Presentation at NEA Workshop on “Sustainable Design of and Value Recovery from Plastics”

Sustainable Application of Plastic Materials

Chaobin HeNational University of Singapore & Institute of Materials Research and Engineering, A-star

Plastics and Plastics Waste are Everywhere

Locally at Singapore in 2017:

The key plastic wastes are: Polyethylene terephthalate (PET), Polypropylene (PP), Low-density polyethylene (LDPE), and High-density polyethylene (HDPE).

Sorted plastic are cut into pellets to be used as material for manufacturing new products

Of 815,200 tonnes of plastic waste were generated in 2017, with only about 6% being recycled. The plastics that were not recycled were incinerated.

Plastics and Plastics Waste are Everywhere

If not properly recycled and reused, plastic will end up here

Disturbing footage shows fish found

with stomach full of plastic. The

Golden Fish was found off the waters

of Costa Rica

Pollute our environment

Enter our food chain

Outline Technology and Approaches

1.Up Cycling of PP/PE Wastes2.Enhanced the Property of PP/PE Waste

Using Additives

Approach 1: Up Cycling of PP/PE Wastes--Fiber Reinforced Composite Structure for Electrical Car

Opportunity

Light Weight and High Strength Composite Material is an important factor for structural component of E-car; while the temperature requirement of E-car is much lower than combustion engine car. PP/PE with suitable modification could potential be used.

In future, PP could be used to replace PA66 for electrical car application where the temperature requirement is much lower.

Approach 1: Up Cycling of PP/PE Wastes--Fiber Reinforced Composite Structure for Electrical Car

ChallengesProperties of recycled polymers suffers significant decline each time it is being recycled and the compatibility between recycled thermoplastic matrix and fibers compounds this problem.

Research Strategy1. Develop an effective method to improve the

compatibility between recycled thermoplastic matrix and fibers

2. Study on the effect of processing conditions and various modifications on morphologies, mechanical properties, thermal properties of composite materials will be conducted.

3. Energy consumption and carbon footprint of the composite will be compared with that of virgin thermoplastic composites.

Thermoplastic Taps

Approach 2: Enhancing Performance of Recycled

Polypropylene Using Low-Cost Functional Fillers

• Polypropylene (PP)

– High-volume plastic waste

– Prone to thermo-oxidation → molecular weight reduction in melt

recycling process → poor impact resistance of recycled PP

– Recycled PP is more prone to UV-induced degradation (most anti-

oxidants had been consumed after long-term usage)

– Some inorganic fillers may act as catalyst to induce PP degradation

• Objectives

– To improve mechanical performance of recycled PP

– To utilize low-cost additives and fillers in high-value products

• Approaches

– Use low-cost functional additives to slow down PP degradation

– Reinforce PP with low-cost inorganic fillers without sacrificing toughness

Lignin from pulp as multifunctional fillers

Efficient anti-oxidants

Efficient UV-stabilizer

Effective toughening agent

Low cost

Sustainable

No need for separation

in recycling

• Potential applications

For molding household goods, equipment housings, etc.

• Target partners

Resin suppliers, plastic additive manufactures, end users

• An example

Thanks