The Title is Trans-SBR a Crystallizable Elastomer Rubber Division Presentation Akron Ohio, April 27, 2010 This a presentation was given at the Rubber Division Spring meeting 2010 The Title is Trans-SBR a Crystallizable Elastomer Adel F Halasa The Goodyear Tire & Rubber co.
Agenda Objectives. Catalyst System. Catalyst Preparation Polymerization Batch Continuos Polymer Characterization Polymer Properties
Objectives The Objectives of this research is to prepare new polymers with crystalline unites & control Microstructures& sequence distributions that open the door to a new viscoelastic behavior Improve traction Improve wear reduced rolling resistance
Objectives Continued Better adhesion Reduced Chipping and chunking in RMT Improved tear strength Building tack Improved dimensional stability Improved durability
Conjugated Diene Microstructures Butadiene 1,4-Trans 1,4-Cis 1,2/V Wear ++ ++ -- Traction +- -- ++ RR ++ ++ ++ Isoprene Wear -- ++ +- Traction +- +- ++ RR +- - ++
Strain crystallizes Polymers Reduces chipping/chunking damage in RMT, farm application,stump penetration OTR Low hysteresis Lower running Temperature Sufficient green strength good tire building properties less shrinkage dimensional stability
Barium Catalyst System Comparison Microstructure Tg (oC) Tm Copolymerize Styrene trans-1,4 cis-1,4 1,2 Ziegler-Natta 80 4 16 -75 40 NO Alfin 77 23 -67 YES Ba/Mg/Al 70-90 27-7 3 -90
Background Of Trans Polymers Alfin catalyst Ally Sodium/Sodium Chloride/Sodium Isoproxide ( 1/1/1) Extremely high molecular weight difficult to process Co-polymerize styrene and butadiene Styrene incorporation is 10% Max. Co-polymer has 30 to35% Vinyl difficult to oil extend due to the extreme molecular weight
Background continued Potassium system Potassium tert-Amyloxide (KOAM)/ R2Mg KOAm/R3MgK KOAM/TMEDA/R3MgK (3/1/1) PBD 98% Trans structures resin form-need a hot house to process Do not co-polymerize styrene to form trans structures but form 1,2 co-polymer
Background Continued Transition Metals catalyst Cobalt Octoate/TIBAL/Nonylphenolate( 1/10/10) Does not form copolymers of styrene or Isoprene Tg of PBD -75ºC Highly crystalline structure need hot housing Tm +40ºC
Barium System Barium alkoxide in combination with dialkymagnesium or Aluminum alkyls have been used to co-polymerize styrene and butadiene with trans structures J.G. Hargis, et al., Acs Symp ser 1982, 193 ( Elastomers and rubber Elasticity), 73-100 Barium alkoxide usually are made from Barium metal in liquid ammonia and the corresponding alcohol
Barium System Our discovery: Cheaper method of making Barium compounds from Barium hydroxide The use of Organo-lithium in conjunction with Aluminum alkyls The use of polar modifiers to increase the Trans-contents and at faster reaction rates at higher temperatures
Barium System continued. Our Procedure Barium metal = $ 110/lb. Ba(OH)2 + DEGEE = Ba(OH)2 + THFA= Ba(OR)2 + H2O Ba(OH)2 + Thymol= Barium Hydroxide monohydrate =($0.30) DEGEE ( Di (ethylene glycol) Alkyl ethers
Barium System Catalyst Components: Optimal ratios 1/4/3 Ba(OR)2 Barium Alkoxires Trioctyl aluminum(TOA) n-butyllithium( BuLi) Optimal ratios 1/4/3 Ba(OR)2
NMR Analysis Solution 400 MHz C-13 and H-1 NMR were used to determine the SBR composition, Bd microstructure, and styrene sequencing.
Continuos polymerization
TRANS_POLYMER
Tm verses Trans-Content(PBD)
Trans-PBD Morphoploy
Tm Verses Trans-Contents
Trans-SBR
TRANS_SBR