1、Contents1.Elastomers2.Carbon Black and related Techniques3.Silica and related Techniques4.Chemicals1.Elastomers POLYMERIrregular structure(amorphous)Regular structure(crystalline)Tm RTNatural rubberRubberPlasticPlasticTg RTPolystyrenePolymethyl-methacrylateTm RTTg RT NylonTg BuLi catalyst =Non polar
2、 solvent(increase Butadiene addition)=add ethers or amines(increase 1,2 butadiene)Neoprene(Polychloroprene)-CR =2-chlorobutadiene =Mostly trans 1,4,Tg=-50oC =If Polar Cl increases,weathering resistance(O2,O3)Low permeability Heat resistance Solvent and flame resistance Adhesion to polar substances e
3、.g.metal Cl increases interchain interaction promoting crystallization.Synthetic Polyisoprene(IR)-.Anionic polymerization with butyl lithium =92-95%cis 1,4-polyisoprene -.Coordination polymerization with Ziegler-Natta catalyst =trialkyl Al/TiCl4(ratio important for high cis 1,4 IR)=Poor aging proper
4、ties than Butyl Li based IR Because of catalyst residue.-.IR has less green strength and tack than NR Polybutadiene(BR)-.cis-1,4 polybutadiene:Tg=-103 oC -.atactic,vinyl BR,Tg=-3 oC -.Narrow MWD and linear BR exhibit low hysteresis,high resilience and good abrasion resistance,but show poor mixing,lo
5、w green elongation,high cold flow and dont band on mill.Butyl Rubber -.Isobutylene-isoprene(1-2%)copolymer -.Tg=-70oC -.Cationic polymerization =catalyzed by AlCl3 in methyl chloride at-100oC -.Unusually low resilience for having such a low Tg -.Excellent aging properties -.Quite impermeable to gas
6、-.Butyl rubber can be chlorinated(about 1%)for increasing compatibility with NR or SBR and also enhancing curing rateEthylene Propylene rubber(EPR,EPDM)-.Lowest density rubber -.Tg=-70oC -.Third monomer:non conjugated monomer -.E/P ratio=50/50 to 75/25 -.Excellent resistance to weathering,o2,o3 -.Ca
7、n be made partially crystalline for high green strengthPolysulfide rubber-.About 80%sulfur by weight -.ClCH2CH2Cl+Na2S4-(-CH2CH2S4-)-+2NaCl -.Best resistance to ketone,esters and most solvents -.Low permeability -.Used for fuel tank solvent,fuel hose liner and gaskets Chlorosulphonated polyethylene(
8、Hypalon)-.25-45%Cl -.1-1.4%sulfur -.Extremely stable chemically -.Good color retention after UV exposure -.O3 and flame resistance -.The more Cl,the higher density and improved-oil resistance -.The less Cl,the better low temperature flex and heat-aging.Silicone Rubbers-Tg=-127oC-.Used 0.5%vinyl mono
9、mer for cure-.Organic-inorganic nature:excellent aging at high temperature-.Low strength and high resilience Microstructure of Solution SBRSolution polymerization process can control the microstructure of Styrene-Butadiene Copolymer(SBR)Isomers of Butadiene Unit in solution SBRm m()C C H HC C H H2 2
10、C C H H2 2C C H HC C H HC C H H2 2()n nVinylC C H H2 2C C H HC C H HC C H H2 2CisH HC C H H2 2H HC C H H2 2TransC C H H2 2H HH HC C H H2 2 CURE CHARACTERISTICS Slower Cure Rate Higher Marching Modulus Lower max.Torque at optimum cureHigher Vinyl Contents Time(min.)0 0101020203030404050500 0101020203
11、030404050506060:13%Vinyl:40%Vinyl:73%VinylTorque(lb.inch)Marching Modulus Ratio=(T60-Tmin.)/(T15-Tmin.)1001020304050607080510152025303540Y=1.7694+0.437*X (R2 =0.9768)Vinyl Content(%)End of Cure(min.)102030405060708005101520253035Vinyl Content(%)Marching Modulus Ratio(%)Y=-4.365+0.473*X (R2 =0.9939)E
12、nd of CureMarching Modulus020406080100253035404550Bound Rubber(%)Vinyl content(%)1020304050607080130140150160170180190200210INITIAL1 day aging3 day agingTensile Strength(kgf/cm2)Vinyl content(%)1020304050607080505560657075808590Tear Strength(kgf/inch)Vinyl content(%)INITIAL1 day aging3 day aging1020
13、304050607080303234363840Wear Loss(mg)Vinyl content(%)Bound Rubber vs Ultimate Strength(T.S.,T.R.,WEAR)Index of Physical PropertiesVINYL CONTENT(%)20304050607080INDEX OF PHYSICAL PROPERTIES050100150200250DIN ABRASION(R2=0.9249)CUT&CHIP(R2=0.9639)BASE LINE(INDEX=100)HEAT-BUILD-UP(R2=0.7893)REBOUND(R2=
14、0.9675)VINYL CONTENT(%)20304050607080INDEX OF PHYSICAL PROPERTIES010020030040050060070080090010001100120013001400MARCHING MOD.RATIO(R2=0.9939)DYN.CUT GROWTHRATE(R20.9467)FTF AFTER AGING(R2=0.9593)END OF CURE(R2=0.9768)T40(R2=0.8349)102030405060708002e-54e-56e-58e-51e-41e-41e-42e-42e-42e-4 :TOTAL :MO
15、NO&DI-SULFIDE :POLYSULFIDER2=0.8947R2=0.9950R2=0.9847CROSSLINK DENSITY&TYPEVinyl Content(%)Crosslink Density Test Method:Swelling Methods Interaction Parameter 1020304050607080-50-40-30-20-10010Vinyl content(%)Tg ()Tg vs Vinyl ContentY=-46.4+0.620*X (R2=0.9408)10203040506070800.02.0e-54.0e-56.0e-58.
16、0e-51.0e-41.2e-4Vinyl content(%)Crack Growth Rate(mm/cycle)Crack Growth RateY=1.8486e-5+1.6585e-6*X(R2=0.9467)-101-0.30.00.30.60.91.21.5Vinyl=13%73%30%67%Tearing Energy vs Pre-cut Size The lower vinyl content,the higher crack resistance At very low vinyl content(13%)two different slopes observed(sim
17、ilar behavior of crystalline polymer).Log C0(mm)Log T(kJ/m2)Index of Physical Properties P.P of S-SBR with X%VinylINDEX OF P.P=P.P of S-SBR with 13%VinylVINYL CONTENT(%)20304050607080INDEX OF PHYSICAL PROPERTIES050100150200250REBOUND DECAY(R2=0.9304)BLOW-OUT(R2=0.7975)GLASS TRANSITION TEMP.(R2=0.940
18、8)VINYL CONTENT(%)20304050607080INDEX OF PHYSICAL PROPERTIES050100150200250POLYSULFIDIC(Sx)(R2=0.8947)TOTAL X-LINK DENSITY(R2=0.9847)MONO-&DISULFIDIC(S1+S2)(R2=0.9950)Increasing Vinyl ContentsReactivity of Polymer Main Chain(Backbone)DownWhy?Decreasing Reactive Allylic Hydrogen in Cis&Trans UnitAlly
19、lic HydrogenVinylic HydrogenReactivityRelatively HighLowAct.Energy(E)88 kcal/mol108 kcal/molReactive HydrogenSlow Cure RateCH-CHCH-CH2 2CHCH2 2-CHCH-CHCH2 2-CH=CH-CH-CH=CH-CH2 2()()0.25 0.25 ()()mm()()n n CHCHCHCH2 2E*(Complex Modulus)Tan(E”/E)As the Vinyl Content increases,Chain rigidity increases
20、due tobulky vinyl group in the main chain resulting in higher Tg.0 00.10.10.20.20.30.30.40.40.50.50.60.60.70.7-80-80-60-60-40-40-20-200 02020404060608080VinylVinyl=13%=13%39%39%73%73%0.00.00.50.51.01.01.51.52.02.02.52.53.03.03.53.5-80-80-60-60-40-40-20-200 0202040406060VinylVinyl=13%=13%39%39%73%73%
21、Temperature()Temperature()Tan(E”/E)E*(X X1010 dyne/cm2)Vinyl content effect of BR on Tg Tg,oC%1,2 substitution(Vinyl)0-20-40-60-80-100 20 40 60 80 100Isobutylene-Based Elastomers CH3 CH3 (CH2 C)(CH2 C C CH2)x|yCH3 H CH3 CH2 CH2 C CH2 C CH CH2 CH3 XCH2CHCH2CH3CH2CCH3CH3CCH2CHCH2BrCH3CH3(X=Cl or Br)Bu
22、tyl rubber:IIRHalogenated butyl rubber:BIIR,CIIRBrominated isobutylene-co-para-methylstyrene:BIMS orEXXPROTMLow Permeability in Isobutylene-Based PolymersEfficient packing in isobutylene-based polymers leads to their low fractional free volumes and low air permeabilitySame dependence of permeability
23、 on T-Tg as other diene rubbers but with significantly lower permeability valuesAmong isobutylene-based polymers,permeability follows BIMS BIIR BrSBB Less than 1 m =Upper limit:about 400 m2/cm3-.Carbon black,silica,treated corn starch.*Carbon black is incomplete combustion of hydrocarbons or by ther
24、mal cracking.Furnace black:Gas or fuel oil is burned in excess air and water quenched =Surface:low oxygen content,neutral or alkaline =Size:100-1000Ao Thermal black:Oil and natural gas is cracked in the absence of oxygen at a hot refractory surface =Size:1000-5000Ao ASTM designation N series:normal
25、curing S series:slow curingParticle Size for Rubber Reinforcement Particle size Effects Particles 5000 nm Degrade physical properties of rubberParticles between Little effect on tensile strength 1000 5000 nm large volumes can be used with little degradation of rubber.Particles 1000 nm ReinforceParti
26、cles 1 nm Real reinforcing agents Functional Groups of Carbon Black SurfaceThe surface of carbon black is complex and not clear01020304050607080901001101201301401501601701801900102030405060708090100 110 120 130 140 150 160 170 180 190NSA,m2/gDBP,ml/100gN774N660N550N330N351N326N220N375N339N115N110N12
27、1N234CD-2045CD-2041N990N103CD-2056BCD-2056ACD2007CD2005CD2038CD-2049HV3396 Dimensional Clarification of C/B GradesHydrodynamic Theories E =Eo(1 +2.5 )where =volume fraction by Guth RF(Reinforcing factor)=E/Eo =(1 +2.5 )E =Eo(1 +2.5 +14.1 2)by Smallwood E =Eo(1 +0.67 +1.62 f2 2)where f=shape factor T
28、okitas FormulaThe peak of abrasion resistance appears at low carbon black loading,when the carbon black has high CDBP and narrow aggregate size distribution.406080100120203040506070CB l oadi ng,phrAbrasion resistance indexGeneral properties of Carbon black-.N series activate accelerated sulfur vulca
29、nization by promoting cleavage of S-N bond in sulfenamides or promote evolution of H2S-.C/B decrease scorch time,but increase cure rate.-.C/B tends to reduce reversion.-.C/B seem to have little effect on crosslinks-.C/B have antioxidant activity(Quinonic surface groups)Particle size 1)Structure(aggr
30、egate)=CDBP 2)Aggregate Size Distribution=Dst,Tint 3)Surface ActivityThe ASTM Value of Carbon BlackN110N115N121N125N220N234N299N326N330N335N339N347N351N358N375N472N550N589N630N660N774N990I2 No.DBPCDBPN2SATINT300%MCTAB145160121117121120108828292909068849025043100363629-1131131321041141251247210211012
31、0124120150114178121180789072439896112810010010569889410110097112971148411462756240126128121126111119104838288938773889614542763536299143145132132119126108848388969073871002704280383529912412312112311512411311210311011010310099115-0-0.2+3.3+0.6+0.9+2.3+3.3-1.7+1.7+3.3+5.2+3.1+3.7+5.4+2.9-1.8+1.7+1.3-
32、1.2-0.1-1.4-5.5 Rubber Property Structure Particle size Increase DecreaseMixing Temp Increase Increase Dispersion Improves Decrease Viscosity Increase IncreaseGreen Strength Increase IncreaseScorch safety Decrease DecreaseTensile Decrease(Slightly)IncreaseElongation Decrease DecreaseHardness Increas
33、e IncreaseTear Resistance Decrease IncreaseCompression set Increase(Slightly)IncreaseResilience Decrease(Slightly)DecreaseHeat build-up Increase IncreaseAbrasion Resistance Increase(Slightly)IncreaseRelationship between carbon black loading and physical properties of rubber compound.Particle Size St
34、ructure C/B loadingUn-cured rubberVulcanized rubberMixing timeDispersion Mill-BaggingViscosityScorch timeDie-SwellHardness300%ModulusTensile strengthTear strengthAbrasion propertiesReboundHeat Build-upCompound propertiesC/B basic properties ItemsAbrasion Grip cut&ChipRolling resistancePhysical prope
35、rtiesAbrasiontantan,ModulustanSurface Area,N2SAStructure,DBPSeverity:Surface Activity,N2SA/IA ASDTintSharp Sharp Sharp Broad ConsiderationHeat Build-upViscosityProcessProcessAbrasionAbrasionApplicationN234,N103N103N220N375,CD2045 Surface Model of neo-BlackCOOHCOConventionalneo-BlackSoft Bondingpolym
36、erSoft Bonding=polymer-like=Low tan,Low EHard BondingCarbon BlackCOOHCOCarbon BlackClassification of C/B for tire components TBRPCRTreadUnder treadSide wallCarcassBeltInner linearApex/Rim flangeBase stripN234,N375,N330N660N550N660N326,N351N550N351,N375N351N103,N220,N234N351N351N330N330N660N330,N351N
37、351ComponentsType3.Silica and related TechniquesDefinitionTypes1)Reinforcing agent:Silica,Hard clay2)Filling agent:Soft clay,CaCO3,Ca(OH)2,TALC.Required properties.1)Good dispersity of filler2)No effect of possibility.3)No effect against water,chemicals,thermal and sun-light.4)High filling of filler
38、 in compound.5)Low cost Inorganic filler 1)Reinforcing agent is used for improving hardness,tensile strength,tear strength and abrasion resistant 2)Filling agent is used for reducing cost,improving possibility and increasing rubber volume without deteriorating physical properties.Current situation A
39、pplied filler SILICA HARD CLAY SOFT CLAY CaCO3 Compound Tread W/hite Side wall Bead coating,Carcass Inner liner General information of SilicaSilicaSilicaC/BC/BFiller/FillerFiller/FillerinteractioninteractionStrongStrongWeakWeakPolymer/FillerPolymer/FillerinteractioninteractionWeakWeakStrongStrongCou
40、pling agentCoupling agentNecessaryNecessary-Chemical structureTypes1)Raw silica2)Silane coupled silica3)New silica(High dispersible)Properties 1)Advantage :Improvement of R/R&Wet traction Low H.B.U and good CUT&CHIP Excellent Snow&Ice traction 2)Dis-advantage:Poor dispersity and processing problems.
41、Silica vs.Carbon blackSiO2+-(-Six(OH)y-)n-Natural SilicaSynthetic Silica-Amorphous type Fumed silica(pyrogenic process)-Anhydrous silica Electric arc silica(Pyrogenic process)Fused silica Silica gel(Wet process)Precipitated silica(Wet process)-Hydrated silica Precipitated silica Na2CO3 H2O/H2SO4 Hig
42、h purity sand=Silicon oxide =Silicate glass(SiO2/Na2O)=SiO2 (SiO2/Na2O)aq +2 H2SO4 SiO2 +Na2SO4 +H2O Polymerization Nucleation Growth Aggregation Consolidation Manufacturing method of silica Manufacturing method of silica SandH2Ooven1400dissolutionmixing chamberSodium carbonate DilutionLIQUIDSILICAT
43、EVITROUS SILICATESiO2 in powderstoragegrindingcompactingmicronisationH2SO4SprayDryingslurry SiO2+H2Ocakeprecipitationfiltration washingliquefactionGeneral properties of silicaHighLowAffinity with PolymerNon-PolarPolarPolarityCARBON BLACKSILICACONTENTSStructureLowHighFiller-Filler InteractionPhysical
44、 RelationChemical Bonding(with Silane Coupling Agent)Polymer-Filler BondingMediumHighCostCoupling Reaction of Silica/Silane/PolymerSilanol Groupof SilicaBis-(3-Ethoxy Silylpropyl)-Tetrasulfane(Si-69)SiSiO OH HSiSiO OH HSiSiO OH HSiSiO OH HSiSiO OH H+C C2 2H H5 5O OSiSiO OC C2 2H H5 5O OC C2 2H H5 5(
45、C CH H2 2)3 3S S4 4(C CH H2 2)3 3SiSiO OC C2 2H H5 5O OC C2 2H H5 5O OC C2 2H H5 5-C C2 2H H5 5O OH HSiSiO OSiSiO OSiSiO OSiSiO OSiSiO O H HSiSiSiSiO O C C2 2H H5 5(C C H H2 2)3 3(C C H H2 2)3 3O O C C2 2H H5 5S SS SS SS SSiSiO OSiSiO OSiSiO OSiSiO OSiSiO O H HSiSiSiSiO O C C2 2H H5 5(C C H H2 2)3 3
46、(C C H H2 2)3 3O O C C2 2H H5 5S SS SS Sx xSiSiO OSiSiO OSiSiO OSiSiO OSiSiO O H HSiSiSiSiO O C C2 2H H5 5(C C H H2 2)3 3(C C H H2 2)3 3O O C C2 2H H5 5+R R U U B B B BE ER RA Ac cc c /S S8 8S Sa aSbSbP PIntermediate Coupling Agent TESPT(SI-69)Bis-(3-EthoxySilylPropyl)-Tetrasulfane Mercapt Silane -M
47、ercaptopropyltrialkoxy Silane TCPTS(SI-264)3-ThioCyantoPropylTriethoxy Silane CSPTES 3-Chloropropyl Troexhoxy Silane VTES(SI-225)Trialkoxy Vinyl Silane Performance comparison of Silica vs.Carbon Black CompoundsCARBONSILICACONTENTS100105Wet Traction100110Rolling Resistance10097WearProperties0 tanHydr
48、ophilic-OH GroupHysterisysDispersionPolymerHighLowLowS-SBRLowHighHighE-SBR-60-50-40-30-20-100102030405060708090Silica CompdCB CompdWet TractionRegionR.R.RegionTan Delta Comparison of Silica vs.Carbon Black CompoundEfficiencyProcessing CostAbrasionSNOWWETR.R.ClassificationWorseBetter“Green Tire Conce
49、pt”introduced into European Market.This can be achieved mainly with silica/silane system and a special solution SBR polymer to overcome the trade-off problem in performances among wet grip,rolling resistance and abrasion.Poor interaction of silica with elastomer leads to the careful selection of mic
50、rostructure of solution SBR to get optimum reinforcement.BACKGROUNDWet gripAbrasion resistanceR/RSilica+Si69ASTM C/BSilica Application for Green Tire Control 1.2phr silane Tensile strength(kg/cm2)171 234300%modulus(kg/cm2)67 154Elongation,%500 384Shore A hardness 61 56Rebound 67 70Heat Build-up 25 1
