Inducing hardening and healability in poly(ethylene-co-acrylic acid) via blending

with complementary low molecular weight additives

Benjamin C. Bakera; I. Germanb; Gary C. Stevensb; Howard M. Colquhouna; and Wayne Hayes a*

a Department of Chemistry, University of Reading, Whiteknights, Reading, RG6 6AD, UK. Email:

w.c.hayes@reading.ac.uk, Telephone: +44 118 378 6491, Fax: +44 118 378 6331

b Gnosys Global Ltd., 17-18 Frederick Sanger Road, The Surrey Research Park, Guildford, Surrey, GU2 7YD,

UK

Supplementary Information

Contents Page

Scheme S1 Synthetic route to compounds 3-5. S1

Figures S1-S9 1H and 13C NMR spectra of 3-6 in DMSO-d6 or CD3OD plus S2

IR spectra.

Figures S10-S12 Gelator 3: rheology and UV-vis absorption characteristics. S9

Figure S13 DSC data for pEAA15/1 (10% wt). S11

Figures S14-S20 Stress-strain curves for pEEA15 and additives 1-7 (1/5% wt). S11

Figures S21-S24 DSC thermograms for pEAA15/1-3 (0, 1 and 5% wt). S15

Figures S25-S28 Relaxation DSC scans of pEEA15/1-3 (0, 1 and 5% wt). S16

Tables S1-S3 Tensile properties of pEAA15 and pEEA15/1-3 after healing. S18

Figures S29-S39 Stress-strain curves for pEAA15 and pEEA15/1-3 after healing. S19

Figures S40-S41 DSC thermograms of pEAA5 and pEAA20 with 1 and 3. S24

Figures S42-S45 Stress strain curves for pEAA20 with 1 and 3. S25

Electronic Supplementary Material (ESI) for RSC Advances.This journal is © The Royal Society of Chemistry 2018

S1

Scheme S1; Generic synthesis of compounds 3-5 (3: R1 = H, R2 = NO2. 4: R1 = NO2, R2 = H. 5: R1

= H, R2 = H).

S2

Figure S1; 1H and 13C NMR spectra of 3 in DMSO-d6

S3

Figure S2; 1H NMR spectrum of 3 in CD3OD

Figure S3; IR spectra of 3

40

50

60

70

80

90

100

800130018002300280033003800

Ab

sorb

ance

(%

)

Wavenumber (cm-1)

S4

Figure S4; 1H and 13C NMR spectra of 4 in DMSO-d6

S5

Figure S5; IR spectra of 4

75

80

85

90

95

100

800130018002300280033003800

Ab

sorb

ance

%

Wavenumber cm-1

S6

Figure S6; 1H and 13C NMR spectra of 5 in DMSO-d6

S7

Figure S7; IR spectra of 5

84

86

88

90

92

94

96

98

100

102

800130018002300280033003800

Ab

sorb

ance

(%

)

Wavenumber (cm-1)

S8

Figure S8; 1H and 13C NMR spectra of 6 in DMSO-d6

S9

Figure S9; IR spectra of 6

Figure S10; Hydrogelator 3, CGC 2.7 mM (0.1%wt)

60

65

70

75

80

85

90

95

100

105

110

800130018002300280033003800

Ab

sorb

ance

(%

)

Wavenumber (cm-1)

S10

Figure S11; Rheology of aqueous gel of hydrogelator 3 (20 mM).

Figure S12; UV/vis absorption spectra of stirred solution of aqueous methylene blue (250 mL, 8 mg

L-1) after addition of hydrogelator 3 (1 mL, 80 mM).

5 50 500

1

10

100

1000

10000

Shear rate (rad/s)

Mo

du

lus

(KP

a)

G'

G"

500 550 600 650 700

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

Wavenlength (nm)

Ab

sorb

ance

0 min

1 hour

24 hour

48 hour

S11

Figure S13; DSC heating (lower) and cooling (upper) curves for pEAA15 /1 (10% wt) showing

phase separation of polymer and dicarboxylic acid 1 (represented by the melting transition at 120

C).

Figure S14; Stress strain curves (average of five samples) for; pEEA15 (black), pEEA15/1 (1% wt.)

(red) and pEEA15/1 (5% wt.) (blue).

0

0.5

1

1.5

2

2.5

3

3.5

4

0 0.02 0.04 0.06 0.08 0.1 0.12

Stre

ss (

MP

a)

Strain

S12

Figure S15; Stress strain curves (average of five samples) for pEEA15/2 (1% wt) (red) and

pEEA15/2 (5% wt) (blue).

Figure S16; Stress strain curves (average of five samples) for pEEA15/3 (1% wt) (red) and

pEEA15/3 (5% wt) (blue).

0

0.5

1

1.5

2

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

Stre

ss (

MP

a)

Strain

0

0.5

1

1.5

2

2.5

3

0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2

Stre

ss (

MP

a)

Strain

S13

Figure S17; Stress strain curves (average of five samples) for pEAA15 and 4 at 1% (red) and 5%

(blue) wt.

Figure S18; Stress strain curves (average of five samples) for pEAA15 and 5 at 1% (red) and 5%

(blue) wt.

0

0.5

1

1.5

2

2.5

0 0.05 0.1 0.15 0.2

Stre

ss (

MP

a)

Strain

0

0.5

1

1.5

2

2.5

0 0.05 0.1 0.15 0.2

Stre

ss (

MP

a)

Strain

S14

Figure S19; Stress strain curves (average of five samples) for pEAA15 and 6 at 1% (red) and 5%

(blue) wt.

Figure S20; Stress strain curve (average of five samples) for pEAA15 and 7 at 1% wt.

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

0 0.05 0.1 0.15 0.2 0.25

Stre

ss (

MP

a)

Strain

0

0.5

1

1.5

2

2.5

0 0.05 0.1 0.15 0.2

Stre

ss (

MP

a)

Strain

S15

Figure S21; DSC heating scan (below) and subsequent cooling scan (above) of pEEA15.

Figure S22; DSC heating/cooling scans of pEEA15/1 at 1% (red) and 5% weight (blue).

Figure S23; DSC heating/cooling scans of pEEA15/2 at 1% (red) and 5% weight (blue).

S16

Figure S24; DSC heating/cooling scans of pEEA15/3 at 1% (red) and 5% weight (blue).

Figure S25; Relaxation DSC scan of pEEA15 (48 hours after scan shown in Figure S19).

Figure S26; Relaxation DSC scans of pEEA15 /1 at 1% (red) and 5% wt. (blue) (taken 48 hours

after scan shown in Figure S20).

S17

Figure S27; Relaxation DSC scan of pEEA15/2 at 1% (red) and 5% wt. (blue) (taken 48 hours after

scan shown in Figure S21).

Figure S28; Relaxation DSC scan of pEEA15/3 at 1% (red) and 5% wt. (blue) (taken 48 hours after

scan shown in Figure S22).

S18

Table S1; Tensile properties after heating fractured films at 50 °C for 8 hours.

Table S2; Tensile properties after heating fractured films at 60 °C for 2 hours.

Film

System

% wt

additive

Tensile

Strength

(MPa)

Fracture

Stress

(MPa)

Uniform

Strain

(%)

Strain to

Fracture

(%)

Energy

absorbed

(MPa)

Young’s

Modulus

(MPa)

pEEA15 0.39 0.37 1.67 1.74 0.008 14.22

pEEA15/1 5 - - - - - -

pEEA15/2 1 0.72 0.63 4.43 5.26 0.03 17.97

pEEA15/3 5 1.12 1.12 2.29 2.37 0.021 28.53

Table S3; Tensile properties after pressing (0.98 MPa) fractured films for 8 hours.

Film

System

% wt

additive

Tensile

Strength

(MPa)

Fracture

Stress

(MPa)

Uniform

Strain

(%)

Strain to

Fracture

(%)

Energy

absorbed

(MPa)

Young’s

Modulus

(MPa)

pEEA15 1.00 0.84 6.15 7.38 0.06 26.31

pEEA15/1 5 1.35 0.93 6.75 9.68 0.10 21.83

pEEA15/2 1 0.20 0.15 1.07 1.23 0.007 18.60

pEEA15/3 5 1.95 0.96 5.62 7.48 0.14 41.43

Film

System

% wt

additive

Tensile

Strength

(MPa)

Fracture

Stress

(MPa)

Uniform

Strain

(%)

Strain to

Fracture

(%)

Energy

absorbed

(MPa)

Young’s

Modulus

(MPa)

pEEA15 0.12 0.12 1.56 1.60 0.002 5.68

pEEA15/1 5 0.09 0.09 0.53 0.56 0.001 13.12

pEEA15/2 1 0.57 0.57 1.50 1.58 0.013 23.23

pEEA15/3 5 0.88 0.88 2.30 2.42 0.013 18.61

S19

Figure S29; Stress-strain curve (average of five samples) for pEAA15 after healing at 60 ˚C (2

hours)

Figure S30; Stress-strain curve (average of five samples) for pEAA15/2 (1% wt) after healing at 60

˚C (2 hours)

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

0.5

0 0.005 0.01 0.015 0.02

Stre

ss (

MP

a)

Strain

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

0 0.01 0.02 0.03 0.04 0.05 0.06

Stre

ss (

MP

a)

Strain

S20

Figure S31; Stress-strain curve (average of five samples) for pEAA15/3 (5% wt) after healing at 60

˚C (2 hours)

Figure S32; Stress-strain curve (average of five samples) for pEAA15 after healing at 50 ˚C (8

hours).

0

0.2

0.4

0.6

0.8

1

1.2

1.4

0 0.005 0.01 0.015 0.02 0.025

Stre

ss (

MP

a)

Strain

0.00

0.02

0.04

0.06

0.08

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0.12

0.14

0 0.005 0.01 0.015 0.02

Stre

ss (

MP

a)

Strain

S21

Figure S33; Stress-strain curve for pEAA15/1 (5% wt) after healing at 50 ˚C (8 hours)

Figure S34; Stress-strain curve (average of five samples) for pEAA15/3 (5% wt) after healing at 50

˚C (8 hours)

0

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

0 0.001 0.002 0.003 0.004 0.005 0.006

Stre

ss (

MP

a)

Strain

0

0.2

0.4

0.6

0.8

1

1.2

0 0.005 0.01 0.015 0.02 0.025 0.03

Stre

ss (

MP

a)

Strain

S22

Figure S35; Stress-strain curve (average of five samples) for pEAA15/2 (1% wt) after healing at 50

˚C (8 hours)

Figure S36; Stress-strain curve (average of five samples) for pEAA15 after healing under pressure

(0.98 MPa, 8 hours)

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0 0.005 0.01 0.015 0.02

Stre

ss M

Pa

Stress

0

0.2

0.4

0.6

0.8

1

1.2

1.4

0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08

Stre

ss (

MP

a)

Strain

S23

Figure S37; Stress-strain curve (average of five samples) for pEAA15/1 (5% wt) after healing under

pressure (0.98 MPa, 8 hours)

Figure S38; Stress-strain curve (average of five samples) for pEAA15/2 (1% wt) after healing under

pressure (0.98 MPa, 8 hours)

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

0 0.02 0.04 0.06 0.08 0.1 0.12

Stre

ss (

MP

a)

Strain

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0 0.002 0.004 0.006 0.008 0.01 0.012 0.014

Stre

ss (

MP

a)

Strain

S24

Figure S39; Stress-strain curve (average of five samples) for pEAA15/3 (5% wt) after healing under

pressure (0.98 MPa, 8 hours)

Figure S40; DSC thermograms for pEAA20 (black) and pEAA20/1 (blue) and 3 (red) each at 10%

wt. The three lower traces are the heating scans and the three upper traces are the cooling scans.

0

0.5

1

1.5

2

2.5

0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08

Stre

ss (

MP

a)

Strain

S25

Figure S41; DSC thermograms for pEAA5 (black) and pEAA5/1 (red) at 2% wt.

Figure S42; Stress-strain curve (average of five samples) of pEAA20.

0

1

2

3

4

5

6

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

Stre

ss (

MP

a)

Strain

131 °C

S26

Figure S43; Stress-strain curve of pEAA20/1 (10% wt).

Figure S44; Stress-strain curve (average of five samples) of pEAA20/3 (10% wt).

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

0 0.2 0.4 0.6 0.8 1 1.2 1.4

Stre

ss (

MP

a)

Strain

0

1

2

3

4

5

6

7

8

9

10

0 0.2 0.4 0.6 0.8 1 1.2

Stre

ss (

MP

a)

Strain

S27

Figure S45; Stress-strain curve (average of five samples) of pEAA20/3 (10% wt) after healing under

pressure (0.98 MPa, 8 hours).

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35

Stre

ss (

MP

a)

Strain