Graphene Related Materials for Elastomer Nanocomposites

Silvia Guerra, Luca Giannini, Luciano Tadiello, Vincenzina Barbera, Maurizio Galimberti PIRELLI - R&D PLATFORM

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33 collaboration projects with University 20 JDAs and more than 50 NDAs with suppliers/universities Over 100 co-operations with Premium OEMs projects on cutting edge technology Unique motorsport know-how

Over 150 external projects on Materials, Process, Software and Electronics ~ 6,500 patents as of 2018 year end ~6.5% of High Value revenues devoted to R&D in the last three years

1. Modular Integrated Robotized System

Silvia Guerra, Polychar 27 world forum on advanced materials “ Copyright Pirelli Tyre SpA 2019 Tyre Insight

Tyre looks just black and round....

...but hides significant complexity in macro-components and in materials, down to the nano- scale

Tyre macroscopic performance depends critically on compounds properties at lengthscales spanning 7 orders of magnitude from cm to nm

Silvia Guerra, Polychar 27 world forum on advanced materials “ Copyright Pirelli Tyre SpA 2019 Tyre Insight: Nanoscale Compound’s Structure

Chemicals Polymer

Curing agent

Tyre Compunds = Nanocomposites NanoFillers  Polymers and Nanofillers are essential part of all Rubber Compounds  Chemicals can modify the interactions between Polymers and Fillers  The overall performance depends on the collective behaviour of all components

Silvia Guerra, Polychar 27 world forum on advanced materials “ Copyright Pirelli Tyre SpA 2019 Nanomaterials as (new)fillers in Rubber Technology: Overview

Chemical Nature Dimensionality Expected Performance

 Polyhedral Oligomeric Mechanical Properties Silsesquioxanes (POSS) 3-D (Low Hysteresis) at Nanoscale  Nano Oxides (Silica, Allumina)

High Aspect Ratio Nanofillers

 Modified Silicates Mechanical  Carbon Nano Tubes (SWNT & 2-D MWNT) Properties at Nanoscale (High Modulus)  Polymeric Nanofibers

 Graphene Related Materials Mechanical Properties  Clays (Montmorillonite) 1-D + at Nanoscale  Zirconium Phosphates Barrier Effect

Silvia Guerra, Polychar 27 world forum on advanced materials “ Copyright Pirelli Tyre SpA 2019 Nanomaterials as fillers in Rubber: Carbon-based Nanomaterials

Sample Surface area Number (m2/g) of layers

HSAG 330 35 GNP 750 26 CNT 200 9 CB 80 5

XRD

Debay Scherrer equation

20.3nm (35 layers) = D 002

Silvia Guerra, Polychar 27 world forum on advanced materials “ Copyright Pirelli Tyre SpA 2019 Nanomaterials as fillers in Rubber: Carbon-based Nanomaterials

Carbon Nanomaterials from a layer of sp2-bonded carbon atoms graphene

piled wrapped

graphite CNT piled randomly arranged

Grades carbon black with different shape anisotropy

d002 = 0.354 nm

c = 0.671 nm

Silvia Guerra, Polychar 27 world forum on advanced materials “ Copyright Pirelli Tyre SpA 2019 [New] Materials for new Products: Multifunctionality

GRAPHENE

MWCNT

CARBON IMPERMEABILITY BLACK ELECTRIC CONDUCTIVITY Multi Functionality REINFORCEMENT

PRICE/DIFFICULTY IN MAKING

Silvia Guerra, Polychar 27 world forum on advanced materials “ Copyright Pirelli Tyre SpA 2019 Graphene in Tyre Patent Trend

⇒ About 500 patents per year ⇒ About 40 patents per year regarding Graphene(graphite) and regarding Graphene(graphite) and Elastomers Tyres

Silvia Guerra, Polychar 27 world forum on advanced materials “ Copyright Pirelli Tyre SpA 2019 Graphene in Elastomers - Patent highlights

Functional targets:  Mechanical reinforcement  Electrical & Thermal Conductivity  Impermeability

Material focus:  Graphene/graphite functionalization  Polymer matrix Functionalization

Applications:  Sensors and «elctronic devices»  Products with better mechanics  Product-related improvements – e.g. for tyres: o Impermeability of inner-liner to keep air and garantee constant performance o Electrical conductivity for static charge dissipation o Heat management to improve curing and avoid blistering

Silvia Guerra, Polychar 27 world forum on advanced materials “ Copyright Pirelli Tyre SpA 2019 From Materials to Performance Targets

vs

GNPs CB N326

(Graphene nanoplatelets) (Carbon Black)

Mechanical and electrical properties

Silvia Guerra, Polychar 27 world forum on advanced materials “ Copyright Pirelli Tyre SpA 2019 From Materials to Performance Targets: mechanical and electrical properties

vs

4,5 GNPs CB N326

4 1E+07 GNPs 3,5 1E+06 1E+05 3 CB 1E+04 GNPs CB 2,5 1E+03

2 sigma unfilled 1E+02 σ

(at 0.1Hz) 1E+01 % (filled/unfilled) (filled/unfilled) % 1,5 1E+00 1 filled/ 0.7 1E-01 0,5 σ 0 10 20 30 40 50 G'' 0 phr 0 10 20 30 40 50 phr  Better mechanical and electrical properties of GNPs compared to CB N326  Mechanical percolation threshold and electrical percolation threshold firstly achieved for GNPs S.Guerra, PhD Thesis. Poltecnico di Milano

Silvia Guerra, Polychar 27 world forum on advanced materials “ Copyright Pirelli Tyre SpA 2019 Natural rubber/GNPs composites from NR latex

 Latex blending is acknowledged as the best mixing procedure for obtaining the best dispersion of a filler

GNPs

 Introduction of polar groups on carbon allotropes

Oxidation

Silvia Guerra, Polychar 27 world forum on advanced materials “ Copyright Pirelli Tyre SpA 2019 Natural rubber/GNPs composites from NR latex

 Latex blending is acknowledged as the best mixing procedure for obtaining the best dispersion of a filler

GNPs

 Introduction of polar groups on carbon allotropes

Oxidation Staudenmaier’s or Hummers’ methods Problems

Strong acids and oxidation agents Potentially, they might be dangerous reactions Problematic work-up: removal of acids and metal (Mn) oxides

Silvia Guerra, Polychar 27 world forum on advanced materials “ Copyright Pirelli Tyre SpA 2019 Synthesis of SP

 To perform functionalization reactions inspired to the principles of green chemistry, ideally by using biosourced chemicals. OH HO OH glycerol

Chemistry Batterica (E. Coli)

NH2 HO OH Sugar cane Serinol

OH O ∆ NH O N O 2 - N 2 H O O 2 HO OH OH Neat Reaction Conditions: T = RT - 180°C t = 25 - 360 min 2-(2,5-dimethyl-1H-pyrrol-1-yl)-1,3-propanediol (serinol pyrrole, SP) Adduct of Graphene nanoplatelets and SP

N + HO OH

GNPs SP BET = 700 m2/g Thermal energy

GNPs-SP adduct

 Quantitative functionalization yield  Reaction does not substantially alter the bulk crystalline order of the carbon allotrope

Galimberti, M., Barbera, V., Sebastiano, R., Citterio, A., Leonardi, G. WO/2016/050887 A1 (2016) V. Barbera, A.Citterio, M. Galimberti, G. Leonardi, R. Sebastiano, S.U.Shisodia, A.M. Valerio WO 2015 189411 A1 Galimberti, M., Barbera, V., Guerra, S., Conzatti, L., Castiglioni, C., Brambilla, L., & Serafini, A. (2015). Biobased Janus molecule for the facile RSC Advances

Silvia Guerra, Polychar 27 world forum on advanced materials “ Copyright Pirelli Tyre SpA 2019 NR/GNPs -SP composites from NR latex N HO OH

NR latex

+ sonication 30′ GNP-SP H2SO4 NR/GNPs-SP latex dispersion composite GNP-SP water dispersion

Graphene platelets around rubber particles. Percolation at low concentration of graphitic material

Potts, J. R., Shankar, O., Du, L., & Ruoff, R. S. (2012 Macromolecules, 45(15), 6045-6055.

S.Guerra, PhD Thesis. Poltecnico di Milano Galimberti, M., Barbera, V., Guerra, S., & Bernardi, A. (2017). Facile functionalization of sp2 carbon allotropes with a biobased Janus molecule. Rubber Chemistry and Technology, 90(2).

Silvia Guerra, Polychar 27 world forum on advanced materials “ Copyright Pirelli Tyre SpA 2019 NR/GNPs -SP composites from NR latex N HO OH

 stacks of few layers graphene

 isolated layers

X-Ray diffraction Transmission Electron Microscopy

NR /adduct 100/10 Adduct GNP-SP Poor stacking of graphene layers

S.Guerra, PhD Thesis. Poltecnico di Milano Galimberti, M., Barbera, V., Guerra, S., & Bernardi, A. (2017). Facile functionalization of sp2 carbon allotropes with a biobased Janus molecule. Rubber Chemistry and Technology, 90(2).

Silvia Guerra, Polychar 27 world forum on advanced materials “ Copyright Pirelli Tyre SpA 2019 Adduct of SP with Carbon black

CBN326 carbon black + Energy: mechanical, thermal

Water suspension of CB/SP

10′ sonication, analysis at time 0 10′ sonication, analysis after 3 days

5′ centrifugation at 9000 rpm/min

Silvia Guerra, Polychar 27 world forum on advanced materials “ Copyright Pirelli Tyre SpA 2019 NR-BR / CB-SP / silica composites

Ingredients phr phr

IR 50 50 CB-SP was used as compatibilizer of CB and silica

BR 50 50 CB N326 25 20 0 5 CB/SP melt blending IR-BR/CB-SP (or CB) IR-BR/CB-SP(or Silica1165 25 25 composites CB)/silica Silane TESPT 2 2 composites + Stearic acid 2 2 silica ZnO 2,5 2,5 6PPD 2 2 TBBS 1,8 1,8 Sulphur 1,5 1,5

totale 161,80 161,80

Silvia Guerra, Polychar 27 world forum on advanced materials “ Copyright Pirelli Tyre SpA 2019 NR-BR / CB-SP / silica composites

CB CB CB-SP CB-SP

-Composite with CB-SP shows lower modulus at lower strain and lower G’’ modulus for a given G’ modulus: Less filler networking

-Crossover of (G’ vs strain) curves:

Stronger polymer-filler interaction with CB-SP Galimberti, M., Barbera, V., Guerra, S., & Bernardi, A. (2017). Facile functionalization of sp2 carbon allotropes with a biobased Janus molecule. Rubber Chemistry and Technology, 90(2), 285-307.

Silvia Guerra, Polychar 27 world forum on advanced materials “ Copyright Pirelli Tyre SpA 2019 Graphene Related Materials for Elastomer Nanocomposites  Graphene Related Materials for Elastomer Nanocomposites are an active field of Research and Development both in academic and in industrial environments

 Target Nanocomposite functionalities in Elastomers include  Mechanical Reinforcement  Electrical and Thermal Conductivity  Impermeability

 The main Technical Challenge to achieve the potential performances of Nanocomposites featuring fillers is DISPERSION and INTERFACE Control  Functionalization of Graphene, Polymers and other fillers are envisaged

 In the frame of an open Innovation R&D Model, Pirelli developed with its Academic Partners a functionalization approach based on a partially renewably sourced molecule, with promising initial results

Silvia Guerra, Polychar 27 world forum on advanced materials “ Copyright Pirelli Tyre SpA 2019 Thank you!

Silvia Guerra Material Advanced Research [email protected]