Self-healing additives in coatings

Shared research programme Thermal reversible covalent cross-links

Todays event

DanielHigh Temperature Self Healing

Industrial Parties present:

June 03, 20152

TEAM Diels-Alder:

Daniel Turkenburg

Jan Willem Slijkoord

Hartmut Fischer

Corné Rentrop

Background: • Self Healing coatings

• 15 years experience• Strong knowledge position in the Netherlands• Participation in various platforms (IOP, FP7, Horizon 2020)

• Common interest throughout the value chain: • Chemical companies,• Resins companies, • Paint companies, • End users

• Large interest in Diels Alder chemistry• 19 companies • 21 attendees• Interest from university, SME, Large Enterprise

Goal:

Defining Shared research project to boost Diels Alder chemistry in coatings applications

Focus points:

1. Shared Research programme

2. Diels Alder Chemistry

3. Utilisation in coatings

4. Involve total supply chain

Intermezzo: VitrimersThermoplast �� Thermohardener

Thermo-reversible polymer network

Agenda10.00: Welcome and goal meeting– Corne Rentrop

10.10: Who is Who? Introduction of all participants (name, company, role)

10.20: Status self-healing coatings & Diels Alder chemistry - Hartmut Fischer

10.50: Coffee break

11.10: Shared research: how does it work - Jan Willem Slijkoord

11.30: Interaction: Round table discussion to identify industrial needs – ALL

12.30: Lunch

13.00: Summary round table & project set-up – Corné Rentrop

13.45: Next steps - Jan Willem Slijkoord

Reversible Crosslinking – Other Applications

• SH COATINGS

• Recycling of plastics

• Encapsulants which open at elevated temperatures

• Changes in solubility/viscosity at high temperatures, sensorics,

• Thermally removable adhesives

• Reversible data storage medium…

• …

Status self-healing coatings & Diels Alder chemistry

Hartmut Fischer

Low temperature High temperature

Diels Alder chemistry Thermosetproperties at low temperature

Thermoplastic at high temperature so potential to recycle

Various methods to introduce in coating (Grafting to resin, (partially) replacing “traditional” curing, Use as and additive

Selection of materialsDiels-Alder

Furfuryl and Maleimide

Simple / commercially available

Aromatic / rigid structures

Windblade coating systems

Poly urethane

(Epoxy)

Furfuryl alcohol Bismaleimide

Diels-Alder

SolidPoor solubilityProne to side reactions

Careful consideration

Order of reactions

Conditions for each step

Activate selective reactions, butAvoid side reaction at high temperatures

HO – R - OH Isocyanante polyol

Stereochemistry of DA - reaction

Possible stereo-chemical configurations

Consequences for switching temperatures:

Self-repairing Materials –Thermally Re-mendable Cross-Linked Polymeric Materials

Use of a thermally reversible formation of covalent bonds to repair fractures upon heating of the structure until “disconnection” occurs and cooling to temperature of use where “re-connection” and healing occurs.

Reversible Diels-Alder reaction used for the crack healing mechanism

Result of the crack healing: Sample before after temperature treatment.

Partial recovery of the mechanics after repair.

O

R

N

O

O

R'O

R

N

O

O

R'

N

O

O

OR

O

O

O

N

N

O

O

O

R

O

O

O

N

N

O

OO

R

OO

O

N

N

O

OO

R

OO

O

N

N

O

O

O

R

O

O

O

N

N OO

O

R

O

OO N

+

‘Thermally re-mendable cross-linked coatings’Powder coating business case

Tunable properties of the binder material:

type & combination of monomers

concentration functional groups

molecular weight

CH3

C CH2

O

O O

O

O

CH2C

CH3

n m

+

Storage stability (glass transition temperature)

Processability (melt flow & wettability)

Mechanical properties (flexibility – hardness)

0246810δ (ppm)

CH3

C CH2

O

O O

O

O

CH2C

CH3

n m

1

1

2 & 3

2

3

4

4

5

7

6

CDCl3

66

78

9

10

5

5

8 9

10

* High concentration of monomer in the reaction mixture; 50wt% instead of 20wt%# Slightly different polymerisation procedure with respect to reaction time

Table 1 Copolymerisation of FMA and BMA Monomer

feed ratio: FMA:BMA

Mn PDI FMA composition from NMR

BMA composition from NMR

Tg

mol-% kg·mol-1 mol-% mol-% °C A 10:90 12.5 2.4 10 90 28 B 15:85 15.0 2.4 15 85 31 C 15:85 # 34.0 3.8 15 85 38 D 30:70 # 72.0 3.5 30 70 43 E 10:90 * 19.9 3.0 9 91 33 F 15:85 * 16.8 3.2 14 86 29


Tunable properties of the powder coating base material:

O

R

N

O

O

R'O

R

N

O

O

R'

N

O

O

OR

O

O

O

N

N

O

O

O

R

O

O

O

N

N

O

OO

R

OO

O

N

N

O

OO

R

OO

O

N

N

O

O

O

R

O

O

O

N

N OO

O

R

O

OO N

+

\

1E+2

1E+3

1E+4

1E+5

1E+6

1E+7

1E+8

0 50 100 150 200Temperature (°C)

Com

plex

vis

cosi

ty

(Pa.

s)

AB

CF

E

D


Comparison DSC analysis & rheology

1E+2

1E+3

1E+4

1E+5

1E+6

1E+7

1E+8

-50 0 50 100 150 200Temperature (°C)

Com

plex

vis

cosi

ty

(Pa.

s)

-0,3

-0,2

-0,1

0

0,1

0,2

0,3

Hea

tflow

(W

.g-1

)

Tg

DA

Application area corrosion protective powder coatings

High T

High T

N

O

O

O

Powder on aluminium Cross linked coating upon cooling

Marked with large scratch Cross linked coating with closed scratch

n mCH2 C CH2 C

CO

CH3 CH3

CO

O

C4H9

O

CH2

n mCH2 C CH2 C

CH3

CO CH3

CO

O

C4H9

O


Thermoreversible behaviour of the Diels-Alder system can be shown by means of rheological measurements: no deterioration of behaviour upon repetitive heating-cooling steps; test have been performed for at least 5 cycles …

1E+2

1E+3

1E+4

1E+5

1E+6

1E+7

1E+8

0 60 120 180time (min)

Com

plex

vis

cosi

ty

(Pa.

s)

25

75

125

175

Tem

pera

ture

(°

C)


Addition of pigment affects thermo-rheological behaviour

1E+2

1E+3

1E+4

1E+5

1E+6

1E+7

1E+8

0 50 100 150 200Temperature (°C)

Com

plex

vis

cosi

ty

(Pa.

s)

Material Synthesis:

TNO

Suprapolix

L’Urederra

Characterization:

University of Patras

University of Ioanina

www.Hipocrates-project.eu

Start: 2013 NovEnd: 2016 NovTotal budget: 2,8M€TNO budget: 250k€

Composites and

Mechanics:

University of

Bristol

Element

GMI

Application:

Inasco (database)

Aernova (planes)

Project Management:

Tecnalia

TNO approach

Combine mechanical properties of

highly crosslinked thermosetting

polymers…

… with thermo-reversible behavior

/processability of thermoplastic

systems …

… for fabrication of self-healing

fibre reinforced composites for

aerospace applications

Epoxy Chemistry

Diels-Alder Chemistry

Schematic overview of the process

Multifunctional

Monomers

Thermoset-like

PolymerThermoplastic-like

Polymer

Healed

Damaged

Key challenges:

Side-reactions

Viscosity

Compatibility / Stoichiometry

Curing / healing conditions

Including fibres

Heating

Varying the Crosslink density

Crosslink density depends on

Maleimide to Furfuryl ratio, r

r = 1highest crosslink density

r = 2, no crosslinks due to oversaturation

Effective chain length increasesCrosslinks start to form

Less groups available for crosslinking

# crosslink donors (X)

# crosslink acceptors (O)r =

Concentration of crosslinker expressed in rr = 0 r = 0,5 r = 1 r = 1,5 r = 2

Crosslink density – Solvent Swelling

The mass of a piece of polymer is determined before and after submersion in

dichloromethane for one day

Uncrosslinked material is dissolved in CHCl2, ∆m < 0

Loosely crosslinked material, flexibility to expand and absorb solvent voids, ∆m>0

Highly crosslinked material, dense and rigid, no room for solvent, ∆m = 0

Crosslink density – Rheology

Increase of concentration of

cross-linker:

Increase viscosity of liquid

state

Plateau of solid state is

broadened but remains at

the same height (mechanical)

Does not affect side-reaction

Prepolymer only does not have a

solid state plateau

Resin Mechanics

Test series #1

Material too strong for testing!

Self-healing material remains

Embedding host epoxy fails instead

Test series #2

As strong as benchmark

Successful multiple (3) self-healing events

Self-healing efficiency ~100%

N

O

O

O

R1

R

R2

O

O

O

N

SolidLiquid

Additive to introduce self-healing

Can be incorporated in “traditional” paints

Combined with novel resins (e.g. ionomers) to

enable thermoplast behaviour

>T

<T

Synthesis of additive

Results - rheology

Temperature cycle

Viscosity response

Coating without additive

Diels- Alder additive

Modified coating

Coating without additive

AdditiveIncreasing additive amount

Reversibele Crosslinking - Applications

• SH COATINGS

• Recycling of plastics

• Encapsulants which open at elevated temperatures

• Changes in solubility/viscosity at high temperatures, sensorics,

• Thermally removable adhesives

• Reversible data storage medium…

• …

Patents within TNO regarding DA -chemistry

US patent No. 9,051,480: Temporary functional finishes for textile applications, Principle:

using reversible DA to attach functionalities to surfaces with the option to change surface

character and/or to restore surface functionality

WO 2012044160 A1: An active carrier for carrying a wafer and method for release based

on DA Chemistry

WO 2010044661 A1: Recycling an organic-matrix composite material; binder of composite

with reversible x-links based on DA-chemistry

WO 2004076567 A1: Low solvent coating process for applying the coating to an object

coated object obtainable with the process and process for levelling a coating applied to an

object

Shared Research: How does it work?

Jan Willem Slijkoord:

Contents

J.W. Slijkoord/Sander Gielen dd. May 20th 2015

Shared Research participation fee and entrance fee

IP model, IP ownership & User rights

Steering Group Meeting procedure

Confidentiality

Why this self-healing shared research program?


• Development approach of shared research programs characterized by the

• Development of generic technology requiered for all participants

• Development of company specified self-healing demonstrators

• Reduced R&D risks:

• by group of participants rather than by one company only

• Accelerated innovation by agile shared research approach

• Parallel program work packages

• Application foreground IP by participants active in the coatings value chain

TNO has long-term track record in shared research p rograms


Holst Center: Shared Research in flexible electronics

Since 2005

38 industrial companies

Joint Industrial Program “Sustainable Chemical Product Performance”

Project since 2015


Joint Industrial Program “Stress Relaxation Cracking”

Project since 2013


27-7-2015

Some of our Industrial Partners…

Shared Research Participation & Entrance Fee (1/2)

TNO & company background R&D and IP

Self Healing Additives Shared Research Program

Company YParticipation fee +

(optional) entrance fee

Start End

Company XParticipation fee

Shared Research Participation & Entrance Fee (2/2)

TNO & company background R&D and IP

Self Healing Additives Shared Research Program

Company YParticipation fee +

(optional) entrance fee

Company XParticipation fee

• Indication participation fee per participant: 25 kEUR.

• Final participation fee can be lower or higher, dependent on desired:

• IP Domain range wide or limited

• Voting rights

• More or less demonstrators to be delivered

• In case participants will join the program, TNO will actively seek

precompetitive financial leverage of the project

IP model for Shared Innovation


Shared

IP Ownership & User rights in the self healing program


• TNO will be owner of foreground IP in Self Healing Additives Research Program

• All participants will get an non-exclusive user right within the agreed application domain

The steering group meetings during the program:Role & Responsibility (1/2)

Role Steering Group = monitor results & influence p rogram

• Steering group is decision making entity.

• It evaluates intermediate results & makes decisions about the future R&D activities in

the program and other relevant decisions, such as:

Changes to original research plan and suggestions for successive research

Publication of (intermediate/final) reports

Specification of demonstrators

Entry of new participants


The steering group meetings during the program:Role & Responsibility (2/2)

Main responsibilities of the steering group:

- Guide the development for self healing additives

- Evaluate interim and final results of the research programme

- Agree on the research programme activities for the next 6 months


Voting & decision making during steering group meet ings

Voting

Each participant has one vote, irrespective of the number of representatives

Decisions shall be taken with at least two-thirds of the votes

TNO scientifically responsible chair

TNO is chairman of the steering group meetings

TNO will prepare decisions to be taken, so has NO vote.

TNO is NOT a program participant but the scientifically responsible chair

SCPP kick-off meeting

Public

Confidentiality

TNO will

Not reveal or publish member’s confidential information, without its prior

written approval

Reveal or publish any results only with approval of the steering group

Participants

Any objection of publication or other release of IP is justified if the

protection of the member’s confidential information is adversely affected

SCPP kick-off meeting

Steering group

TNO – Cie1-1

confidentiality

47

Further questions about participation & commercial issues?

Please Contact:

Mr. J.W. Slijkoord MSc.

Business Development Mgr

Mail: [email protected]

Phone: +31 (0)6 51 81 34 93

Summary: Project set up

Corné Rentrop

:

Project set-up

Phasing: TNO foresees 4 phases for Self-healing coatings based on Diels Alder

technology.

1) Coating systems identification and design of DA Additive

2) Synthesis of DA additive

3) Introduction DA additive into coating systems and coatings

evaluation

4) Upscaling of the DA additive to pilot scale

Phase 1: Coating systems identification and design of DA Additive

Activity:

� Every participating coating manufacturer has the opportunity to

define a coating chemistry (epoxy, alkyd, polyurethane, … ) for

possible addition of the DA additive.

� In close cooperation with the coating manufacturers and chemical

suppliers a suitable design for the DA additive will be made.

� The design will be based on the targeted flexibility and

compatibility with the coating system, the state of the art cross-

linking chemistry in the formulation, and the targeted de-coupling

temperature depending on the coating application .

Phase 1: Coating systems identification and design of DA Additive

Result:

� Theoretical design of DA additives for each coating manufacturer/ and coating system

� Additive that is producible by chemical companies

� Mutual meeting with all partners sharing results.

Phase 2: Synthesis of the DA Additive.

Activity

� Each DA additive as proposed in Phase 1 will be synthesized.

� A first order compatibility study will be executed with the targeted

coating system

� Characterisation of the Diels Alder additive

� E.g. indication of the de-coupling temperature and self-healing

characteristics.

� Optimising the Diels Alder additive design

Phase 2: Synthesis of the DA Additive.

Result:

� Small scale samples of the DA additive for evaluation purpose at

TNO

� Model coatings including the Diels Alder additive.

� Report describing the synthesis of the Diels Alder additive and a first

order evaluation of the self-healing characteristics of the resulted

coatings

� Mutual meeting with all partners sharing results.

Phase 3: Introduction of the DA Additive into the coating systems and coatings evaluation

Activity

� The best performing DA additives from phase 2 are synthesised on a

larger scale .

� The DA additive is distributed to the coating manufacturers.

� Coatings are formulated at the manufacturers laboratories using a

model recipe.

� Coating manufacturers will optimise performance (loading,

crosslinking, resin).

� Pigmentation and other coating formulations is also done at the

coatings manufacturers to study the effect of these ingredients on

ultimate performance.

� Evaluation is focussed on the targeted self-healing properties and

typical coating properties (thickness, adhesion, UV stability).

Phase 3: Introduction of the DA Additive into the coating systems and coatings evaluation

Results:

� DA additives on a larger scale

� First order recipe to create the self-healing coatings

� Self healing coatings created by the coatings manufacturers

� Evaluation report of the coatings

� Mutual meeting with all partners sharing results

Phase 4: Upscaling of the DA additive to pilot scale (Designed for Chemical suppliers).

Activity

� The recipe of a suitable DA Additive (results of phase 1 and 2) is

supplied to an additive manufacturer

� The manufacturer produces the additive on a larger scale.

� Materials is supplied to phase 3

� Iterations on DA additive

Phase 4: Upscaling of the DA additive to pilot scale (Designed for Chemical suppliers).

Results:

� Demonstration of a DA additive available on pilotscale (e.g. kg scale)

� Evaluation report of the DA additive

� Mutual meeting with all partners sharing results

Project phasing

Set of demands:• Clustering• Additive design

Synthesis of DA additive

Introduction in coatings systems

Upscaling of Diels Alder

additive

1 year Evaluation

no. Participant Country Organisation Type1. Rapra UK LE 2 Fraunhofer ICT D RTD 3 TNO NL RTD 4 EDAG D LE 5 Archimedes Polymer CY SME 6 PPG NL LE 7 Norner AS N SME 8 Comfil ApS DK SME 9 Loiretech SAS F SME 10 Coriolis Composites SAS F SME11 NEN NEderlandse Norm NL Association NEN

Automotive

Self-healing additives in coatings