of 10
S1
Supporting Information
Stereocomplex Formation of Densely Grafted Brush Po
lymers
Benjamín R. Sveinbjörnsson
a
, Garret M. Miyake
a
, Amer ElBatta
b
, Robert H. Grubbs
a,
*
a
Division of Chemistry and Chemical Engineering, Cal
ifornia Institute of Technology,
1200 E. California Boulevard, Pasadena, California
91125, United States,
b
Department of
Chemistry, King Fahd University of Petroleum and Mi
nerals, Dhahran 31261, Saudi
Arabia
* To whom correspondence should be addressed at e-m
ail: rhg@caltech.edu
Table of Contents
1.
Experimental Procedures S2
2.
Supplementary Tables (S1) S5
3.
Supplementary Figures (S1S5) S6
4.
References S10
S2
1. Experimental Procedures
Materials
(H
2
IMes)(pyr)
2
(Cl)
2
RuCHPh
1
and
N
(hydroxyethanyl)
cis
5norbornene
exo
2,3di
carboximide,
2
were prepared as described previously. All solvent
s were purchased from
VWR or SigmaAldrich. Rutheniumbased metathesis ca
talyst was obtained from Materia
Inc. and stored in a drybox. D (+)Lactide was obta
ined from BOC Sciences while other
chemicals were bought from SigmaAldrich. Dry solve
nts were purified by passing them
through solvent purification columns. Lactide monom
ers were purified by sublimation
under vacuum. All other solvents and chemicals were
used without further purification
unless otherwise stated.
General information
1
H NMR
spectra were recorded at room temperature on a Vari
an Inova 500 (at 500 MHz).
The NMR spectra were analyzed on MestReNova softwar
e and are reported relative to
CDCl
3
(
δ
7.26). NMR abbreviations: s = singlet, d = doublet
, t = triplet, m = multiplet, br
= broad, dt = doublet of triblets.
Gel permeation chromatography (GPC)
was carried out in THF on two Plgel 10

m
mixedB LS columns (Polymer Laboratories) connected
in series with a miniDAWN
TREOS multiangle laser light scattering (MALLS) det
ector, a ViscoStar viscometer and
Optilab rex differential refractometer (all from Wy
att Technology). The d
n
/d
c
values
used for the poly(lactide) macromonomers were 0.050
.
Differential Scanning Calorimetry (DSC)
was performed on a PerkinElmer DSC 7.
Samples were heated to 125°C at 20°C/min, held at 2
5°C for 5 minutes and then cooled
to 20°C at 10°C/min. The temperature was held at 20
°C for 5 minutes before being
reheated to 250°C at 10°C to determine the melting
transition temperature. Finally, the
sample was cooled back to room temperature at 20°C/
min.
Optical rotations
were measured in a solution of chloroform with a J
asco P2000
polarimeter operating on a sodium Dline (589 nm)
at 25°C, using a 10 cm pathlength
cell.
S3
Synthesis
Representative procedure for the synthesis of Norbo
rnene-Poly(lactide) (
L
MM
-4)
The monomer,
L
Lactide (2.00 g, 13.9 mmol) was added to a 40 mL s
cintillation vial and
dissolved in 15 mL of dry THF. The initiator,
N
(hydroxyethanyl)
cis
5norbornene
exo

2,3dicarboximide (35.7 mg, 0.172 mmol, 1 equiv) a
nd the catalyst, 1,3
dimesitylimidazol2ylidene
(9.6 mg, 31.5 Imol) were added to a separate vial a
nd
dissolved in 3 mL of dry THF. Then the initiator/ca
talyst solution was added rapidly to
the monomer solution and the whole solution allowed
to stir for 10 min before being
precipitated into MeOH.
1
H NMR (500 MHz, CDCl
3
):
δ
(ppm) 6.29 (br t, 2H),
5.325.00
(m, 177 H), 4.404.24 (m, 3H), 3.833.69 (m, 2H), 3
.27 (s, 2H), 2.70 (br q, 2H), 1.731.39
(m, 532H), 1.251.23 (m, 1H).
M
n
(NMR)
=
13.0 kg/m
ol.
GPCMALLS:
M
n
= 12.4
kg/mol,
M
w
/M
n
=
1.11.
Representative procedure for the synthesis of a pol
y(lactide) brush copolymers (
L
B
R
-
4)
The poly(lactide) macromonomer (157.8 mg, 12.1 Jmol
) was weighed into a vial. The
catalyst (2.8 mg, 3.85 Jmol) was added to a separat
e vial. The vials were brought into the
drybox and the poly(lactide) macromonomer
was dissolved in THF (500 JL) while the
catalyst was dissolved in 1.00 mL of THF. The catal
yst solution (21 JL, 0.081 Jmol) was
injected via a microsyringe to the solution of macr
omonomers and the solution allowed to
stir for 2 hours. The reaction was moved out of the
dry box, quenched with butyl vinyl
N
O
O
O
O
O
O
O
H
n
N
O
O
OH
O
O
O
O
N N
THF, 25° C, 10 min
N
O
O
O
O
O
O
O
H
n
THF, r.t.
N
N
Mes
Mes
Ru
Ph
Cl
Cl
N
N
N
O
O
O
O
O
O
O
H
n
m
S4
ether and isolated by precipitation into MeOH. GPC
MALLS:
M
n
= 2.15 x 10
6
g/mol,
M
w
/
M
n
= 1.05.
General procedure for preparation of blends
Equal amounts (w/w) of the complementary polymers (
≈20 mg of each) were added to a
small vial and subsequently dissolved in dichlorome
thane (≈2 mL). This solution was
allowed to evaporate in the vial at room temperate
and after drying under air it was put
under high vacuum to ensure removal of the solvent.
S5
2. Supplementary Tables
Table S1.
GPC results for the macromonomers.
Sample
M
n
(10
3
g/mol)
a
M
n
(10
3
g/mol)
b
PDI
b
L
MM
1
5.9
8.16
1.18
L
MM
2
8.6
10.6
1.16
L
MM
3
11.7
14.9
1.24
L
MM
4
13.0
12.4
1.11
D
MM
1
6.6
8.54
1.17
D
MM
2
8.6
10.5
1.15
D
MM
3
10.6
10.5
1.08
D
MM
4
17.4
16
1.05
a
Measured by NMR.
b
Measured by GPC
S6
3. Supplementary Figures
Figure S1.
DSC traces of the heating cycle of the pure macrom
onomers.
100
120
140
160
180
200
220
Heat Flow
Temperature (°C]
L
MM
-1
L
MM
-2
L
MM
-3
L
MM
-4
D
MM
-1
Temperature (°C]
100
120
140
160
180
200
220
D
MM
-2
Heat Flow
D
MM
-3
D
MM
-4
S7
Figure S2.
DSC traces of the heating cycle of the pure brush
copolymers.
L
Br
-2
100
120
140
160
180
200
220
L
Br
-1
Temperature (°C]
Heat Flow
L
Br
-3
L
Br
-4
D
Br
-2
D
Br
-1
Heat Flow
D
Br
-3
100
120
140
160
180
200
220
Temperature (°C]
D
Br
-4
S8
Figure S3.
DSC traces of the heating cycle of the MM/MM blend
s (left) and the
brush/brush blends (right)
L
MM
-1+D
MM
-1
L
MM
-2+D
MM
-2
L
MM
-3+D
MM
-3
100
120
140
160
180
200
220
Temperature (°C]
Heat Flow
L
MM
-4+D
MM
-4
L
Br
-1+D
Br
-1
L
Br
-2+D
Br
-2
L
Br
-3+D
Br
-3
100
120
140
160
180
200
220
Temperature (°C]
Heat Flow
L
Br
-4+D
Br
-4
S9
Figure S4.
DSC traces of the heating cycle of the MM/brush bl
ends.
Figure S5.
DSC trace of the heating cycle of the random P
L
LA
P
D
LA
brush copolymer.
100
120
140
160
180
200
220
Temperature (°C]
L
MM
-1+D
Br
-1
Heat Flow
L
MM
-2+D
Br
-2
L
MM
-3+D
Br
-3
L
MM
-4+D
Br
-4
L
Br
-1+D
MM
-1
L
Br
-2+D
MM
-2
L
Br
-3+D
MM
-3
100
120
140
160
180
200
220
Temperature (°C]
Heat Flow
L
Br
-4+D
MM
-4
100
120
140
160
180
200
220
Temperature (°C]
Random PLLA-PDLA
brush polymer
S10
4. References
(1) Love, J. A.; Morgan, J. P.; Trnka, T. M.; Grub
bs, R. H. A Practical and Highly
Active RutheniumBased Catalyst That Effects the Cr
oss Metathesis of
Acrylonitrile.
Angew. Chem. Int. Ed.
2002
,
41
, 4035–4037.
(2) Matson, J. B.; Grubbs, R. H. Synthesis of Fluo
rine18 Functionalized
Nanoparticles for Use as in Vivo Molecular Imaging
Agents.
J. Am. Chem. Soc.
2008
,
130
, 6731–6733.