FigSupplementary information

L. Wöckel,a A. Seifert,a C. Mende,b I. Roth-Panke,b L. Kroll b and S. Spange*a

a Polymer Chemistry, Technische Universität Chemnitz, 09107 Chemnitz, Germany.

b Department of Lightweight Structures and Polymer Technology, Technische Universität Chemnitz, 09107 Chemnitz, Germany.

Fig. S 1 Liquid 1H-NMR spectra of the reaction of a) pMBC and b) mMBC with trifluoromethanesulfoic acid (TFMSA) in CDCl3 obtained at different times.

To study the reaction mechanism of the cationic polymerization of carbonates, the reaction was

monitored with liquid 1H-NMR spectroscopy. The polymerization was done at room temperature using

trifluoromethanesulfonic acid (TFMSA, tenth mol regarding carbonate). Different time intervals were

chosen to take a NMR sample from the reaction mixture. The 1H-NMR signal A (-CH2- of carbonate)

was integrated while calibrating the naphthaline standart and a decrease of carbonate conzentration

was determined. In 1H-NMR spectra methylol signals (-CH2OH) between 4.4 and 4.7 ppm appear. As

well traces of methylether bridges (-CH2OCH2-) in the region of 4.7 and 4.9 ppm can be detected. The

signals of methylenbridges (-CH2-), which can be found between 3.3 and 4.0 ppm, increases depending

on time.

All three carbonates can not be investigated with the same acid catalyst. The least reactive mMBC

shows no polymerization with trifluoroacteic acid (TFA, pKaaq ̴ 01), methanesulfonic acid (MSA,

pKaaq ̴ -21) and p-toluenesulfonic acid (pTS, pKaaq -2.81) in solution at room temperature. A strong acid

trifluoromethansulfonic acid (TFMSA, pkaaq ̴ -131) is nessecary to polymerized mMBC. Additionally,

reaction time of several days are nessecary and low conversions can be monitored within mMBC

polymerization. DFC is too reactive for polymerization with TFMSA.

Extensive investigations on molecular structure formation of anisolic resins have not been reported in

literature, yet. The assignment of NMR signals were performed according the published NMR data of

phenolic resins because anisol as a derivative of phenol can likewise polymerize to methylene bridged

anisolic resins. A overview of possible structure units and the chemical shifts in 1H- and 13C-NMR were

shown in Table S 1 2–7.

a) pMBC + TFMSA in CDCl3 naphthalin as standart b) mMBC + TFMSA in CDCl3 naphthalin as standart

8 7 6 5 4 3 2

7 d

2 d

59 min

Naphthalin H2O-C

H2-O

H

[ppm]

0 min

-CH

2-O

-CH

2-

A

-OCH3

-CH2-

HAryl

HAryl

8 7 6 5 4 3 2

2 d 16 h

Naphthalin H2O

-CH

2-O

H

360 min

59 min

1.5 min

0.3 min

[ppm]

0 min

-CH

2-O

-CH

2-

A

-OCH3

-CH2-

HAryl

HAryl

Electronic Supplementary Material (ESI) for Polymer Chemistry.This journal is © The Royal Society of Chemistry 2016

Table S 1 Molecular structure units in phenolic resin and the chemical shifts in 1H and 13C-NMR.

Structure unit Chemical shift 13C 1H-NMR

[ppm]

Structure unit Chemical shift 1H -NMR [ppm]

CArylCH3 18 CArylCH3 2.3

CArylCH2CAryl- o,o’- o,p’- p,p’-

30 35 40

CArylCH2CAryl- 3.5-4.0

CArylCH2-OH 58-65 CArylCH2-OH 4.4-4.7

CArylCH2-O-CH2CAryl 66-72 CArylCH2-O-

CH2CAryl

4.8

CArylOCH3 149-156 CArylOCH3 3.7

CArylCOOH 171 CArylCOOH 11

CArylCHO 194 CArylCHO 10

Fig. S 2 ATR-FTIR spectra of anisolic resins and polyfurfuryl alcohol resin obtained by cationic polymerization of pMBC, mMBC and DFC.

Fig. S 3 DSC measurement a) and ATR-FTIR spectra b) of polymers obtained by cationic polymerization of pMBC and mMBC with a surfactant (S) and trioxane (TO) at 90 °C.

3500 3000 2500 2000 1500 1000 500

wave number [cm1

]

DFC_60

pMBC_150

pMBC/TO_150

mMBC/TO_100

mMBC_150

(C-H)aromatic

(CH2)

(C=C)aromatic

(C=O)

a) b)

50 100 150 200 250 300

heat flow

[m

W]

temperature [°C]

exo

mMBC/1TO/S_90

pMBC/1TO/S_90

3500 3000 2500 2000 1500 1000 500

mMBC/1TO/S_90

pMBC/1TO/S_90

wave number [cm-1]

(C=O)

Fig. S 4 Liquid 1H-NMR of methoxybenzyl carbonates a) pMBC and b) mMBC compared to solid state 1H-NMR of polymers without and under addition of 1,3,5-trioxane.

Fig. S 5 Liquid 1H-NMR of difurfurylcarbonate (DFC) compared to solid state 1H-NMR of the polymer.

Low condensated polymers of pMBC and mMBC show sharp peaks in 1H solid state NMR because of

the flexibility of structure moieties. In contrast polymers crosslinked with 1,3,5-trioxane (TO) show

broad signals. The polymerized DFC exhibit as well a braod signal even without adding a cross linking

agent. The reason for this is that furfuryl moiety undergoes many side reactions where crosslinked

structures obtained. The low condensated polymers of pMBC and mMBC show sharp signals for aryl,

methoxy, methylene and water protons. A signal at 8.89.2 ppm may attributed to carboxylic acid

protons resulteded from a dehydrogenation and oxidation process of methylol species. An exact

assignment of signal is in 1H solid state NMR spectra not possible because a peak broadening and peak

shift in solid state.

a) b)

12 10 8 6 4 2 0 -2

A

-CO

OH

HAryl

mMBC

[ppm]

mMBC/TO_100

mMBC_150

H2O

-OCH3

-CH2-

B

12 10 8 6 4 2 0 -2

B

-CO

OH

pMBC

[ppm]

pMBC/TO_150

pMBC_150

HAryl

H2O

-OCH3

-CH2-

A

12 10 8 6 4 2 0 -2

-CH2-

HAryl

DFC

[ppm]

DFC_60

A

Fig. S 6 c) Liquid 13C-{1H}-NMR spectra and e) 1H-NMR spectra of organic carbonates mMBC and pMBC compared to anisolic resins polymerized with 1,3,5-trioxane at 90 °C. a), b)and d) show the molecular structures of polymers and monomers with the assignment of atoms to signals in spectra.

Fig. S 7 Pictures of polyfurfuryl alcohol resins obtained by the polymerization of DFC.

Fig. S 8 Pictures of the polyfurfuryl alcohol resins obtained by the polymerization of each one-gram DFC with 10 mol% pTS, at 60 °C under utilization of different dispersing agents. One percent by weight of a PDMS with 0.8-0.9 % silanol groups, Aerosil Ox_50 with a BET surface of 50 m2/g, Aerosil 300 with a BET surface of 300 m2/g and the polydimethylsiloxane-based surfactant (S) with the designation Dabco® DC 193 was used in each experiment. As well, a polymerization with five percent by weight of Dabco® DC 193 was performed.

b)

a)

220 200 180 160 140 120 100 80 60 40 20 0

-CH2-

-CH2- -CH3

AC

764 3

21

TO

pTS

pMBC

mMBC

5

3'6

A7

4 3

2

[ppm]

1

-CH2-

BmMBC/1TO/S_90

pMBC/1TO/S_90p,p´

o,p´

o,o´

*

c)

d)

e)

10 8 6 4 2 0

H2O

pMBC

-OCH3

HAryl

surfactant

[ppm]

mMBC

mMBC/1TO/S_90

pMBC/1TO/S_90

-CH3

pTS

Si-(CH3)3

-CH2-

A

B

-CH2-

TO

DFC/PDMS_60 DFC/50A®_60 DFC/300A®_60 DFC/1S_60DFC/5S_60

Fig. S 9 TG-MS measurements of polymers obtained by cationic polymerization of pMBC and mMBC at 100 °C. The released CO2 was detected with mass spectrometry.

Table S 2. Performed experiments under variation of amount of 1,3,5-trioxane with the molar ratios of monomer (nM) to acid catalyst (npTS) and curing agent (nTO) and the used mass ratios of the surfactant (mS). Furthermore, the endorsement of the label indicated the final polymerization temperature. The mass loss of obtained anisolic resins after extraction, curing and pyrolysis.

Sample

molar ratios [mol%]

mass ratios [wt%]

conditions T [°C] / t [h]

mass loss Δm [%]

extraction thermal treatment

nM : npTS : nTO mM : mS T1 DCM, 3d 250 °C,

Ar 800 °C, Ar

pMBC/4TO/S_100 1 : 0.1 : 1 1 : 0.01 100 / 4 89.2 22.7 50.0 mMBC/1TO/S_100 1 : 0.1 : 0.3 1 : 0.01 100 / 4 14.3 6.9 46.3 mMBC/2TO/S_100 1 : 0.1 : 0.7 1 : 0.01 100 / 4 14.1 12.5 38.5 mMBC/4TO/S_100 1 : 0.1 : 1 1 : 0.01 100 / 4 12.9 15.6 37.3 mMBC/6TO/S_100 1 : 0.1 : 1.3 1 : 0.01 100 / 4 10.1 16.6 36.3 pMBC/1TO/S_90 1 : 0.1 : 0.3 1 : 0.01 90 / 4 * 15.0 55.9 mMBC/1TO/S_90 1 : 0.1 : 0.3 1 : 0.01 90 / 4 * 17.1 55.1

* soluble in DCM

Fig. S 10 Pictures of the anisolic resins obtained by polymerization of mMBC and pMBC with 1,3,5-trioxane.

50 100 150 200 250 300

80

85

90

95

100

mMBC/4TO/S_100

mMBC/6TO/S_100

mMBC/2TO/S_100

mMBC/1TO/S_100

mass [

%]

temperature [°C]

0

1

2

3

4

5

QM

ID *

10

-9 [

A]

TG m/z = 44 (CO2)

mMBC/2TO/S_100 mMBC/4TO/S_100mMBC/1TO/S_100 mMBC/6TO/S_100pMBC/4TO/S_100

pMBC/1TO/S_90

Fig. S 11 a) DSC measurement b) and ATR-FTIR spectrum of polymers obtained by cationic polymerization of pMBC and mMBC with a surfactant (S) and different trioxane (TO) contents at 100 °C.

Fig. S 12 a) Liquid 13C-{1H}-NMR spectra and b) 1H-NMR spectra of extracts (labeled with E) obtained after extraction with dichlormethane.

The extracts of polymers were investigated by means of 1H- and 13C-{1H}-NMR spectroscopy dissolving

them in CDCl3. The 13C-{1H}-NMR spectra (Fig. S 12a) show signals for methylene (A) (29–42 ppm),

methylol (B) (58–63 ppm), methylenether groups (C) (65–75 ppm) and aromatic carbons2,3. The extract

of pMBC/4TO/S contains of o,o’-, o,p’- and p,p’-methylene linked anisolic resins which can be

attributed to signals at 29.8, 35.1 and 40.6 ppm in 13C-{1H}-NMR, respectively. The mMBC/4TO/S_100E

and mMBC/1TO/S_100E constists almost of pTS which can be seen in strong signals in the 1H- and 13C-NMR spectra (Fig. S 12a, b). In 1H-NMR the protons of methylene groups can be found between

3.5-4.0 ppm whereas methylol and methylenether groups situated between 4.4 and 4.8 ppm4. The

sample pMBC/4TO/S_100E shows no ether signals in NMR. The amount of methyleneether species in

extracts of mMBC can not be determined because the signals were overlaid with methylolprotons in 1H-NMR. Traces of carbonate monomer and surfactant found, too. Additional, in extract of polymers

produced with mMBC carbonic acid signal were found at 10.7 ppm. Signals for dichlormethan the

extraction solvent were found in 1H-NMR, too.

a) b)

25 50 75 100 125 150 175 200 225 250 275 300

mMBC/6TO/S_100

mMBC/4TO/S_100

mMBC/2TO/S_100

mMBC/1TO/S_100

heat flow

[m

W]

temperature [°C]

exo

pMBC/4TO/S_100

3500 3000 2500 2000 1500 1000 500

mMBC/6TO/S_100

mMBC/4TO/S_100

mMBC/2TO/S_100

mMBC/1TO/S_100

pMBC/4TO/S_100

wave number [cm-1]

(C=O)

a) b)

10 8 6 4 2 0

-OCH3

HAryl

A

CH2Cl

2

surfactant

[ppm]

mMBC/1TO/S_100E

mMBC/4TO/S_100E

pMBC/4TO/S_100E

-CO

OH

HAryl

-pTS

-CH3

pTS

Si-(CH3)3

-CH2-

B

200 180 160 140 120 100 80 60 40 20 0

-OC

H3

-CH

2O

CH

2-CAryl

mMBC/4TO/S_100E

CAryl

-pTS

mMBC/1TO/S_100E

[ppm]

pMBC/4TO/S_100E

3'

6

A

7

432

1 -CH2-

B

-CH3

pTS

p,p´

o,p´

o,o´

Fig. S 13 a) The mechanism for levulinic acid formation from the reaction of furfuryl alcohol with acids8. b) Liquid 13C-{1H}-NMR spectra and b) 1H-NMR spectra of extracts (labeled with E) obtained after extraction of DFC/S_60 with dichlormethane.

The polymer DFC/S_60 shows a extractable content of 24.6 %. The liquid 13C-{1H}-NMR spectra (Fig. S

13b) and 1H-NMR spectra (Fig. S 13c) of the extract exhibit mainly signals of pTS and levulinic acid.

Leviulinic acid is a side product of the cationic polymerization of furfuryl alcohol due to a hydrolytic

furan ring opening8. The mechanism is shown in Fig. S 13a.

Fig. S 14 SEM images of the anisolic resins obtained by cationic polymerization mMBC at 100 °C with 1,3,5-trioxane. SEM images of the annealed (A) anisolic resins at 250 °C. The inset shows the picture of the polymer foam.

10 8 6 4 2 0

a

c

CH2Cl

2

A

[ppm]

DFC/S_60E

HAryl

-pTS

-CH3

pTS

-CH2-

B

d

200 150 100 50 0

b

acetone-d6 a

CAryl

-pTS

e

c

acetone-d6

[ppm]

DFC/S_60E

-CH3

pTS

-CH2-

d

a)

b) c)

mMBC/2TO/S_100 mMBC/2TO/S_100-A

mMBC/6TO/S_100-AmMBC/6TO/S_100

a) b)

c) d)

Fig. S 15 SEM images of the anisolic resins obtained by cationic polymerization mMBC at 100 °C with 1,3,5-trioxane. SEM images of the annealed (A) anisolic resins at 250 °C. The inset shows the picture of the polymer foam.

Fig. S 16 The cumulative volume and pore size distribution of DFC/S_60-C and mMBC/1TO/S_90-A obtained by mercury porosimetry measurement.

1 D. R. MacFarlane, J. M. Pringle, K. M. Johansson, S. A. Forsyth and M. Forsyth, Chem. Commun., 2006, 1905.

2 X. Zhang, A. C. Potter and D. H. Solomon, Polymer, 1998, 39, 399–404. 3 G. E. Maciel, I. S. Chuang and L. Gollob, Macromolecules, 1984, 17, 1081–1087. 4 P. W. Kopf and E. R. Wagner, J. Polym. Sci. Polym. Chem. Ed., 1973, 11, 939–960. 5 I. S. Chuang and G. E. Maciel, Macromolecules, 1991, 24, 1025–1032. 6 I. S. Chuang and G. E. Maciel, Annu. Rep. NMR Spectrosc., 1994, 29, 169–286. 7 A. Gardziella, L. A. Pilato and A. Knop, Phenolic resins: Chemistry, Application, Standardization,

Safety and Ecology, Springer, 2nd Completely Revised Edition., 2000. 8 A. M. Nathanael Guigo, Polym. Degrad. Stab., 2009, 94, 908–913.

mMBC/1TO/S_100 mMBC/1TO/S_100-A

a) b)

mMBC/4TO/S_100-AmMBC/4TO/S_100

c) d)

0.010.11101001000

0.0

1.0

2.0

3.0

4.0

5.0

cum. volume

cum

ula

tive p

ore

volu

me [cm

3/g

]

pore diameter [m]

0.0

0.1

0.2

0.3

0.4

0.5

0.6

mMBC/1TO/S_90A-C

rel. pore volume

rela

tive p

ore

volu

me [%

]

DFC/S_60-C