Transcript Corporate New PowerPoint Guidelines

Anionic Synthesis of Liquid
Polydienes and Their Applications
Taejun Yoo* and Steven Henning
October 14, 2009
Contents
Anionic synthesis of liquid polydienes
 Microstructure
 Macrostructure
 Functionalization
Structure and properties
 Microstructure
 Macrostructure
Applications
Liquid polydiene
- Low molecular weight homopolymers or copolymers containing unsaturated carbon-carbon double bonds
- Curing by sulfur or peroxides
Molecular weight
Physical state
Processing
Polymerization type
Modification
Catalyst cost on product
Application
Liquid polydiene
Elastomer
1,000-10,000
100,000-1,000,000
Viscous liquid
Solid
Low shear
High shear
Batch or semi batch
Batch or continuous
Easy
Relatively harder
Critical
Negligible
Additives for rubber
products
Main rubber products
Why anionic polymerization?
Microstructure




Polymer composition (styrene, butadiene, isoprene)
Mode of addition (1,4- and 1,2- vinyl or 3,4-vinyl)
Monomer sequence distribution (random, tapered or block)
Cyclic structure (batch vs. semi batch)
Macrostructure
 Molecular weight and distribution
 Molecular geometry (linear and branched)
Functionalization
 In chain
 Chain end: mono and difunctional (telechelic)
A variety of different liquid polymers !
Commercial liquid polydienes (anionic)
-Plastikator 32
-Butarez (HTPB and CTPB)
Producer
Liquid
polymer
Trade name
MW
Nippon Soda
PB
Nisso
Ricon
Sartomer
Synthomer
1,2-vinyl
(%)
Functional
group
1k-4k
85-90
OH, COOH
1.5k-8k
20-90
Post
polymerization
Modification
Maleinization
Hydrogenation
Epoxidation
PB, SBR
Maleinization
Krasol
2k-10k
60-65
OH
PB
Lithene
1k-9k
10-55
OH
Maleinization
PB, PI
LBR
25-50k
-
OH, COOH
Maleinization
Kuraray
SBR, SIR
LIR
Hydrogenation
Microstructure
Mode of addition (1,4- vs. 1,2-)


Reaction conditions
Comonomer effect in copolymerization
Cyclic vinyl formation
Microstructure of polydienes
R
C
CH
CH2
R
C
H2C
H2
C
Trans-1,4-addition
H2
C
R=CH3 or H
R
CH
C
H2
C
R
CH2
1,2-addition
Tg (°C)
Tm (°C)
Cis 1,4-
- 107
2
Trans 1,4-
-106
97/145
Isotactic 1,2
-15
128
Syndiotactic 1,2
-28
156
1,2-vinyl*
-4
-
* amorphous
CH
C
HC
CH2
3,4-addition
Microstructure
CH
CH2
Cis-1,4-addition
Diene
H2C
R
CH
CH2
H2C
CH
H2C
Cyclic vinyl
Counter ion and initiator concentration effect
Catalyst
Cis-1,4
Trans-1,4
1,2
Lithium catalyst
Lithium
35
52
13
 soluble in hydrocarbon solvents
Sodium
10
25
65
Potassium
15
40
45
Rubidium
7
31
62
Cesium
6
35
59
PI
PB
 the lowest 1,2-vinyl content
 good low temperature properties
Initiator Concentration (M)
1.4-Cis (%)
1,4-Trans (%)
3,4-Vinyl (%)*
6.12x10-2
74
18
8
1.0x10-3
78
17
5
1.0x10-4
84
11
5
0.8x10-5
97
0
3
5x10-1
53
47
5x10-2
90
10
5x10-3
93
7
* 1,2-vinyl for polybutadiene
Polar additive and Temperature effect
(RLi)n
80
-
n RLi
1.2-vinyl (%)
aggregated
60
R- // Li+
40
Contact ion pair
-
+
R + Li
Free ions
30 C
70 C
20
 Polar solvent
0
0
0.5
1
1.5
 Presence of Lewis base (alkali metal
alkoxides) in HC solvent
TMEDA/NBL (molar ratio)
1.2-vinyl (%)
+
R , Li
80
 Monodendate vs. Bidendate
60
 Temperature
40
30 C
70 C
20
0
0
20
40
60
80
100
THF/NBL (molar ratio)
T.A. Antkowiak, A.E. Oberster, A.F. Halasa, and D.P. Tate JPS, Part A-1 Vol. 10, 1319 (1972)
Polybutadiene with the highest 1,2-vinyl can be prepared in polar solvent
at lower reaction temperature
Comonomer effect (random copolymerization)
-Adding polar additives
-Maintaining the concentration of comonomer with a lower monomer
reactivity ratio high during the copolymerization.

Normalized vinyl (%)
80

75
Li

LB
70
65
60
55
50
45
40
0
5
10
15
20
25
30
35
40
45
50
Incorporated styrene (%)
Li
LB
Effect of styrene content on 1,2-vinyl formation in styrene-butadiene copolymerization
The presence of styrene in copolymerization results in less 1,2-vinyl content
than BD homopolymerization due to steric effect between allylic chain end
and styrene unit.
Cyclization of polybutadiene
High 1,2-vinyl


Propagation
+
TMEDA
Monomer starving condition
Batch vs. Continuous
Monomer feed rate
Cyclization
or
Vinyl cyclopentane
Divinyl cyclohexane
G. Quack and L. J. Fetters, Macromolecules, 11, 369 (1978).
Effect of monomer feed rate
100
1,2-vinyl (%)


Linear polybutadiene
Lewis base
Reaction temperature
80
60
Total 1,2-vinyl
40
Cyclic vinyl
20
0
0
2
4
6
Monomer feed rate (g/min)
Cyclization is favorable in monomer starved reaction condition
Cyclization consumes 1,2-vinyl
Cyclization of polybutadiene (continuous system)
Effect of reaction temperature
100
100
80
80
60
Total 1,2-vinyl
Cyclic vinyl
40
1,2-vinyl (%)
1,2-vinyl (%)
Effect of polar additive
1,2-vinyl
40
20
20
0
0
0
2
4
Polar additive/NBL
6
8
Total 1,2-vinyl
60
Cyclic vinyl
30
50
70
Temperature (c)
Cyclization reaction increases as
 polar additive amount increases (higher 1,2-vinyl)
 reaction temperature increases (Ea cyclization>Ea propagation)
90
Cyclization of polybutadiene
Effect of cyclic vinyl on T g
Total 1,2-vinyl
Cyclic vinyl
76
18
76
26
77
29
-10
15
20
25
30
Tg (°C)
-14
-18
-22
-26
Cyclic vinyl (%)
Effect of cyclic vinyl on viscosity
Stiff structure increases Tg
Logh ~
Cyclic vinyl has more
impact on the physical
properties than 1,2-vinyl
Viscosity @45 (cps)
160,000
(T-Tg)-1
120,000
80,000
40,000
0
15
20
25
Cyclic vinyl (%)
30
Macrostructure
Molecular weight
(gram of monomer/moles of initiator)
Molecular weight distribution (Ki >Kp, Xw/Xn=1+1/Xn)
Branched structure (linking reaction and transmetallation)
Chain transfer reaction
1) Initiation and chain transfer
R'
RLi +
Promoter
R
Li
R
toluene
+ PhCH2Li
R'=H or CH3
2) Propagation
R'
R'
nBD
PhCH2
PhCH2Li +
Li
R'
PhCH2
3) chain transfer
R'
PhCH2
Li
R'
PhCH3
n+1
PhCH2
H
+
PhCH2Li
n+1
Ea chain transfer > Ea propagation
 thermodynamic control
 kinetic control
Not applicable for functionalized polymer
Cost reduction of liquid polymer production
Li
n+1
Chain transfer reaction
265.45
Response
212.36
Mn calculated: 6,830
Mn measured : 6,120 PI: 1.57
159.27
106.18
Mn calculated: 17,750
Mn measured : 1,830 PI: 3.54
53.09
0.00
-53.09
11.8
14.1
16.5
18.8
21.1
23.4
Minutes
Chain transfer reaction in lithium initiated anionic polymerization increases as
 size of counter ion increases (Li < Na <K )
 polar additive amount increases (Li)
 reaction temperature increases (Ea chain transfer >Ea propagation)
 monomer feed rate decreases
and
 chain transfer reaction is maximized in pure toluene
Branched polymer
[h]b < [h]l

# of branch

Length of branch

MW of backbone

Type of branch (star, graft and hyper branched)
Reduction in melt and solution viscosities
Processing benefits, applications
Branched polymers by linking reactions
Chlorosilane
SiCl4 + 4 PLi
SiP4 + 4LiCl
Divinylbenzene
*
* * **
* ** * *
+
* = reactive chain end
Epoxy and silanol compounds
P-OH
PLi +
OH
OH
OH
OH
Quirk and Zhou US patent 7,235,615
OH
OH OH
DVB core
Functionalization
Chain end functionalization
Post polymerization modification
(Functional groups are randomly distributed on polymer backbone)
Chain end functionalization
Functional agent
O
H3O
PCH2CH2OH
PLi +
CO2
H3O
PCOOH
Protected functional initiator or agent
- or w-functionalized polymer by deprotection
Difunctional initiator
O
Na
H3O
HO-PB-OH (HTPB)
n BD
CO2
H3O
HOOC-PB-COOH
(CTPB)
Post polymerization modification
Hydrogenation (thermal stability and copolymer)
CH3
CH2 C
CH CH2
CH3
H2
Polyisoprene
1,2 > 1,4
CH2 CH CH2 CH2 n
n
Poly(ethylen-co-propylene)
Epoxidation
O
RCO3H
x
y
x-z
y
z
1,4 > 1,2
Maleinization
H
O
O
O
O
O
O
• Esterification
• Addition of acryl group
• Imidization
1,4 > 1,2
Structure-Property Relationships
Molecular weight
Properties that depend on chain ends
Properties that depend on entanglement
Molecular weight effect
Molecular weight
Entanglement
Intermolecular interaction
Number of end groups
Mw
Mn
Melt viscosity
h=KMwa
Izod impact resistance
Tensile strength
Flexural modulus
Tg and Tm
Viscosity
Macrostructural (MW) effect
10
h0=KMwP
9
8
High MW
Shear thinning
Broad MWD
Log h 0
Log ha
7
6
P=3.4
5
4
3
Newtonian Region
P=1
2
Low MW
1
0
0
1
2
3
3
.
3.5
Mcr
4
4.5
5
5.5
6
Log Mw
Log shear rate ()
J. T. Gruver and G. Kraus, J. Polym. Sci. Part A, 2, 797 (1964)
Random coils
Oriented coils
Mcr
Polybutadiene: 6,000
Polyisoprene: 10,000
Viscosity
Microstructural effect
90000
LVPB
80000
HVPB
SBR
Viscosity (cps)
70000
60000
50000
40000
30000
20000
10000
0
0
1000
2000
3000
4000
5000
6000
7000
8000
9000
10000
Mn (g/mole)
Zero shear viscosity data (Brookfield) as a function of both molecular weight and
microstructure using a series of commercially available liquid polydiene grades
( low vinyl polybutadiene,  high vinyl polybutadiene,  poly(butadiene-costyrene).
Viscosity of liquid polydiene is dependant on MW as well as
microstructure:
high vinyl polybutadienes > SBR copolymers > low vinyl polybutadienes
Viscosity
Functional group effect on chain end functionalized PB
Viscosity at 25 deg C (cP)
35000
Non-fun
30000
Fun
25000
20000
15000
10000
5000
0
0
1000
2000
3000
Mn (g/mole)
4000
5000
6000
Glass transition temperature
Tg = Tg() - (A/Mn)
0
-40
-10
5200
4700
-30
-50
2900
Tg (deg C)
Tg (deg C)
-20
-40
3900
-50
1800
-60
3900
-70
1400
8000
4500
2500
-80
-90
20
-70
-80
-100
0
-60
40
60
80
100
Vinyl (%)
Tg as a function of vinyl content and molecular weight for a series of
commercially available liquid polybutadienes.
-90
0
20
40
60
80
100
Amount of isoprene (%)
Tg as a function of comonomer content for a series of butadieneisoprene copolymers.
Glass transition temperature
Functional group effect
O
RCO3H
x
y
x-z
z
y
-60
Tg (deg C)
-65
-70
-75
-80
-85
-90
0
1
2
3
4
5
6
Oxiran (%)
Tg as a function of oxiran content for a series epoxidized liquid polybutadienes.
Crosslinking
H
Microstructure (1,2- vs. 1,4)
C
H
H
C
H
C
H
C
H2
C
H
C
H2
C
CH
H
H2C
Macrostructure
Sulfur crosslinking
Molecular weight dependency of crosslinking rate of polyisoprene
Mc of diene elastomers: ~ 12,000 g/mol
Liquid polydienes do not form elastically effective crosslinks
Mizuho Maeda, RubberChem 2006
Applications
Functional additives
Low viscosity (processing)
Similar chemical properties of elastomers (vulcanization)
Outstanding properties (High thermal stability, good moisture and chemical
resistance, good adhesive characteristics and excellent electrical
properties)
Unfunctionalized liquid polydienes
Processing aids
Low viscosity, non-toxic, low volatility and no bleeding (miscible with rubbers and nonextractable)
Coagents
1,2-polybutadiene for peroxide cure of elastomers
Wire and cable applications (better heat aging, fluid resistance and electrical properties)
Engineering rubber products (belts, hoses, gaskets and rollers)
Coating and potting agents
Autoxidation with baking or metallic driers (high level of unsaturation)
Tire application
HVPB and SBR: wet traction
LVPB: wear, low temperature properties
Functionalized liquid polydienes
Propellant binder: HTPB and CTPB
Adhesion promoters: Maleinized PB
Polyurethanes: HTPB
Epoxy resin modification: HTPB and CTPB
UV curing: Deoxidized, acrylated PB
Nanocomposite
Polymer-filler interaction
Summary
The microstructure and macrostructure affect the Tg and bulk viscosity
of final diene resin products.
Lithium-based anionic polymerization provides liquid polydienes with a
variety of microstructure and macrostructure including
functionalization.
The unique characteristics of liquid polydiene products has led to their
utility in a wide variety of markets and applications such as functional
additives for rubber and other thermosets, modification of
thermoplastics, adhesives, and coatings.
Adhesion Potential - Metal
Lap Shear Adhesion (psi)
5 phr coagent
2000
Brass
1600
Steel
1200
800
400
0
EPDM, Peroxide cure
Control
Ricobond
1731
LVPB-MA
HVPB-MA
Ricobond
1756
PB-MA adhesion promoters increase adhesive bond strength
Thermoplastic polyurethanes
HTPB / Diisocyanate / Diol chain extender
PU hard
domains
elastomeric
soft segment
T < Tsoftening
T > Tsoftening
Melt Flow
Vulcanizate
Adhering a Urethane component to a Rubber Compound substrate


Diene-segments interpenetrate and co-cure with rubber compound
Urethane segments bond to similar structure in PU
Functional Additive to a traditional Rubber Compound



varied loading increases impact on physical properties
impart modulus while minimizing hysteresis (vs. TPE)
realize advantages from phase structure at higher loading
Nanocomposite
+
Layered clay
Intercalated nanocomposite
Polymer
Exfoliated nanocomposite
An organophilic clay can be produced from a normally hydrophilic clay by ion exchange with an organic
cation such as an alkylammonium ion. For example, in montmorillonite, the sodium ions in the clay can
be exchanged for an amino acid such as 12-aminododecanoic acid (ADA):
Na+-CLAY + HO2C-R-NH3+Cl- .HO2C-R-NH3+-CLAY + NaCl
Mechanical and thermal properties
Permeability
Flame retardance
UV resistance