Polymer (PE) synthesis - scaling up to industrial scale

Polymer (PE) synthesis

Dr. Christophe Detrembleur

Center for Education and Research on Macromolecules (CERM)

University of Liège, Sart-Tilman B6a

Plan

1- Controlled radical polymerization vs conventional radical polymerization

2- 1

st

_{CRP mechanism: Reversible Termination}

3- 2

nd

_{CRP mechanism: Atom Transfer Radical Polymerization}

Classical radical polymerization

Classical radical polymerization

O O O O T O O 2 CH₃ C CH₃ NC N N C CH₃ CH₃ CN T CH₃ C CH₃ NC 2

Some free-radical initiators (R-R):

R-R 2 R

R

CH

₂

-CHY

T or UV

R

+ CH

₂

=CHY

1- Initiation

R

CH

₂

-CH

Y

n CH

₂

=CHY

R

CH

₂

-CH-CH

₂

-CH

Y

n

Y

2- Propagation

R

CH

₂

-CH-CH

₂

-CH

R

CH

₂

-CH-CH

₂

-CH

-

CH-CH

₂

-CH-CH

₂

-

R

n

2

n n

+

Y

Y

Y

Y

Y

Y

R

CH

₂

-CH-CH

₂

-CH

n

2

Y

Y

R

CH

₂

-CH-CH

₂

-CH

₂ n

Y

Y

R

CH

₂

-CH-CH

₂

=CH

n

Y

Y

3- Terminations

Benzoyl peroxide (BPO) Azobisisobutyronitrile (AIBN)

Classical radical polymerization

Classical radical polymerization

Some free-radical initiators (R-R):

R-R 2 R

R

CH

₂

-CHY

T or UV

R

+ CH

₂

=CHY

1- Initiation

R

CH

₂

-CH

Y

n CH

₂

=CHY

R

CH

₂

-CH-CH

₂

-CH

Y

n

Y

2- Propagation

R

CH

₂

-CH-CH

₂

-CH

R

CH

₂

-CH-CH

₂

-CH

-

CH-CH

₂

-CH-CH

₂

-

R

n

2

n n

+

Y

Y

Y

Y

Y

Y

R

CH

₂

-CH-CH

₂

-CH

n

2

Y

Y

R

CH

₂

-CH-CH

₂

-CH

₂ n

Y

Y

R

CH

₂

-CH-CH

₂

=CH

n

Y

Y

3- Terminations

Importance of the

Importance of the

«

«

classical

classical

»

»

radical polymerization

radical polymerization

Radical polymerization is

tolerant towards numerous functions

(-COOH, -OH, -NH₂,…).

applicable to a broad range of vinyl monomers
can be applied to aqueous media (suspension,

emulsion, miniemulsion)

highly reproducible (tolerant to impurities)

H

₂

C CH

S

polymérisation

radicalaire

-CH

₂

-CH-: substituent radical polymerization

Cl

CN

n

n

poly(ethylene)

poly(vinyl chloride)

n

poly(styrene)

n

poly(acrylonitrile)

Some examples of polymers produced by this technique: n

Controlled radical polymerization

Controlled radical polymerization

+

Conventional radical polymerization

Controlled radical polymerization

1- Initiation

2- Propagation : v_p = k_p [P°] [M]

3- Occurrence of irreversible termination reactions: v_t= k_t [P°]2

NO irreversible termination reactions, only initiation and propagation.

How to avoid the occurrence of irreversible termination reaction ? [P°] has to decrease →v_p/v_t ⇑⇑⇑⇑

Dormant species Active

Criteria for a controlled radical polymerization

Mn = ([M]

₀

/[I]

₀

) × Mw(M) × conv

= (m

_M

/n

_I

) × conv

M

n

(

g

/m

o

l)

Conversion (%)

5000 10000 15000 20000 20 40 60 80 100 25000 30000

1- Control of the molecular weight

[M]₀ = monomer concentration at the initial stage [I]₀ = initiator concentration at the initial stage Mw(M) = molecular weight of the monomer

Criteria for a controlled radical polymerization

Mn = ([M]

₀

/[I]

₀

) × Mw(M) × conv

= (m

_M

/n

_I

) × conv

M

n

(

g

/m

o

l)

Conversion (%)

5000 10000 15000 20000 20 40 60 80 100 25000 30000

Criteria for a controlled radical polymerization

Mn = ([M]

₀

/[I]

₀

) × Mw(M) × conv

= (m

_M

/n

_I

) × conv

M

n

(

g

/m

o

l)

Conversion (%)

5000 10000 15000 20000 20 40 60 80 100 25000 30000

Criteria for a controlled radical polymerization

Mn = ([M]

₀

/[I]

₀

) × Mw(M) × conv

= (m

_M

/n

_I

) × conv

M

n

(

g

/m

o

l)

Conversion (%)

5000 10000 15000 20000 20 40 60 80 100 25000 30000

Criteria for a controlled radical polymerization

Mn = ([M]

₀

/[I]

₀

) × Mw(M) × conv

= (m

_M

/n

_I

) × conv

M

n

(

g

/m

o

l)

Conversion (%)

5000 10000 15000 20000 20 40 60 80 100 25000 30000

Criteria for a controlled radical polymerization

Mn = ([M]

₀

/[I]

₀

) × Mw(M) × conv

= (m

_M

/n

_I

) × conv

M

n

(

g

/m

o

l)

Conversion (%)

5000 10000 15000 20000 20 40 60 80 100 25000 30000

Criteria for a controlled radical polymerization

M

n

(

g

/m

o

l)

Conversion (%)

5000 10000 15000 20000 20 40 60 80 100 25000 30000

2- Resumption of the polymer chains

Criteria for a controlled radical polymerization

M

n

(

g

/m

o

l)

Conversion (%)

5000 10000 15000 20000 20 40 60 80 100 25000 30000

2- Resumption of the polymer chains

T

At the end of the polymerization, the chains are end-capped by the controlling agent ⇒ The chains can be reactivated and initiate the polymerization of a vinyl monomer

Criteria for a controlled radical polymerization

M

n

(

g

/m

o

l)

Conversion (%)

5000 10000 15000 20000 20 40 60 80 100 25000 30000

2- Resumption of the polymer chains

Criteria for a controlled radical polymerization

M

n

(

g

/m

o

l)

Conversion (%)

5000 10000 15000 20000 20 40 60 80 100 25000 30000

2- Resumption of the polymer chains

Criteria for a controlled radical polymerization

M

n

(

g

/m

o

l)

Conversion (%)

5000 10000 15000 20000 20 40 60 80 100 25000 30000

Criteria for a controlled radical polymerization

M

n

(

g

/m

o

l)

Conversion (%)

5000 10000 15000 20000 20 40 60 80 100 25000 30000

Criteria for a controlled radical polymerization

L

n

([

M

]0

/[

M

])

)

Time (hr)

0.2 0.4 0.6 0.8 1 2 3 4 5 1.0 1.2

3- Kinetics is first order in monomer

6 7 8

V

_p

= -d[M]/dt = k

_p

× [M] × [P°]

By integration of v

_p

:

Criteria for a controlled radical polymerization

L

n

([

M

]

0

/[

M

])

)

Time (hr)

0.2 0.4 0.6 0.8 1 2 3 4 5 1.0 1.2

3- Kinetics is first order in monomer

6 7 8

V

_p

= -d[M]/dt = k

_p

× [M] × [P°]

By integration of v

_p

:

Ln([M]

₀

/[M]) = k

_p

× [P°] × t

Polydispersity: a criterium for CRP ?

Polydispersity = Mw/Mn = size distribution of the polymer chains.

For most of living and controlled polymerization processes, Mw/Mn →→→→ 1. If Mw/Mn = 1: all the polymer chains have the same length.

Mw/Mn →1: ONLY if the initiation rate is faster than the propagation rate !! A narrow polydispersity is NOT a criterium for « livingness » !!

M V 0.00 20.00 40.00 60.00 80.00 100.00 120.00 140.00 160.00 Minutes 10.00 12.00 14.00 16.00 18.00 20.00 22.00 24.00 26.00 28.00 30.00 32.00 34.00 36.00 Mn ↑

CRP: a way to the macromolecular engineering

Homopolymer

Statistical copolymer

Alternated copolymer

Block copolymer

_{Star-shaped (co)polymer}

Grafted (co)polymer

Gradient copolymer

1- Control of Mn Mn =

([M]₀/[I]₀) × Mw(M) × conv.

2- Control of the copolymer composition

3- Control of the architecture

CRP: a way to the macromolecular engineering

Homopolymer

Statistical copolymer

Alternated copolymer

Block copolymer

_{Star-shaped (co)polymer}

Grafted (co)polymer

Gradient copolymer

1- Control of Mn Mn =

([M]₀/[I]₀) × Mw(M) × conv.

2- Control of the copolymer composition

3- Control of the architecture

CRP: a way to the macromolecular engineering

Homopolymer

Statistical copolymer

Alternated copolymer

Block copolymer

_{Star-shaped (co)polymer}

Grafted (co)polymer

Gradient copolymer

1- Control of Mn Mn =

([M]₀/[I]₀) × Mw(M) × conv.

2- Control of the copolymer composition

3- Control of the architecture

CRP: a way to the macromolecular engineering

Homopolymer

Statistical copolymer

Alternated copolymer

Block copolymer

_{Star-shaped (co)polymer}

Grafted (co)polymer

Gradient copolymer

1- Control of Mn Mn =

([M]₀/[I]₀) × Mw(M) × conv.

2- Control of the copolymer composition

3- Control of the architecture

CRP: a way to the macromolecular engineering

Homopolymer

Statistical copolymer

Alternated copolymer

Block copolymer

_{Star-shaped (co)polymer}

Grafted (co)polymer

Gradient copolymer

1- Control of Mn Mn =

([M]₀/[I]₀) × Mw(M) × conv.

2- Control of the copolymer composition

3- Control of the architecture

CRP: a way to the macromolecular engineering

Homopolymer

Statistical copolymer

Alternated copolymer

Block copolymer

_{Star-shaped (co)polymer}

Grafted (co)polymer

Gradient copolymer

1- Control of Mn Mn =

([M]₀/[I]₀) × Mw(M) × conv.

2- Control of the copolymer composition

3- Control of the architecture

Macromolecular engineering by CRP

Macromolecular engineering by CRP

Homopolymer Block copolymer Random copolymer Gradient copolymer

Graft copolymer

A_n star-shaped polymer AnBm star-shaped

copolymer A₂B star-shaped copolymer ABC star-shaped copolymer More complex architectures:

X

P

_n

P

_n

k

_act

k

_deact

+

X

+M

k

_p

O

N

R

R'

nitroxide radicals

R = Ph, CN, CO

₂

Me,...

Ph

C

R

Ph

di- or triarylmethyl radicals

B

O

borinate radical

N

N

N

N

Ph

Ph

Ph

verdazyl radicals

N

N

N

Ph

Ph

Ph

Ph

triazolinyl radicals

(TMP)Co

organocobalt porphyrin

complexes

1st CRP mechanism: reversible termination

1st CRP mechanism: reversible termination

Co(acac)

₂

The Nitroxide-Mediated Radical Polymerization (NMP)

+

O N

R

R'

O N

R

R'

nitroxide

Two main approaches for NMP:

Bimolecular system:

free radical initiator + nitroxide

N O O O O O

+

BPO TEMPO alkoxyamine

The Nitroxide-Mediated Radical Polymerization (NMP)

+

O N

R

R'

O N

R

R'

nitroxide

Two main approaches for NMP:

Bimolecular system:

free radical initiator + nitroxide

N O O O O O

+

BPO TEMPO N O O O N O O O N O O O n T > 100°C Styrene 95°C, 3.5h alkoxyamine Styrene alkoxyamine [TEMPO/BPO] ≈ 1.2

The Nitroxide-Mediated Radical Polymerization (NMP)

+

O N

R

R'

O N

R

R'

nitroxide

Two main approaches for NMP:

Bimolecular system:

free radical initiator + nitroxide

N O O O O O

+

BPO TEMPO

Unimolecular system: use of alkoxyamines

N O O O T N O O O initiator nitroxide alkoxyamine

>100oC O O _O N O N O O O N O O n Alkoxyamine

Unimolecular system

Unimolecular system

=

Initiator and control agent Advantage of the unimolecular system:

⇒ improved initiator efficiency

⇒ control of the chain-ends structure

Hawker et al. J. Am. Chem. Soc. 1994, 116, 11185 Molecular weight calculation:

M_{n, th.} = × MW_M × conv = (m_M/n_Alk) × conv

where m_M is the weight (g) of monomer; and n_Alkis the moles number of alkoxyamine

[M]₀ [Alk]₀

N O R R' P_{n +} k_act k_deact N O R R' P_n

R and R’ govern the stability and reactivity of the nitroxide, but also k_deact et k_act, and consequently, the equilibrium active/dormant species.

Importance of the nitroxide structure

Importance of the nitroxide structure

Some important nitroxides active in NMP:

O N + n 120oC Ph O N Ph Ph n

Polymerization time: 4-18 h

M

_n

controlled up to 200000 g/mol

M

_n,exp

≈

M

_n,th

M

_w

/M

_n

: < 1.1 until Mn ~ 75000 g/mol and

1.2-1.25 until Mn ~ 200000 g/mol

Styrene polymerization

Ph O N Ph + n CO₂Bu O N Ph Ph O CO₂Bu N Ph n 123oC + n 120oC CO₂Bu Ph O N Ph

Poor control

(fast polymerization and

M

_w

/M

_n

≈

1.5-2.2).

1 eq.

0.05 eq.

Polymerization time : 16h at 123oC et 48h at 95-100oC. M_n until 150000 g/mol M_n,exp ≈ M_n,th M_w/M_n : ≈ 1.05-1.30

A slight excess of free nitroxide is needed !

How to improve the control ?

Butyl acrylate polymerization

Monomers

- styrenes, acrylates, acrylonitrile, (meth)acrylic acid, isoprene,…

- NMP inefficient with vinyl chloride, vinyl acetate (and methacrylates)

Solvents

- Most often, the polymerizations are carried out in the bulk (T > 100°C) - Non polar solvents (xylene, toluene,…) with a low transfer constant. - Aqueous media (suspension, miniemulsion, emulsion)

O

O R _O O_R

CN OH

O styrene acrylate methacrylate acrylonitrile acrylic acid

where R = N O n OH Cl O O vinyl chloride vinyl acetate

Monomers and solvents

Monomers and solvents

isoprene

O

O R

SG1 based alkoxyamines

SG1 based alkoxyamines

Efficient for styrene and acrylate polymerizations without the use of excess nitroxides

⇒

_{preparation of}

Dispersion

Bad pigment dispersion Good pigment dispersion

Use of polyelectrolytes

(polyphosphates, poly(carboxylic acids),…)

Electrostatic stabilisation _{Steric stabilisation}

Utilisation de (co)polymères

Application: pigments stabilization

Application: pigments stabilization

Application: pigments stabilization

CO₂Bu R O R O N R' R'' n + 130°C N R' R'' COn₂Bu O O N m 130°C O N R' R'' m R CO₂Bu O O N n pigment

Emulsion polymerization without any surfactant

Emulsion polymerization without any surfactant

MONAMS N O CH P O O O C H CH₃ C O H₃CO _COOH SG1, 130°C, dioxane n N CH P O O O C H CH₃ C O H₃CO C H C O COOHn H H _{n = 21} Mw/Mn = 1.17 1- Preparation of PAA ChemComm 2005, 5, 614

Emulsion polymerization without any surfactant

Emulsion polymerization without any surfactant

MONAMS N O CH P O O O C H CH₃ C O H₃CO _COOH SG1, 130°C, dioxane n N CH P O O O C H CH₃ C O H₃CO C H C O COOHn H H _{n = 21} Mw/Mn = 1.17 1- Preparation of PAA 2- Preparation of PAA-b-PS (and PAA-b-PnBuA) in emulsion

ChemComm 2005, 5, 614 N CH P O O O C H CH₃ C O H₃CO C H C O COOHn H H _{styrène, 120°C} eau, NaOH N CH P O O O C H CH₃ C O H₃CO C H C O COOn -Na+ H H C HC Ph H m H

Emulsion polymerization without any surfactant

Emulsion polymerization without any surfactant

MONAMS N O CH P O O O C H CH₃ C O H₃CO _COOH SG1, 130°C, dioxane n N CH P O O O C H CH₃ C O H₃CO C H C O COOHn H H _{n = 21} Mw/Mn = 1.17 1- Preparation of PAA 2- Preparation of PAA-b-PS (and PAA-b-PnBuA) in emulsion

ChemComm 2005, 5, 614 N CH P O O O C H CH₃ C O H₃CO C H C O COOHn H H _{styrène, 120°C} eau, NaOH N CH P O O O C H CH₃ C O H₃CO C H C O COOn -Na+ H H C HC Ph H m H

Emulsion polymerization without any surfactant

Emulsion polymerization without any surfactant

MONAMS N O CH P O O O C H CH₃ C O H₃CO _COOH SG1, 130°C, dioxane n N CH P O O O C H CH₃ C O H₃CO C H C O COOHn H H _{n = 21} Mw/Mn = 1.17 1- Preparation of PAA 2- Preparation of PAA-b-PS (and PAA-b-PnBuA) in emulsion

♦ Styrène;

•

nBuA ChemComm 2005, 5, 614 N CH P O O O C H CH₃ C O H₃CO C H C O COOHn H H _{styrène, 120°C} eau, NaOH N CH P O O O C H CH₃ C O H₃CO C H C O COOn -Na+ H H C HC Ph H m H

X

P

_n

P

_n

k

_act

k

_deact

+

+M

k

_p

+ M

_t

M

_t

X

N N _N N Cu X PPh₃ Ru Cl PPh₃ Cl PPh₃ Br Ni Br PPh3 PPh₃ Br Fe X PPh3 PPh₃ PPh₃ Pd PPh₃ PPh3 PPh₃ PPh₃ Rh Cl Ph₃P PPh₃ PPh₃ Re PPh₃ O I O NMe₂ NMe₂ Ni Br Ru Cl PPh₃ PPh₃ (X = Cl, Br) Cu(I) Ru(II) Ni(II) Fe(II) Pd(0) Rh(I) Re(V) Ni(II) Ru(II)

2

2

ndnd

_{CRP mechanism: Atom Transfer Radical Polymerization}

_{CRP mechanism: Atom Transfer Radical Polymerization}

R-X R Mtn Mtn+1X Y R Y R Y X k_act k_ad k_deact Mtn Mtn+1X R Y Y k_p n R Y R Y X

Overall reaction:

R

-

X

+ n CH

₂

=CHY

Mt

R

-(CH

₂

-CHY)

_n

-

X

n

Atom Transfer Radical Polymerization (ATRP)

Atom Transfer Radical Polymerization (ATRP)

How to carry out an ATRP experiment ?

R-X + Mt + ligand + monomer

→

ATRP

ATRP initiators

ATRP initiators

ATRP initiators = activated halogenoalcanes: α-haloketones, α-haloesters, α-nitriles, sulfonyl chlorides,…

Generally, use of initiators which mimic the structure of the dormant chains:

Molecular weight calculation:

M_{n, th.} = × MW_M × conv = (m_M/n_RX) × conv

where m_M is the weight (g) of monomer; and n_RX is the moles number of initiator

[M]₀ [RX]₀

Br HO O Br O O Br O O O O Br O O Br H₂N O O Br O N NH O O HO _OH O O Br O HO _OH N N N N NH₂

Some ATRP functional initiators

Ligands for ATRP

Ligands for ATRP

Role of the ligands

1- Metal solubilisation in organic media

2- Adjusting the position and dynamics of the active/dormant species equilibrium

Types of ligands

Cu: bipyridines, iminopyridines, polyamines Ru: triarylphosphines, carbènes

Ni: triarylphosphine, Granel

Fe: trialkylphosphine, trialkylamine

X Pn Pn k_act k_deact + +M k_p + M_t M_t X NMe₂ NMe₂ Br P Ligands for CuI

Ligands for ATRP

Ligands for ATRP

X Pn Pn k_act k_deact + +M k_p + M_t M_t X

Some important Cu

I

_{(CuBr et CuCl) complexes}

…and Cu

II

_(CuBr

2

et CuCl

2

) complexes

Cu(I)/Ligand molar

ω

ω

-

-

chain end functionalization

chain end functionalization

Monomers and solvents

Monomers and solvents

Monomers

- styrenes, acrylates, methacrylates, acrylonitrile, (meth)acrylic acid,…

- ATRP inefficient with vinyl chloride, vinyl acetate and dienes because the radical is too reactive and poorly stabilized ⇒ C-X bond at the ω-chain-end is too stable.

Solvents

- Most often, the polymerizations are carried out in the bulk

- Non polar solvents (xylene, toluene,…) with a low transfer constant. - Aqueous media (suspension, miniemulsion, emulsion)

- Alcohols

O

O R _O O_R

CN OH

O styrene acrylate methacrylate acrylonitrile acrylic acid

where R = N O n OH Cl O O vinyl chloride

Halogen exchange in ATRP

Halogen exchange in ATRP

ATRP nBuA CO2Et CO₂Et CO₂Bu Br Br CO₂Bu n n n ATRP MMA CO₂Et CO₂Et CO₂Bu CO₂Bu n n _CO 2Me X m X CO₂Me m Br-PnBuA-Br X-PMMA-PnBuA-PMMA-X

For preparing such copolymer, the halogen exchange is required.

CO₂Et CO₂Et CO₂Bu Br Br CO₂Bu n n n ATRP MMA CO2Et CO₂Et CO₂Bu CO₂Bu n n _CO 2Me X m X CO₂Me m Conditions: toluene, 85°C, [MMA] = 4.67M, [Br-PnBuA-Br] = 4mM, [catalyseur] = 4mM

Halogen exchange in ATRP

Why is this halogen exchange useful ?

Without halogen exchange, MMA propagation is fast compared to initiation. Unreacted macroinitiator will thus be left at the end of the MMA polymerization.

With halogen exchange (Cl in place of Br), MMA propagation is decreased because C-Cl bond at the ω -chain end of PMMA is more stable than the C-Br bond. Initiation would thus be favoured compared to propagation.

CuBr

-Cl

CuCl (+CuCl₂)

Halogen exchange in ATRP

Halogen exchange in ATRP

X Pn Pn k_act k_deact + +M k_p + M_t M_t X

Preparation of hydrosoluble block copolymers

Preparation of hydrosoluble block copolymers

PEO-b-PMADAME O O H₃C O n O Cl O O N m O O H₃C O n O Cl O O N m _Br EtBr

Preparation of hydrosoluble block copolymers

Preparation of hydrosoluble block copolymers

O O H₃C OH n Br O Br NEt₃ PEO-OH O O H₃C O n O Br O O N m CuCl/CuCl₂ HMTETA 50°C O O H₃C O n O Cl O O N m O O H₃C O n O Cl O O N m _Br EtBr PEO-b-PMADAME

Antibacterial copolymers

Antibacterial copolymers

CH₂ C CH₃ O O CH₂ CH₂ N C H₃ CH3 n CH2 C CH₃ O O CH₂ CH₂ N+ n C H₃ CH₃CH2 CH2 6CH3 Br Br CH_{2 7}CH₃ Quaternized

Quaternized poly(DMAEMA)poly(DMAEMA)

CH₂ C CH₃ O O CH₂ CH₂ NH n C C H₃ CH₃CH3 Poly(

Poly(TBAEMA)TBAEMA)

Antibacterial copolymers for LDPE

Antibacterial copolymers for LDPE

PEB O C O C CH₃ CH₃ C H₂ CH CH₃ C O O C H₂ C H₂ N H n C CH₃ CH₃ CH₃ C H₂ C H CH₂ CH₃ C H₂ CH₂ CH₂ HC₂ CH₂ CH₂ O n m C O C CH₃ CH₃ Br C H₂ C C O O C H₂ CH₂ NH C CH₃ CH₃ CH₃ CH₃ PEB-Br TBAEMA PTBAEMA

PEB-b-Miscible with LDPE

⇒ Anchoring block to the LDPE

matrix

Antibacterial block CuCl, HMTETA Toluene

Antibacterial testings of LDPE bottels containing PEB

Antibacterial testings of LDPE bottels containing PEB

-

-

b

b

-

-

PTBAEMA

PTBAEMA

Control: LDPE, 4g, 0.5 cm × 0.5 cm pieces Antibacterial LDPE: LDPE+ 10 % PEB-b-PTBAEMA, 4 g, 0.5 cm × 0.5 cm pieces 3g, 0.5 cm × 0.5 cm pieces 2g, 0.5 cm × 0.5 cm pieces Time (min) 0 20 40 60 80 100 120 140 lo g (s u rv iv o rs ) (c e lls /m l) 0 2 4 6 8 10 LDPE (4g) LDPE + 10wt% PEB-b-PTBAEMA (2g) LDPE + 10wt% PEB-b-PTBAEMA (3g) LDPE + 10wt% PEB-b-PTBAEMA (4g) TEM images Image SEM Biomacromolecules 2006, 7(8), 2291-2296

Polymer/biomolecules biohybrides

Polymer/biomolecules biohybrides

Chem. Comm. 2004, 2026

6-7 polymer chains grafted onto lysozome

X

P

_m

P

_m

k

_act

k

_deact

+M

k

_p

P

_n

₊

P

_n

X

+

CH

₃

I

1-phenyl ethyl iodide

S

C

Z

S

R

thiocarbonylthio compounds

Z = Ph

R = CH

₂

Ph

3

3

rdrd

_{mechanism: degenerative transfert (DT)}

_{mechanism: degenerative transfert (DT)}

An atom or group of atoms is rapidly and reversibly transfered from a dormant chain to an active chain. During this transfer, the dormant chain becomes active, and the active chain becomes dormant.

For the polymerization to be controlled, the transfer has to be fast compared to propagation ! Some exemples of DT reagents:

Activating group

Leaving group

(initiating group)

RAFT agent + free radical initiator + monomer

∆

RAFT

Only organic reagents

A wide range of monomers: methacrylates, acrylates, styrene, styrene sulfonate, vinyl benzoate,

2-hydroxyethyl methacrylate, acrylic acid, dimethylaminoethyl methacrylate, acrylamides, …

T: 60-100oC; polymerizations in bulk, solutions and aqueous (dispersed) media a Z = Ph, R = C(CH₃)₂Ph b Z = Ph, R = CH(CH₃)Ph c Z = Ph, R = CH₂Ph d Z = Ph, R = C(CH₃)(CN)CH₂CH₂CO₂Na e Z = Ph, R = C(CH₃)₂CN f Z = CH_3, R = CH₂Ph g Z = Ph, R = C(CH₃)(CN)CH₂CH₂CH₂OH h Z = Ph, R = C(CH₃)(CN)CH₂CH₂CO₂H

Reversible Addition

Reversible Addition

-

-

Fragmentation chain Transfer (RAFT)

Fragmentation chain Transfer (RAFT)

C

S

Z

S

R

How to carry out a RAFT experiment ?

I + M Pn P_n S C S R Z + P_n S C S R Z S P_n C S Z + R addition fragmentation R + M P_m initiation re-initiation P_m S C S P_n Z + P_m S C S P_n Z S P_m C S Z + P_n addition fragmentation + M + M 2 3 3 4 5 1

Overall process

Initiator + Monomer +

Z

C

S

S

R

R

P

_x

S

C

S

Z

RAFT mechanism

RAFT mechanism

1) Importance of Z and R groups

Z = activating group

⇒

has to activate the RAFT agent for the addition of radicals

R = leaving group

⇒

has to be a good leaving “radicalar” group in order to promote the fragmentation in the good direction

P_n S C S R Z + P_n S C S R Z addition 2 1 C S S R P_n Z S P_n C S Z + R fragmentation 2 3

2) Choice of the RAFT agent = f(monomer)

How to choose the RAFT agent ?

How to choose the RAFT agent ?

C

S

Methacrylates

S C Ph S C(CH₃)₂CN S C Ph S CN CH₃ CH₂CH₂CH₂OH CH₂ C CH₃ C OCH₃ O

Sterically hindered propagating radical with a moderate reactivity P_n S C S R Z + P_n S C S R Z S P_n C S Z + R addition fragmentation 2 3 1

Phenyl group Activated tertiary alkyl

group

In order to transform the active chain Pn° into dormant chain 3, the S-R bond (intermediate 2) has to break. If this S-R bond is too stable compared to S-P_n bond, the dormant species 3 will not form. No control will be observed.

How to choose the RAFT agent ?

Acrylates et acrylic acid

S C Ph S CH₂Ph S C S CH₂Ph N

Acrylamides

S C Ph S C(CH₃)₂Ph CH₂ C H C OR O

Low steric hindrance and high reactivity of the propagating radical

How to choose the RAFT agent ?

1- Monomers with similar reactivities

How to prepare block copolymers by RAFT ?

How to prepare block copolymers by RAFT ?

S C S Ph C(CH3)2Ph CO₂Bu AIBN Ph(H₃C)₂C CO₂Bu S C Ph S n CO₂Me AIBN Ph(H₃C)₂C CO₂Bu n S C S Ph CO₂Me m

S S Z A B + S S Z A B S S Z B + A

1- Monomers with similar reactivities

2- Monomers with different reactivities

How to prepare block copolymers by RAFT ?

How to prepare block copolymers by RAFT ?

S C S Ph C(CH3)2Ph CO₂Bu AIBN Ph(H₃C)₂C CO₂Bu S C Ph S n CO₂Me AIBN Ph(H₃C)₂C CO₂Bu n S C S Ph CO₂Me m S C S Ph C(CH3)2Ph Ph AIBN Ph(H₃C)₂C Ph S C Ph S n CO₂Me AIBN Ph(H₃C)₂C Ph n S C S Ph CO₂Me m Ph(H₃C)₂C CO₂Me S C Ph S n St AIBN Ph(H₃C)₂C CO₂Me n S C S Ph Ph m CO₂Me AIBN

S S Z A B + S S Z A B S S Z B + A

1- Monomers with similar reactivities

2- Monomers with different reactivities

How to prepare block copolymers by RAFT ?

How to prepare block copolymers by RAFT ?

S C S Ph C(CH3)2Ph CO₂Bu AIBN Ph(H₃C)₂C CO₂Bu S C Ph S n CO₂Me AIBN Ph(H₃C)₂C CO₂Bu n S C S Ph CO₂Me m S C S Ph C(CH3)2Ph Ph AIBN Ph(H₃C)₂C Ph S C Ph S n CO₂Me AIBN Ph(H₃C)₂C Ph n S C S Ph CO₂Me m Ph(H₃C)₂C CO₂Me S C Ph S n St AIBN Ph(H₃C)₂C CO₂Me n S C S Ph Ph m CO₂Me AIBN S S Z O O CH₃

S S Z A B + S S Z A B S S Z B + A

1- Monomers with similar reactivities

2- Monomers with different reactivities

How to prepare block copolymers by RAFT ?

How to prepare block copolymers by RAFT ?

S C S Ph C(CH3)2Ph CO₂Bu AIBN Ph(H₃C)₂C CO₂Bu S C Ph S n CO₂Me AIBN Ph(H₃C)₂C CO₂Bu n S C S Ph CO₂Me m S C S Ph C(CH3)2Ph Ph AIBN Ph(H₃C)₂C Ph S C Ph S n CO₂Me AIBN Ph(H₃C)₂C Ph n S C S Ph CO₂Me m Ph(H₃C)₂C CO₂Me S C Ph S n St AIBN Ph(H₃C)₂C CO₂Me n S C S Ph Ph m CO₂Me AIBN

Difunctional RAFT agent

Other architectures by RAFT

Other architectures by RAFT

S S S Ph Ph S S Ph S S S Ph AIBN AIBN S Ph S S S Ph

Other architectures by RAFT

Other architectures by RAFT

S Ph S S S Ph S S Ph S S Ph S Ph S S Ph S S S Ph S S Ph AIBN

RAFT agents et MADIX agents

RAFT agents et MADIX agents

End

End

-

-

functionalization of (co)polymers

functionalization of (co)polymers

S S O O MMA AIBN, 60°C, 8h S S O O CH₂ C CH₃ CO₂nCH₃ Toluene AIBN in excess 80°C, 2.5 h O O CH₂ C CH₃ CO₂nCH₃ CN Mn = 13500 Mw/Mn = 1.18

Mechanism of

ω

-chain end functionalization:

S S O O CH₂ C CH₃ CO₂CHn ₃ AIBN en excès S O O CH₂ C CH₃ CO₂CHn ₃ S CN O O CH₂ C CH₃ CO₂CHn-1₃ CH₂ C CH₃ CO₂CH₂ S S NC O O CH₂ C CH₃ CO₂CHn-1₃ CH₂ C CH₃ CO₂CH₃ CN + CN Macromolecules 2005, 38, 2033

MMA/ RAFT agent /AIBN = 500/1/0.1

End

Preparation of polyelectrolytes

Preparation of polyelectrolytes

Angew. Chem. Int. Ed. 2006, 45, 5792 S C S Ph CN COOH O HN 70°C, water O NH O HN HOOC CN n O HN S Ph S m S O HN HOOC CN n Ph S NH3+Cl -HOOC N N COOH CN CN HOOC N N COOH CN CN 70°C, water NH₃+Cl -NH₃+Cl

-Synthesis of PEO

Synthesis of PEO

-

-

b

b

-

-

PAA

PAA

CH₃O(CH₂CH₂O)₄₅CH₂CH₂OH HOOC-C-S-C-S-C₁₂H₂₅ CH₃ CH_{3 S} DCC PEO-OOC-C-PAA-S-C-S-C₁₂H₂₅ CH₃ CH_{3 S} [PEO-AR] AA / DMF CH₃O(CH₂CH₂O)₄₅CH₂CH₂-OOC-C-S-C-S-C₁₂H₂₅ CH₃ CH_{3 S} [PEO-AR] 80°C 1.16 83-45 PAA-PEO E21-2 1.19 48-45 PAA-PEO E21-1 IP (GPC) DP (NMR) Ligand CODE

Polymerization conditions : [RAFT agent] : [AIBN] = 40: 1 [AA] = 4 M in DMF at 80°C.

Synthesis of PAA

Synthesis of PAA

-

-

b

b

-

-

PAMPEO

PAMPEO

n CH₂=CH C=O HOOC-C-(CH₂-CH)_n-S-C-S-C₁₂H₂₅ C=O CH₃ CH₃ S C=O OH HOOC-C-(CH₂-CH)_n-(CH₂-CH)_m-S-C-S-C₁₂H₂₅ C=O PEO OCH₃ CH₃ CH₃ S AR, AIBN DMF, 80°C PAMPEO DMF, 80°C OH OH 1.30 34-66 PAA-PAMPEO E21-24 1.35 34-110 PAA-PAMPEO E21-23 1.51 61-21 PAA-PAMPEO E21-11 1.25 61-11 PAA-PAMPEO E21-10 IP(GPC) DP(RMN) Ligand CODE

Polymerization condition : [RAFT agent] : [AIBN] = 80: 1 [AMPEO] = 0.5 M in DMF at 80°C.

HOOC-C-S-C-S-C₁₂H₂₅ CH₃

CH_{3 S}

Application to coatings

Application to coatings

Advantages: - Control of Mn

- No free surfactant ⇒ no migration of surfactant out of the coating - Functionnalization of the latex particles possible

- No organic solvent _{Macromolecules 2005, 38, 2191}

1- Acrylic acid is polymerized in water (pH = 6) until DP ~ 5.

2- Butyl acrylate is slowly added in order to form amphiphilic PAA-b-PnBuA which forms micelles. Micelles are growing with the monomer conversion to form the latex.

Some criteria for the use of CRP at the industrial scale

Some criteria for the use of CRP at the industrial scale

Cheap CRP system

Cheap and readily available

starting products

Fast polymerization

Use of the existing reactors and lines

No purification and treatment of the final polymers

Same conditions as for conventional

technique

 Odorless polymers

 Colorless polymers

Polymers not contaminated by toxic residues