This is a presentation on MVP Preparation and Characterization of MVP Polymers Bill Gross, Bill Hsu, and Adel Halasa* The Goodyear Tire and Rubber Company Akron, OH
MVP Polymer Preparation of MVP via Anionic Polymerization employing three monomers Isoprene for traction styrene for strength and butadiene for wear the catalyst system is n-BuLi and the modifier is TMEDA
MVP Polymer It is well known in the Rubber Industries that a tread rubber is a blend of two or three polymers in order to balance traction wear and RR( fuel saving) The major problem with this concept is the following. A. miscibility. B filler distribution& dispersion
MVP Polymer In this approach we are attempting to micro-engineer the molecular chain to avoid all the problems of polymer blend and filler distribution. Anionic polymerization of S/I/B ter-polymer has met this criteria
Reactivity Ratio of MVP Polymer The reactivity ratios of the three monomer employed in this system are dependant on the polar modifier TMEDA the r1 for Bd and r2styrene are enhanced while r3 for Isoprene is decreased thus microstructure which control the Tg is dependant of the modifier addition to the polymerization
MVP Polymer In this system we used Batch polymerization methods to control the MVP molecular design via the addition of TMEDA during the reaction and taking samples for analysis
Symbolic MVP Polymer Chain Modifier added Low Tg (Wear) Phase mixing High Tg (Traction)
Microengineering Polymer Chain by Polymer Synthesis Using three monomers; styrene, isoprene, and butadiene Using polar modifiers added during the polymerization Controlling molecular weight by catalyst concentration Controlling microstructure by polar to catalyst ratio Coupling polymer chains to improve the processibility Controlling Tg by styrene concentration Controlling Tg by isoprene microstructure
Conversion vs Time for SIBR
DSC of MVP Polymer % Conversion Temperature (ºC) -79 ºC -40 ºC -80 ºC -120 -100 -80 -60 -40 -20 20 40 -79 ºC -80 ºC -40 ºC -20 ºC -19 ºC Temperature (ºC) % Conversion 30 % 50 % 80 % 100 %
Microstructure of MVP/SIBR
Microstructure of MVP/SIBR
Tg of MVP Polymer
Theoretical Integral Polymer
Physical Properties of Polymer in CB Tan δ -20 Tan δ 0 Tan δ 60 IBR 0.535 0.252 0.086 45/45/10 0.520 0.370 0.061 40/40/20 0.388 0.500 0.078 35/35/30 0.834 0.115 High Tan δ -20; Excellent wear, High Tan δ 0; Excellent traction, Low Tan δ 60; Excellent rolling resistance.
Blends (50/50 NR) Polymer Tan δ -20 Tan δ 0 Tan δ 60 IBR 0.299 0.145 0.075 45/45/10 0.492 0.165 0.062 40/40/20 0.550 0.285 35/35/30 0.089 0.419 0.098 High Tan δ -20; Excellent wear, Low Tan δ 0; Excellent traction, High Tan δ 60; Excellent rolling resistance.
Blends of MVP Polymer with 70/30 cis-PBD Tan δ -20 (Wear) Tan δ 0 (Traction) Tan δ 60 (RR) IBR 0.395 0.146 0.092 45/45/10 0.350 0.205 0.063 40/40/20 0.421 0.240 0.072 35/35/30 0.093 0.524 0.097 High Tan δ -20; Excellent wear, Low Tan δ 0; Excellent traction, High Tan δ 60; Excellent rolling resistance.
Tan Delta of MVP Polymer with Styrene Contents Temperature (ºC) -100 -80 -60 -40 -20 20 40 60 Log Tan δ -1 -2 -3 10 % 20 % 30 %
MVP/NR (50/50) Log Tan δ Temperature (ºC) 10 % Styrene 30 % Styrene -100 -80 -60 -40 -20 20 40 60 Log Tan δ -1 -2 -3 10 % Styrene 30 % Styrene IBR
MVP/PBD (70/30) Log Tan δ Temperature (ºC) IBR 30 % Styrene -100 -80 -60 -40 -20 20 40 60 Log Tan δ -1 -2 -3 10 % Styrene 30 % Styrene IBR
Acknowledgements Author would like to thank Goodyear Tire and Rubber Company Management for permission to present this project. Author would like to thank many His colleagues for their comments and suggestions.