International Conference on Sustainable Built Environment

NANCO AND UNIVERSITY OF MELBOURNE JOINT RESEARCH SESSION ON NANOTECHNOLOGY AND SUSTAINABLE BUILT ENVIRONMENT

13-14 December, 2010 at Earls Regency, Kandy, Sri Lanka

NATURAL RUBBER/LAYERED SILCATE NANOCOMPOSITEFOR BUILDING APPLICATIONS

T.C. Peiris (BSc Eng, MSc)

U.N. Rathnayake (PhD. Loughborough)

Outline

Conventional rubber composites

Importance of nanotechnology

Feasible nanomaterial and processing with it

Results and discussion

Future directions

Key applications in construction industry:

Conventional rubber composites

- Tires/Tracks

- Load bearings (Bridge bearings, Fenders, etc.)

- Bushes, Mounts, Floorings

- Hoses, Belts, Rollers, Sheets, etc.

Rubber/s +

Carbon black/Silica

Requirements:

Conventional rubber composites Contd.

- A reinforcing material from non-polluted route

- Non- petroleum product

- Cost effectiveness

- Non- hazardous to process

Is there a material to replace Carbon black?

- If so,

Advantages of Rubber nanocomposites (RNCs)

Importance of nanotechnology

- Improved mechanical properties at very low loading levels of nanomaterials

- Substitute for Rubber / Carbon black or Silica composites

Inert materials reinforcing fillers

- Improved barrier properties

- Improved thermal stability

Montmorillonite (MMT):

Feasible nanomaterial & processing with it

- Inorganic layered silicate

- Provides easy surface modification

- In-situ nanofiller formation via:

- Intercalation and exfoliation of MMT

Preparation of RNCs:

- Solution intercalation

- In-situ polymerisation

- Latex route

- Melt blending (Banbury and two-roll mixing)

Paul D.R., Robenson L.M. Polymer nanotechnology: nanocomposites, Journal of Polymer 49 (2008) 3187-3204

Preparation of Natural rubber NCs through melt blending:

Feasible nanomaterial & processing with it Contd.

- By organically modifying the MMT (i.e. OMMT)

- By incorporating polar additives to the rubber

1) Compatibility between the rubber and the MMT

- By optimising the shear level during the mixing

- By optimising the processing time, temperature

2) Adjusted processing parameters

Thereby achieving maximum intercalation and exfoliation

Intercalation and exfoliation

Feasible nanomaterial & processing with it Contd.

Paul D.R., Robenson L.M. Polymer nanotechnology: nanocomposites, Journal of Polymer 49 (2008) 3187-3204

Results & discussion

NRGUM

NRLS4 NRLS8 NRLS10 NRLS4/90 NRLS10/90 NRLS15/90 NRCB30/90

NR 100 100 100 100 100 100 100 100OMMT - 4 8 10 4 10 15 CB 30Polar additive - 0.46 0.92 1.15 0.46 1.15 1.73 -CaCO3 - - - - 90 90 90 90ZnO 5 5 5 5 5 5 5 5Stearic acid 1 1 1 1 1 1 1 1IPPDa 1 1 1 1 1 1 1 1Sulphur 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5MBTSb 1 1 1 1 1 1 1 1

Several compounds were prepared

- All values are in phr (parts per hundred parts of rubber)

Vulcanisation characteristics

Results & discussion Contd.

X-ray diffractometer analysis

- Target: for no-peak situation

Results & discussion Contd.

Two theta

Results & discussion Contd.

SEM image of cured NRLS4

Intercalation and exfoliation

Feasible nanomaterial & processing with it Contd.

N+2R

Results & discussion Contd.

Tensile strength and Modulus

Compound Hardness(Shore A)

Tensile strength

(MPa)

Modulus-300%(MPa)

Tear strength(KN/m)

Elongation(%)

Compression set(%)

Rebound resilience

(%)

NR-gum 31.75 13.15 0.99 29.15 726 80

NRLS4/90 55.92 19.14 5.75 42.01 557 7.22 72

NRCB30/90a 59.50 15.56 5.95 33.35 521 12.08 60

PROPERTIES ASTM STANDARDS REQUIRED

T.S.(Mpa) D 412 15.6

Elongation at Break % D 412 >350

Hardness (Shore A) D2240 60 (±5)

Compressive set % D395 35

*Engineering with rubber : how to design rubber components / Alan N.** http://pretread.com/

Results & discussion Contd.

- Bridge bearings * - Required properties for bridge bearings**

Future directions

- Preparation of NCs with 100% exfoliation

- Preparation of NCs by rubber blends

- Further improvements along barrier properties & thermal stability

- Improvements towards functional materials (antistatic,

electrical, magnetic or hybrid etc.)

Acknowledgement

Prof. Ajith De Alwis & Prof. Veranja karunarathne for the leadership given

Team NANCO

Loadstar Pvt, Ltd

Thank you …