泡剂对AC发泡剂分解温度的影响发泡剂和助发泡剂配方①分解温度/℃发气量/(ml/g)AC3195-200220AC+氧化锌3:1165-180220AC+硬脂酸锌3:1150-180230－240AC+硬脂酸钙03:1.5135-160210－230AC+硬脂酸铅3:1160-200195－220①每百份树脂中份数助发泡剂FoamingPromotor

TheinfluenceoffoamingpromotoronthepositiontemperatureofACfoamingagentFoamingagentandpromotorformular①position/℃Gasevolution/(ml/g)AC3195-200220AC+zincoxide3:1165-180220AC+zincstearate3:1150-180230－240AC+calciumstearate03:1.5135-160210－230AC+leadstearate3:1160-200195－220①fractioneach100resins增塑剂的作用是促使PVC塑化熔融，提高熔体强度和延展性，使发泡过程较稳定。TheroleofplasticizeristopromotePVCplasticizingandmelting,increasedmeltstrengthandextensibility,makingthefoamingprocessmorestable.研究表明，PVC/木粉复合材料挤出发泡，丙烯酸是一种非常有效的增塑剂。配方中加入丙烯酸可降低熔体的刚性和粘度，有利于气体扩散和气泡生长，对减小制品的密度效果明显。其最佳用量为6%～8%。其它常用的增塑剂有邻苯二甲酸二丁酯（DBP）、邻苯二甲酸二辛酯（DOP）及癸二酸二辛酯等。Theresultsshowthat,inPVC/WoodFlourCompositesextrusionfoaming,acrylicacidisaveryeffectiveplasticizer.Formularwithacrylicacidcanreducetherigidandviscosityofmelt,itcanhelpgasdiffuseandgrow,significantlyreducethedensityofproducts.Theoptimumdosageis6%to8%.Othercommonplasticizersaredibutylphthalate(DBP),dioctylphthalate(DOP)anddioctylsebacate,etc.实际加工过程中，为避免熔体强度不够，可适当减少DOP用量，改加一些发泡调节剂（如530）等。Inactualprocessing,inordertoavoidunenoughmeltstrength,mayappropriatelyreducingtheamountofDOP,addingsomefoamingregulators(suchas530)andsoon.（8）增塑剂Plasticizer

改善填料的混合性、分散性；Improvethemixinganddispersionoffiller

促进塑化，改善流动性promotplastifying,improvemobility提高挤出速度，降低设备扭矩和温度Improvetheextrusionspeed,reducetorqueandtemperature良好的外观和质感，消除边缘撕裂；Goodlookandfeel,eliminateedgetear

有助于塑木共混(各项性能更优)；HelpblendWPC(theperformancebetter);提高产能，降低综合成本。Increaseproductivity,reducetotalcost.

（9）润滑剂LubricatingAgent助剂应用热稳定剂防止加工过程中聚合物降解抗冲改性剂提高冲击强度光稳定剂防止紫外光对聚合物的伤害着色剂美化制品表面，并有一定紫外防护能力抗菌剂防止细菌真菌侵蚀OtherAg