Facile Preparation of Lignin-Based Underwater Adhesives with

Subscriber access provided by TULANE UNIVERSITY

Article

Facile preparation of lignin-based underwater adhesives with improved performances Congying Wei, Xiangwei Zhu, Haiyan Peng, Jianjun Chen, Fang Zhang, and Qiang Zhao ACS Sustainable Chem. Eng., Just Accepted Manuscript • DOI: 10.1021/ acssuschemeng.8b06731 • Publication Date (Web): 04 Feb 2019 Downloaded from http://pubs.acs.org on February 4, 2019

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 18 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ACS Sustainable Chemistry & Engineering

1

Facile preparation of lignin-based underwater adhesives with

2

improved performances

3

Congying Wei,‡ Xiangwei Zhu,‡ Haiyan Peng, Jianjun Chen, Fang Zhang, and Qiang Zhao*

4

Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education,

5

School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology,

6

1037 Luoyu Road, Wuhan 430074 China. E-mail: [email protected]

7

KEYWORDS: Lignosulfonate, Value-added bioprocessing, Underwater adhesive, Coacervate,

8

Self-curing

9

ABSTRACT: Bioinspired wet adhesives have demonstrated versatile applicability in humid

10

conditions, but the attainment of catecholic protein mimics comprises multi-step synthesis and use

11

of complex chemical components. Advanced wet adhesives derived from inexpensive bio-

12

resources and green processing are highly expected. We report a straightforward means to

13

underwater-implemented adhesives from aqueous mixing of lignosulfonate (LS) and

14

polyamidoamine-epichlorohydrin (PAE-Cl) solution. The formation of fluidic LS-PAE complex

15

was driven by a delicate balance between electrostatic attraction and hydrophilic stabilization. The

16

obtained adhesive highlights instant wet adhesion on diverse submerged surfaces and spontaneous

17

curing in water. More importantly, it demonstrates robust and stable bonding strength over the

18

alkali, salty, high-temperature and long-time soaking conditions. This work advanced the

19

development of lignin into functional wet adhesives through a green and sustainable approach.

20

ACS Paragon Plus Environment

1

ACS Sustainable Chemistry & Engineering 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 2 of 18

1

INTRODUCTION

2

Wet adhesion is indispensable to various applications spanning from surgery closure,

3

underwater fixing, to aqueous coating and surface engineering etc.1–3 Conventional

4

adhesives lack sufficient hydrophilicity and frequently fail to submerged hydrophilic

5

substrates because of reduced interfacial bonding in the presence of surface water

6

molecules.4,5 Marine mussels and sandcastle worms are known for their exceptional ability

7

of underwater adhesion through the synergy of catecholic protein sequence and controlled

8

coacervate.6 Oppositely charged proteins were mixed to form catechol-containing

9

coacervate, a water immiscible fluid which spreads over submerged substrates and allows

10

for wet adhesion through the combination of supramolecular interfacial interactions and

11

self-oxidative crosslinking.7,8 Despite catechol’s enabling roles, the synthesis of catechol-

12

containing polymers is hard to scale and involves complicated functionalization, and/or

13

protection treatments because catechol groups are prone to self-oxidation.9–11 Moreover,

14

sequence control of catechol groups in synthetic polymers remains unresolved challenges

15

so far.12 To improve the sustainability of facile processing to wet adhesives, a catechol-free

16

coacervation strategy compatible with low-cost resource biopolymers is highly demanded.

17

Lignosulfonate (LS) is a major byproduct from the pulping residues of lignocellulose biomass,

18

accounting for 90% of the total market of commercial lignins.13,14 Regardless of the large

19

availability (1.8 million tons annual production worldwide), LS valorization is still in the early

20

development stage, representing only 2% of the lignin production from industries.15 The vast

21

majority of LS is inefficiently utilized as industrial additives or even burnt as a low-value fuel,

22

imposing resources and environmental constrains.16,17 Value-added processing of LS, thus,

23

represents as an important task in advancing its sustainable utilization.18 Concomitantly, LS-based

24

composites have been developed by blending with various polymeric formulations.14 However,

25

owing to the abundant sulfonate groups, LS features high polarity and exhibits poor miscibility

26

with many other polymers when fabricating the moldable and functional materials.17 One effective

27

solution is to deprotonate or desulfonate LS to reduce their polarity.19,20 Nevertheless, rational

28

utilization of negatively charged sulfonate groups of LS has been less realized.

29

Alternatively, liquid-liquid phase separation driven by electrostatic complexation between

30

oppositely charged polyelectrolytes is a major route to obtain the bio-inspired coacervate

31

adhesive.21 From this perspective, LS represents a potential candidate to complex coacervate once


2

Page 3 of 18 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


1

paired with appropriate cationic polyelectrolytes. Given the easy availability and bio-compatibility

2

of LS resources, the obtained coacervate could serve as an economical and green platform for

3

advanced wet adhesives. Despite these potential benefits, however, randomly blending of LS with

4

poly-cations (e.g., poly(N-methylaniline) or poly(allylamine)) can hardly produce any complex

5

coacervate; instead, solid precipitations or homogeneous solutions were observed.21,22 The

6

formation of complex coacervates requires exquisite maneuver of polyelectrolyte charge

7

properties and optimization of the solution-mixing conditions.23 For this reason, LS-based

8

complex coacervates remained unreported.

9

In this study, we screened and selected polyamidoamine-epichlorohydrin (PAE-Cl), an

10

economic commercial additive applied in the cellulose and fiber industry,24 as the cationic

11

candidate, and induced its electrostatic complexation with LS to develop a fluidic and underwater

12

implemented wet adhesive. Both ingredients boost highly water solubility, which facilitates their

13

green processing using water as the solvent. The complexation was confirmed by Fourier-

14

transform infrared (FT-IR) spectroscopy and Elemental analysis. Contact adhesion and curing

15

behavior of obtained adhesives were characterized by underwater pull-off test, rheological test and

16

1

17

pH, salt, temperature and long-time soaking.

H NMR. Robust wet adhesion was achieved on various substrates and found to be stable against

18 19

EXPERIMENTAL SECTION

20

Materials. Polyamidoamine-epichlorohydrin (PAE-Cl) was kindly donated by Golden

21

Huasheng Paper ltd., Suzhou, China. The solid content and charge density of the PAE-Cl solution

22

(pH 4.2) were measured to be 12.5 wt % and 2.5 meq/g. Sodium lignosulfonate (molecular weight

23

~ 52 KDa, charge density 1.8 meq/g), Poly(allylamine hydrochloride) (average Mw ~ 50 Kda),

24

Poly(ethylene imine) (average molecular weight ~ 70 KDa) and Poly(diallyldimethylammonium

25

chloride) (molecular weight 200-350 KDa) were purchased from Sigma-Aldrich, St. Louis, MO,

26

USA. Chitosan quaternary ammonium salt was provided by Zhejiang golden-shell pharmaceutical

27

co., ltd, Yuhuan, All chemicals were used as received. Deionized water (conductivity: 0.6 µS/cm)

28

was used in this work.

29

Preparation of LS-PAE adhesive. Lignosulfonate (LS) solution was prepared at 100 mg/mL

30

and added into equal volume of PAE-Cl solution (125 mg/mL) dropwise under magnetic stirring


3


Page 4 of 18

1

(400 rpm). Turbidity was observed once the LS solution was added. After 20-minute settling,

2

fluidic wet adhesive was obtained at the bottom of the glass beaker and applied directly.

3

Characterizations. Fourier-transform infrared spectroscopy (FT-IR) was carried out on a

4

Bruker Vertex 80V FT-IR spectrometer with 32 scans at a resolution of 4 cm–1 by using KBr pellet.

5

Elemental analysis (C, H, N, S) was performed on a Flash EA1112 from ThermoQuest Italia S.P.A.

6

Nuclear Magnetic Resonance (1H NMR) spectra of PAE were recorded on a Bruker Avance 400

7

spectrometer at room temperature. Turbidity of LS-PAE complex at different salt concentration (0

8

M to 1.0 M) was measured at 600 nm by UV–vis spectrophotometry (Shimadzu UV-1900, Japan).

9

The relative turbidity is defined as 100 − 100 × 10−A (600). Rheological measurements were carried

10

out on an Anto Paar MCR 302 rheometer at 25 °C. Two parallel stainless steel plates (diameter:

11

25 mm, gap: 0.5 mm) were used to sandwich the sample during characterization. Oscillatory strain

12

sweep was run from 0.1 to 1000, and 1% as the amplitude was the optimized condition within the

13

linear viscoelastic regime. Oscillatory frequency sweep data were collected in the range from 0.1

14

to 100 rad/s. All measurements were repeated for at least three times.

15

Adhesion tests. The pull-off adhesion of LS-PAE was tested according to the modified version

16

of the ASTM standardized method.25 Typically, two substrate panels were pre-submerged in water,

17

and adhesive (0.25 g) was sandwiched between the two panels in-situ in water, with a lap shear

18

joint of 1.0 cm ×1.0 cm. External pressure (40 KPa, 0.4 N) was applied to the bonding area for 5

19

seconds once the adhesive was underwater dispensed, and a small portion of coacervate (~ 0.028

20

g, 11.2% to the applied coacervate 0.25 g) was squeezed out during this process. Afterwards, the

21

coacervate adhesive was spontaneously cured underwater with no pressure applied. The adhesion

22

measurement was performed in a water-filled chamber on a Suns Tech UTM2103 universal testing

23

machine with a 1000 N loading cell at a strain rate of 20 mm/min. Adhesion strength was obtained

24

from the maximum force at joint failure divided by the overlap area. Each test was replicated at

25

least 5 times and averaged.

26

Instant underwater adhesion of LS-PAE was tested on different substrates, including glass,

27

aluminum, stainless steel, ceramics, and poly tetra fluoroethylene (PTFE). The adhesive was

28

uniformly dispensed on a submerged glass surface (1.0 cm × 1.0 cm), which was pre-fixed to a

29

stainless steel baseboard by commercially available Glue (Gorilla Glue). Then, the second glass

30

panel (1.0 cm × 1.0 cm) was overlapped with a stabilized steel dolly. Immediately, the dolly was

31

hooked to the sensor of a Universal Testing Machine for pull-off tests.


4

Page 5 of 18 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


1

For the adhesion stability, the adhesive was underwater implemented in between two glass

2

substrates and cured in the acid condition (0.2 M PBS buffer at pH 3 and 5), DI water, alkali

3

conditions (0.2 M PBS buffer at pH 8-11), salty solutions (0.2 M, 0.5 M, 0.8 M and 1.0 M NaCl)

4

and elevated temperatures (50 °C, 80 °C and 100 °C) respectively. The adhesion strength was

5

measured after 2-day conditioning. Soaking stability of LS-PAE adhesive was measured by

6

consecutively recording the wet adhesion strength from 0 to 30 days.

7 8

RESULTS AND DISCUSSION

9

Preparation of Lignosulfonate-PAE complex (LS-PAE) adhesive. The LS-PAE wet adhesive

10

was prepared through the solution mixing of lignosulfonate (LS) aqueous solution (1.5 mL, 100

11

mg/mL) with PAE-Cl aqueous solution (1.5 mL, 125 mg/mL). Liquid-liquid phase separation, i.e.,

12

coacervation, occurred immediately, which after settling, yield a highly viscous but fluidic

13

coacervate phase with brown color (Figure 1a,b and viscosity test in Figure S1). Electrostatic

14

complexation between the sulfonate and azetinidium group is responsible for the chain

15

aggregations. Meanwhile, the counter-balance effect by PAE’s intrinsic hydrophilicity (from the

16

hydroxyls and amide linkage) reconciles colloidal stability (Figure 1c), and with their delicate

17

interplay, fluidic adhesive formed instead of uncontrolled precipitates.26

18


5


Page 6 of 18

1

Figure 1. (a) Chemical structures of PAE-Cl and LS. (b) LS-PAE coacervate prepared by solution

2

mixing PAE-Cl (1.5 mL, 125 mg/mL) and LS (1.5 mL, 100 mg/mL) aqueous solution. (c)

3

Represented functional groups involved in the coacervate formation. (d) Complexations of LS with

4

four types of reference polyelectrolytes: i) QCS: chitosan quaternary ammonium salt, ii) PDDA:

5

poly(diallyldimethylammonium chloride), iii) PEI: poly(ethylene imine) and iv) and PAH:

6

poly(allylamine hydrochloride). The LS solution (1.5 mL, 100 mg/mL) was mixed with equal

7

volume of cationic polyelectrolyte solutions (125 mg/mL) respectively. Glass vials were inverted

8

after 20-min conditioning.

9

For comparison, LS solution was mixed with other cationic polyelectrolytes (QCS, PDDA, PEI,

10

PAH, Figure 1d) to observe their complexation behaviors. For QCS and PDDA comprising stiff

11

pyran rings or hydrophobic alkyls, precipitation occurred when mixing with anionic LS, indicative

12

of strong complexation. On the other hand, the weak cationic polyelectrolytes, PEI and PAH,

13

manifested no detectable phase separation when mixed with LS solution, denoting their

14

insufficient complexation. Taking the flexible polymeric structures and cationic charge density

15

into consideration, PAE-Cl represented an ideal candidate to prepare LS-based coacervate

16

adhesive through aqueous mixing.

17

Rheological measurements show that LS-PAE complex exhibit fluidic nature as its G’’ value is

18

relatively higher than G’ under full range of oscillatory stain sweep (Figure 2a). Characteristic

19

peaks for both the LS (1510 cm−1 for benzene rings and 1035 cm−1 for sulfonate) and PAE (1635

20

cm-1 for amide linkage) were found from the FT-IR spectra of LS-PAE complex coacervate (Figure

21

2b). From their thermal degradation curves, a new peak appeared at 340 °C for LS-PAE (Figure

22

S2). Moreover, the nitrogen element content in LS-PAE coacervate is 6.6 wt%, on basis of which

23

the LS content in LS-PAE is calculated to be 61.8 wt% (Elemental anylisis, Table S1). All these

24

results indicate that coacervate was obtained as a result of the complexation between PAE and LS.


6

Page 7 of 18 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


1 2

Figure 2. (a) Storage (G’) and loss (G’’) moduli versus strain of LS-PAE coacervate (Figure 1b),

3

(b) FT-IR spectra of the lyophilized PAE-Cl, LS, and LS-PAE coacervate. Characteristic peaks of

4

each component were labeled.

5

Underwater adhesion performance. The instant contact wet adhesion of LS-PAE was measured

6

by underwater pull-off test (Figure S3) and showed substrate-dependent (Figure 3a) performances,

7

i.e., 122.3 ±14.3 KPa for glass, 104.8 ±17.5 KPa for aluminum, 80.1 ±8.6 KPa for stainless steel,

8

42.6 ±9.4 KPa for ceramics, and 14.2 ±3.7 KPa for polytetra fluoroethylene (PTFE), respectively.

9

After 2-day conditioning, the adhesion strength increased drastically to ~ 400 KPa for glass,

10

aluminum and stainless steel, and ~ 300 KPa for ceramics. Optical examinations shown that

11

cohesion failure occurred for glass, aluminum, stainless steel and ceramics substrates, while

12

interfacial glue exfoliation was dominant for PTFE (Figure S4). LS-PAE experienced spontaneous

13

curing in the water (mechanism discussed at Figure 5), and thus the increased adhesion strength

14

was reasonably attributed to the reinforced cohesion of LS-PAE coacervate. However, on PTFE

15

substrate, the adhesion strength of LS-PAE only experienced a minor increase to 50.6 ±16.2 KPa,

16

suggesting the limited interfacial interaction of LS-PAE with hydrophobic PTFE surface. A

17

demonstrative example was shown whereby two pieces of underwater bonded steel sheet was able

18

to lift a 2.0 kg weight (Figure 3c).

19

Here the catechol-free LS-PAE features instant wet adhesion comparable to state-of-the-art

20

performances,27,28 and more importantly, self-curing ability rarely observed for catechol-free

21

coacervates. Catechol-containing polymers are widely exploited to develop robust underwater

22

adhesives, and organic solvents are needed for materials processing and/or the polymer synthesis

23

that normally involves multiple complicated steps to reconcile the sensitive catechol groups for


7


Page 8 of 18

1

improved adhesion.29 In this work, not only the raw materials for LS-PAE coacervate (61.8 wt%

2

LS, Table S1) are from economic resources and renewable lignin byproducts, but also the

3

processing is straightforward and waterborne. Thus, the environment constraints have been largely

4

alleviated by this sustainable strategy.

5 6

Figure 3. (a) Adhesion strength of LS-PAE adhesive on different substrates. Note: pull-off tests

7

were conducted immediately (instant adhesion) after the underwater implementation of LS-PAE

8

adhesive, or after 48h-conditioning in DI water (cured adhesion). Al: aluminum, SS: stainless steel,

9

PTFE: poly(tetra fluoroethylene). The bonding strength development with the curing time was

10

plotted in Figure S5. (b) Cartoon illustrating the underwater implementation of LS-PAE adhesives.

11

(c) A demonstration of underwater implemented LS-PAE adhesive (48 h conditioning) bearing 2

12

kg load.

13

The underwater curing effect of LS-PAE was confirmed from rheological (Figure 4) and 1H

14

NMR (Figure 5) data. Consistent with strain sweep (Figure 2a), frequency sweep of pristine LS-

15

PAE exhibited relatively higher G’’ to G’, indicative of its liquid-like feature. After conditioning,

16

the G’ value experienced significant increase and exceeded G’’, suggesting the curing effect to the

17

adhesive.


8

Page 9 of 18 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


1 2

Figure 4. Storage (G’) and loss (G”) moduli versus frequency of LS-PAE adhesive before (pristine)

3

and after 2 days curing in the water.

4

From 1H NMR, little changes were observed when PAE was conditioned at pH 3 (Figure 5a,

5

PAE-3). In contrast, two distinct peaks appear at 3.23 ppm (g’) and 2.62 ppm (h’) when PAE was

6

cured at pH 7 and pH 9, respectively. These two peaks denote the ring-open crosslinking reaction

7

between the azetinidium and amine groups (Figure 5b).30,31 As such, the self-curing behavior of

8

LS-PAE adhesive was attributed to its reactive azetinidium groups from PAE resin, whose self-

9

crosslinking reaction was inhibited in the acid, and trigged in the neutral and/or base

10

conditions.30,32 On the other hand, LS plays structural role for the reinforced adhesion through the

11

electrostatic complexation with PAE.33 A control coacervate adhesive was made by mixing PAE

12

with sodium dodecyl sulfonate, and show much reduced wet adhesion compared to LS-PAE

13

coacervate (Figure S6) due to the lack of network complexation. It is noteworthy that catechol

14

groups are efficient in improving both the interfacial adhesion and cohesion strength through

15

multiple supramolecular interactions (e.g., hydrogen bonding, metal chelation, cation-π, etc) and

16

self-oxidative cross-linking, respectively.2,34,35 Here the LS-PAE system in this work provides a

17

materials platform simultaneously integrating high interfacial bonding, self-curing properties,

18

inexpensive resources and green processing in one single system. Yet the LS-PAE coacervate is

19

catechol-free, and highlights waterborne preparation that is straightforward, sustainable, and labor-

20

efficient.


9


Page 10 of 18

1 2

Figure 5. (a) 1H NMR spectra of PAE solutions conditioned at pH 3, 7, 9 (named as PAE-3, -7,

3

and -9) for 2 days, and the corresponding structural changes. (b) NMR spectra of pristine PAE was

4

indicated as the reference.31,33

5

The performance of wet adhesive is frequently challenged by complicated practical

6

conditions.8,26,36,37 Adhesion stability of LS-PAE against pH, salt concentration, temperature, and

7

soaking time was studied. LS-PAE adhesive exhibits moderate adhesion strength in acidic

8

condition (pH 3 ~ 6) and a much higher performance in near neutral and base conditions (Figure

9

6a, pH 6 ~ 11), in stark contrast to the literature results suffering from reduced adhesion in the

10

alkali conditions.35,38–40 The stable adhesion in base condition is reasonably due to the self-curing

11

properties of PAE (Figure 5). For better comparison, wet adhesion strength of LS-PAE was

12

benchmarked against representative commercial glues in both water and pH 9 PBS buffer (Figure

13

6b). The PVA and Starch glue were unable to survive even in DI water. Polyurethane-based

14

commercial adhesive displayed underwater adhesion of 360.2 ± 52.6 KPa for Gorrila glue and

15

400.6 ± 60.5 KPa for 3M Marine. However, both of them are not alkali-resistant, as the wet

16

adhesion strength decreased massively when the pH of bulk solution went to 9. Collectively, the

17

LS-PAE adhesive represented a suited candidate for alkali-demanding conditions.4,27,35,39


10

Page 11 of 18 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


1 2

Figure 6. (a) Adhesion strength of LS-PAE adhesive at different pH. (b) Underwater adhesion

3

strength (48 h conditioning) of LS-PAE adhesive compared to commercial glues in DI water and

4

pH 9 condition. Glass was bonded as the substrate.

5

In addition, the adhesion strength of LS-PAE was maintained ~ 380 KPa when the NaCl

6

concentration of bulk solution was increased to 0.8 M (~1.5 times of common seawater salinity),

7

and experienced a 10 % decrease with increasing salt concentration to 1.0 M (Figure 7a). Both LS

8

and PAE-Cl are strong polyelectrolytes, and their inter-polyelectrolyte complexation was less

9

affected by salts,41 as supported by their turbidity curves (Figure 7b). When it comes to temperature,

10

it is interesting to observe that the LS-PAE adhesive is more than simply surviving high

11

temperature conditions. Instead, the adhesion strength reached 623 ±48.5 KPa with increasing the

12

water bath temperature to 100 oC (Figure 8). Wet adhesives are relatively hydrophilic, and the

13

elevated temperature could enhance adhesive swelling and chain relaxation, both of which should

14

decrease adhesion strength.42–44 Here for LS-PAE system, the self-curing effect of azetinidium

15

groups could be enhanced at elevated temperature,45 which plays a major role dominating over the

16

negative effect of polymer swelling.


11


Page 12 of 18

1 2

Figure 7. (a) Adhesion strength of LS-PAE adhesive on glass substrates after underwater

3

deposition and 48 h conditioning in DI water and salty conditions (0.2M-1.0 M NaCl solution). (b)

4

Turbidity of LS-PAE complex at 0 M, 0.5 M and 1.0 M NaCl.

5

6 7

Figure 8. Adhesion strength of LS-PAE adhesives at elevated temperatures on glass substrate.

8

The adhesion of LS-PAE was tough and stable under both neutral and base conditions in a

9

30-day underwater soaking test (Figure 9). Mildly increased adhesion was observed at the first 10

10

days, followed by stable bonding performance over the rest of time. Due to the heterogeneous

11

aromatic structures, LS demonstrated improved structural stability over other biopolymers, such

12

as proteins and polysaccharides.46–49 Thus, in the presence of consecutively underwater soaking,

13

hydrolysis or degradation tended to weaken the adhesion strength for most bio-based adhesives,

14

while LS-PAE remained less affected.50,51


12

Page 13 of 18 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


1 2

Figure 9. Adhesion strength of the soaked LS-PAE was consecutively recorded from 0-30 day.

3

Glass was used as the substrate. Values in Day 0 are the adhesion strengths of LS-PAE cured in

4

water and pH 9 buffer from Figure 6a.

5

Conclusions

6

A waterborne and catechol-free strategy was proposed to prepare robust underwater adhesives by

7

exploiting a biomass pulping residues, lignosulfonate (LS) and an economic industrial additive,

8

polyamidoamine-epichlorohydrin (PAE-Cl). Upon solution mixing of LS and PAE-Cl,

9

electrostatic complexation and hydrophilic stabilization worked synergeticly to induce the fluidic

10

yet water-immiscible adhesive.The LS-PAE adhesive allows for instant underwater adhesion to

11

various substrates, and experiences spontaneous curing for substantially improved wet adhesion

12

strength. The wet adhesion was stable against pH (pH 6 ~ 10), increased salt concentration (1.0 M

13

NaCl), high temperature (100 ℃), and elongated soaking time (30 days). These properties are

14

benificial for practical applications and originated from the self-curing of PAE as well as the strong

15

complexation between PAE and LS. Collectively, the LS-PAE adhesive exquisitly integrated

16

value-added bioprocessing with high-performance underwater adhesion, and opened new doors to

17

the green and sustainable development of LS-based materials.

18

ASSOCIATED CONTENT

19

Supporting Information. The Supporting Information is available free of charge on the ACS

20

Publications website. The following files are available free of charge.


13


Page 14 of 18

1

Viscosity measurement of LS-PAE adhesive and commercial PVA glue, differential thermal

2

gravity and elemental analysis of LS, PAE and LS-PAE, in-situ underwater adhesion test of LS-

3

PAE adhesive, fracture surfaces of different bonding substrates.

4

AUTHOR INFORMATION

5

Corresponding Author

6

*E-mail: [email protected] (Q. Zhao).

7

Author Contributions

8

The manuscript was written through contributions of all authors. All authors have given approval

9

to the final version of the manuscript. ‡These authors contributed equally.

10

Notes

11

The authors declare no competing financial interest.

12

ACKNOWLEDGMENTS

13

The authors gratefully acknowledge financial support from the 1000 Young Talent program and

14

the Huazhong University of Science and Technology (No. 3004013118). Authors thank Prof. J.T.

15

Zhu (HUST) for generous help with turbidity measurements.

16

REFERENCES

17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35

(1) (2)

Heinzmann, C.; Weder, C.; Espinosa, L. M. De. Supramolecular Polymer Adhesives : Advanced Materials Inspired by Nature. Chem. Soc. Rev. 2016, 45, 342–358. Kim, K.; Shin, M.; Koh, M. Y.; Ryu, J. H.; Lee, M. S.; Hong, S.; Lee, H. TAPE: A Medical Adhesive Inspired by a Ubiquitous Compound in Plants. Adv. Funct. Mater. 2015, 25 (16), 2402–2410.

(3)

Ryu, J. H.; Hong, S.; Lee, H. Bio-Inspired Adhesive Catechol-Conjugated Chitosan for Biomedical Applications: A Mini Review. Acta Biomater. 2015, 27, 101–115.

(4)

Zhao, Y.; Wu, Y.; Wang, L.; Zhang, M.; Chen, X.; Liu, M.; Fan, J.; Liu, J.; Zhou, F.; Wang, Z. BioInspired Reversible Underwater Adhesive. Nat. Commun. 2017, 8 (1), 2218.

(5)

Nyarko, A.; Barton, H.; Dhinojwala, A. Scaling down for a Broader Understanding of Underwater Adhesives – a Case for the Caulobacter Crescentus Holdfast. Soft Matter 2016, 12 (45), 9132–9141.

(6)

Lee, B. P.; Messersmith, P. B.; Israelachvili, J. N.; Waite, J. H. Mussel-Inspired Adhesives and Coatings. Annu. Rev. Mater. Res. 2011, 41 (1), 99–132.

(7)

Kaur, S.; Weerasekare, G. M.; Stewart, R. J. Multiphase Adhesive Coacervates Inspired by the Sandcastle Worm. ACS Appl. Mater. Interfaces 2011, 3 (4), 941–944. Hofman, A. H.; van Hees, I. A.; Yang, J.; Kamperman, M. Bioinspired Underwater Adhesives by Using the Supramolecular Toolbox. Adv. Mater. 2018, 1704640, 1–38.

(8) (9)

Seo, S.; Lee, D. W.; Ahn, J. S.; Cunha, K.; Filippidi, E.; Ju, S. W.; Shin, E.; Kim, B. S.; Levine, Z. A.; Lins, R. D.; et al. Significant Performance Enhancement of Polymer Resins by Bioinspired Dynamic Bonding. Adv. Mater. 2017, 29 (39), 1–9.


14

Page 15 of 18 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44


(10)

Ahn, B. K.; Das, S.; Linstadt, R.; Kaufman, Y.; Martinez-Rodriguez, N. R.; Mirshafian, R.; Kesselman, E.; Talmon, Y.; Lipshutz, B. H.; Israelachvili, J. N.; et al. High-Performance MusselInspired Adhesives of Reduced Complexity. Nat. Commun. 2015, 6 (1), 8663.

(11)

Cholewinski, A.; Yang, F. (Kuo); Zhao, B. Algae–mussel-Inspired Hydrogel Composite Glue for Underwater Bonding. Mater. Horizons 2019.

(12)

Maier, G. P.; Rapp, M. V.; Waite, J. H.; Israelachvili, J. N.; Butler, A. Adaptive Synergy between Catechol and Lysine Promotes Wet Adhesion by Surface Salt Displacement. Science. 2015, 349 (6248), 628–632.

(13)

Ragauskas, A. J.; Beckham, G. T.; Biddy, M. J.; Chandra, R.; Chen, F.; Davis, M. F.; Davison, B. H.; Dixon, R. a; Gilna, P.; Keller, M.; et al. Lignin Valorization: Improving Lignin Processing in the Biorefinery. Science 2014, 344 (6185), 1246843.

(14)

Aro, T.; Fatehi, P. Production and Application of Lignosulfonates and Sulfonated Lignin. ChemSusChem 2017, 10 (9), 1861–1877.

(15)

Kai, D.; Tan, M. J.; Chee, P. L.; Chua, Y. K.; Yap, Y. L.; Loh, X. J. Towards Lignin-Based Functional Materials in a Sustainable World. Green Chem. 2016, 18 (5), 1175–1200.

(16)

Szabó, G.; Romhányi, V.; Kun, D.; Renner, K.; Pukánszky, B. Competitive Interactions in Aromatic Polymer/Lignosulfonate Blends. ACS Sustain. Chem. Eng. 2017, 5 (1), 410–419.

(17)

Kim, S.; Fernandes, M. M.; Matamá, T.; Loureiro, A.; Gomes, A. C.; Cavaco-Paulo, A. ChitosanLignosulfonates Sono-Chemically Prepared Nanoparticles: Characterisation and Potential Applications. Colloids Surfaces B Biointerfaces 2013, 103, 1–8.

(18)

Gillet, S.; Aguedo, M.; Petitjean, L.; Morais, A. R. C.; Da Costa Lopes, A. M.; Łukasik, R. M.; Anastas, P. T. Lignin Transformations for High Value Applications: Towards Targeted Modifications Using Green Chemistry. Green Chem. 2017, 19 (18), 4200–4233. Zhang, X.; Liu, W.; Yang, D.; Qiu, X. Biomimetic Supertough and Strong Biodegradable Polymeric Materials with Improved Thermal Properties and Excellent UV-Blocking Performance. Adv. Funct. Mater. 2018, 1806912, 1–11.

(19)

(20)

Hajirahimkhan, S.; Xu, C. C.; Ragogna, P. J. Ultraviolet Curable Coatings of Modified Lignin. ACS Sustain. Chem. Eng. 2018, acssuschemeng.8b03252.

(21)

Ushimaru, K.; Morita, T.; Fukuoka, T. Moldable and Humidity-Responsive Self-Healable Complex from Lignosulfonate and Cationic Polyelectrolyte. ACS Sustain. Chem. Eng. 2018, 6 (11), 14831– 14837.

(22)

Fredheim, G. E.; Christensen, B. E. Polyelectrolyte Complexes:  Interactions between Lignosulfonate and Chitosan. Biomacromolecules 2003, 4 (2), 232–239.

(23)

Rose, S.; Prevoteau, A.; Elzière, P.; Hourdet, D.; Marcellan, A.; Leibler, L. Nanoparticle Solutions as Adhesives for Gels and Biological Tissues. Nature 2014, 505 (7483), 382–385.

(24)

(25)

Huang, Z.; Gengenbach, T.; Tian, J.; Shen, W.; Garnier, G. The Role of PolyaminoamideEpichlorohydrin (PAE) on Antibody Longevity in Bioactive Paper. Colloids Surfaces B Biointerfaces 2017, 158, 197–202. American Society for Testing and Materials (ASTM) Standard D1002–10, 2010.

(26)

Dubin, P.; Stewart, R. J. Complex Coacervation. Soft Matter 2018, 14 (3), 329–330.

(27)

Clancy, S. K.; Sodano, A.; Cunningham, D. J.; Huang, S. S.; Zalicki, P. J.; Shin, S.; Ahn, B. K. Marine Bioinspired Underwater Contact Adhesion. Biomacromolecules 2016, 17 (5), 1869–1874.

(28)

Shao, H.; Bachus, K. N.; Stewart, R. J. A Water-Borne Adhesive Modeled after the Sandcastle Glue of P. Californica. Macromol. Biosci. 2009, 9 (5), 464–471.


15


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45

Page 16 of 18

(29)

North, M. A.; Del Grosso, C. A.; Wilker, J. J. High Strength Underwater Bonding with Polymer Mimics of Mussel Adhesive Proteins. ACS Appl. Mater. Interfaces 2017, 9 (8), 7866–7872.

(30)

Obokata, T.; Isogai, A. Deterioration of Polyamideamine-Epichlorohydrin (PAE) in Aqueous Solutions during Storage: Structural Changes of PAE. J. Polym. Environ. 2005, 13 (1), 1–6.

(31)

Chattopadhyay, S.; Keul, H.; Moeller, M. Synthesis of Azetidinium-Functionalized Polymers Using a Piperazine Based Coupler. Macromolecules 2013, 46 (3), 638–646. Gui, C.; Wang, G.; Wu, D.; Zhu, J.; Liu, X. Synthesis of a Bio-Based PolyamidoamineEpichlorohydrin Resin and Its Application for Soy-Based Adhesives. Int. J. Adhes. Adhes. 2013, 44, 237–242.

(32)

(33)

Ferdosian, F.; Pan, Z.; Gao, G.; Zhao, B. Bio-Based Adhesives and Evaluation for Wood Composites Application. Polymers (Basel). 2017, 9 (70), 1–29.

(34)

Kim, S.; Yoo, H. Y.; Huang, J.; Lee, Y.; Park, S.; Park, Y.; Jin, S.; Jung, Y. M.; Zeng, H.; Hwang, D. S.; et al. Salt Triggers the Simple Coacervation of an Underwater Adhesive When Cations Meet Aromatic π Electrons in Seawater. ACS Nano 2017, 11 (7), 6764–6772.

(35)

Chung, H.; Grubbs, R. H. Rapidly Cross-Linkable DOPA Containing Terpolymer Adhesives and PEG-Based Cross-Linkers for Biomedical Applications. Macromolecules 2012, 45 (24), 9666–9673.

(36)

Li, A.; Jia, Y.; Sun, S.; Xu, Y.; Minsky, B. B.; Stuart, M. A. C.; Cölfen, H.; von Klitzing, R.; Guo, X. Mineral-Enhanced Polyacrylic Acid Hydrogel as an Oyster-Inspired Organic–Inorganic Hybrid Adhesive. ACS Appl. Mater. Interfaces 2018, 10 (12), 10471–10479. Yuk, H.; Zhang, T.; Lin, S.; Parada, G. A.; Zhao, X. Tough Bonding of Hydrogels to Diverse NonPorous Surfaces. Nat. Mater. 2016, 15 (2), 190–196.

(37) (38)

Xu, J.; Li, X.; Li, X.; Li, B.; Wu, L.; Li, W.; Xie, X.; Xue, R. Supramolecular Copolymerization of Short Peptides and Polyoxometalates: Toward the Fabrication of Underwater Adhesives. Biomacromolecules 2017, 18 (11), 3524–3530.

(39)

Ahn, B. K.; Lee, D. W.; Israelachvili, J. N.; Waite, J. H. Surface-Initiated Self-Healing of Polymers in Aqueous Media. Nat. Mater. 2014, 13 (9), 867–872. Zhu, X.; Wang, D.; Li, N.; Sun, X. S. Bio-Based Wood Adhesive from Camelina Protein (a Biodiesel Residue) and Depolymerized Lignin with Improved Water Resistance. ACS Omega 2017, 2 (11), 7996–8004.

(40)

(41)

(42)

Dautzenberg, H. Polyelectrolyte Complex Formation in Highly Aggregating Systems. 1. Effect of Salt:  Polyelectrolyte Complex Formation in the Presence of NaCl. Macromolecules 1997, 30 (25), 7810–7815. Takanohashi, T.; Sato, S.; Saito, I.; Tanaka, R. Molecular Dynamics Simulation of the Heat-Induced Relaxation of Asphaltene Aggregates. Energy & Fuels 2003, 17 (1), 135–139.

(43)

Roland, C. M. Relaxation Phenomena in Vitrifying Polymers and Molecular Liquids. Macromolecules 2010, 43 (19), 7875–7890.

(44)

Sen, S.; Patil, S.; Argyropoulos, D. S. Thermal Properties of Lignin in Copolymers, Blends, and Composites: A Review. Green Chem. 2015, 4862–4887.

(45)

Obokata, T.; Isogai, A. The Mechanism of Wet-Strength Development of Cellulose Sheets Prepared with Polyamideamine-Epichlorohydrin (PAE) Resin. Colloids Surfaces A Physicochem. Eng. Asp. 2007, 302 (1), 525–531.

(46)

Mo, X.; Wang, D.; Sun, X. S. Physicochemical Properties of β and α’α Subunits Isolated from Soybean β-Conglycinin. J. Agric. Food Chem. 2011, 59 (4), 1217–1222.

(47)

Ma, L.; Yang, Y.; Yao, J.; Shao, Z.; Chen, X. Robust Soy Protein Films Obtained by Slight Chemical Modification of Polypeptide Chains. Polym. Chem. 2013, 4, 5425–5431.


16

Page 17 of 18 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38


(48)

He, M.; Lu, A.; Zhang, L. Advances in Cellulose Hydrophobicity Improvement. In ACS Symposium Series; 2014; Vol. 1162, pp 241–274.

(49)

Zhang, S.; Liu, T.; Hao, C.; Wang, L.; Han, J.; Liu, H.; Zhang, J. Preparation of a Lignin-Based Vitrimer Material and Its Potential Use for Recoverable Adhesives. Green Chem. 2018, 20 (13), 2995–3000.

(50)

Gogoi, S.; Karak, N. Biobased Biodegradable Waterborne Hyperbranched Polyurethane as an Ecofriendly Sustainable Material. ACS Sustain. Chem. Eng. 2014, 2 (12), 2730–2738.

(51)

Jenkins, C. L.; Siebert, H. M.; Wilker, J. J. Integrating Mussel Chemistry into a Bio-Based Polymer to Create Degradable Adhesives. Macromolecules 2017, 50 (2), 561–568.


17


Page 18 of 18

1

TOC:

2 3 4

Synopsis:

5 6

A green route to robust underwater adhesive was exploited through the lignosulfonate-based complex coacervation in water.


18

Facile Preparation of Lignin-Based Underwater Adhesives with

Recommend Documents