Effect of stearic acid coated coconut shell powder on

Effect of stearic acid coated coconut shell powder on vulcanization and mechanical properties of natural rubber composites D.E. Prematunga,

[1]

C. Sandaruwan,

[1]

[2]

and U.N. Ratnayake

[1] Sri Lanka Institute of Nanotechnology (SLINTEC), Lot 14, Zone 01, Biyagama Export Processing Zone, Walgama, Malwana, Sri Lanka [2] Rubber Research Institute Telawala Road, Ratmalana, Sri Lanka

Rubber Fillers

Results and Discussion

Coconut Shell Powder (CSP) Coconut shell powder is hard material, containing 2 biopolymers; Lignin Cellulose.

SEM image of CSP powder

• Reinforcing fillers - Improve the mechanical properties (e.g. Carbon black, Silica) • Non-reinforcing fillers - As a material to fill the bulk (e.g. Calcium Carbonate)

Vulcanization Parameters

SEM image of NRCSP

Conclusions Due to coating of stearic acid on coconut shell powder, the dispersion and the wettability of CSP has improved in the rubber matrix

These two polymers provide the rigidity and the toughness to the coconut shell powder

Materials and Mvethod Mechanical Properties

The scorch time and optimum cure time increases due to free stearic acid available which acts as a plasticizer Smaller particle size and improved coating of stearic acid may lead to improved mechanical reinforcement

Referances IPPD - n-isopropyl-n'-phenyl-n-phenylenediamine MBTS - Mercaptobenzothiazole disulphide

Stearic acid coated CSP CSP with particle size of 10 – 15 µm Coated with 10% of stearic acid to improve the compatibility Mixed with CSP uniformly Heated to 85 0C for 1 hour Grinded to yield a homogenized coating

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