National Technical University of Athens

School of Chemical Engineering

Polymer Technology Lab.

RECYCLING AND REUSE OF PLASTICS

CONTAINED IN WASTE FROM

ELECTRICAL AND ELECTRONIC EQUIPMENT

Μ.Ι.Triantou, P.A.Tarantili, A.G. Andreopoulos

2nd International Conference on Sustainable Solid Waste Management, Athens, Greece, 12-14 June, 2014

World plastics production 1950-2012Source: Plastics Europe-Plastics – The Facts 2013: An analysis of

European latest plastics production, demand and waste data

European plastics demand by segment 2012Source: Plastics Europe

Plastics production and demand

Global production of plastics in 2012 rose to 288 million tones – a 2.8% increase compared to 2011.

In Europe, in line with the general economic situation, plastics production decreased by 3% from 2011 to 2012 reaching 57 million tones.

In 2012: demand in Europe decreased by 2.5% and

reached 45.9 million tones, the electrical and electronic equipment sector

covered the 5.5% of the european plastics demand.

2

Disposal, recycling and energy recovery

of plastics in 2012 in Europe

(Source: Plastics Europe)

Waste management of plastics

The total recovery of plastics increased by 4% in 2012 (mechanical recycling increased by 4.7%, energy recovery increased by 3.3%).

At the same time, there was a reduction of 5.5% of landfilled plastics.

Total plastics waste recycling and recovery 2006-2012 in Europe(Source: Plastics Europe)

Treatment of post consumer plastics waste 2012 by

EU-27+2 (Source: Plastics Europe)

In Greece, recycling and energy

recovery rates are still at low values.

3

Waste management of EEE

The waste coming from EEE represents an about 8% of the total municipal waste internationally.

In European Union, 12-20 kg WEEE/habitant is produced each year and their overall, annual production varies between 6.5-7.5 million tones [Hellenic Solid Waste Management Association].

In Greece, 170.000 tones WEEE are produced per year [Hellenic Solid Waste Management Association]. During 2005-2013 (1st semester), the 87.73% of EEE was treated, whereas the 12.27% was

led to landfill in Greece [Appliances Recycling S.A.].

Total exploitation of WEEE (tones) and separate collection WEEE from

domestic sector (kg/habitant) during 2005-2012 in Greece

(Source:eoan -Report of recycling in Greece, September 2013, Athens, 18-22)

33411 tones

exploited

4

Composition of WEEE

47,90%

20.60%

7%

5,40%

4,70%

4,60%3,10%

2,60% 2% 1% 0,90%

iron-steel

plasticscopper

glass

aluminium

other

circuits

wood

ceramics

other metals

rubberComposition of WEEE (Source: Hellenic Solid Waste

Management Association)

Packaging dominates the waste generated from plastics, covering 62.2% of the total. Other applications like building and construction, electrical and electronic products and agriculture count for 5 till 6% each [Plastics Europe] .

Source: WRAP, 2009

Generation of post-consumer plastics

waste by application (Source: Plastics Recyclers Europe)

ACR

6%

PA

4%

PEP

3%

HIPS

2%PET

2%POM

2%

PE

2%PVC

2%Άλλα

4%

DMPS

3%

PB

3%

PC/ABS

3%

ABS

20%

PP

10%

PS

12%PC

11%

SAN

10% 5

Materials

ABSABS

PPPCCl30B Cl30B

Poly(acrylonitrile-butadiene-styrene) terpolymer, ABS (Terluran GP-35, BASF)

Polycarbonate, PC (Makrolon 2805, Bayer)

Polypropylene, PP

Cloisite 30B (OMMT) (Rockwood Clay Additives GmbH)

2 phr

100/0

70/30

50/50

30/70

0/100

2 phr

ABS PC Cloisite 30B

Organic modification

of Cloisite 30B

PP 6

contributes to the

improvement of

properties of blends

acts as a compatibilizer

between the

components of blend

a low-cost, ecological additive

Experimental procedure

Pre-mixture

Melt intercalation (co-rotating, twin screw extruder)

Granulation Injection

Melt Flow Index

(MFI)

Thermogravimetric

Analisis (TGA)

Gross Calorific

Value (GCV)

Tensile

testDynamic Mechanical

Analisis (DMA)

7

Melt Flow Index (MFI)

The incorporation of organoclay into the ABS/PC blends results in a decrease of the MFI, maybe due to the confinement of polymer chains motion, caused by organoclay platelets and tactoids, and the interactions between the polar groups of ABS and oxygen containing groups of Cloisite 30B.

The MFI of ABS/PP blend tends to be decreased by incorporating OMMT.

70/30 50/50 30/700

2

4

6

8

10

12

14

16

18

MF

I (g

/10

min

)

ABS/PC (w/w)

0 phr Cl30B

2 phr Cl30B

PC

100/0 70/30 50/50 30/70 0/1000

1

6

8

10

12

14

16

MF

I (g

/10

min

)

ABS/PP (w/w)

0 phr Cl30B

2 phr Cl30B

8

The ABS/PC blends exhibit higher MFI than that of PC.

ABS exhibits lower MFI than PP and ABS/PP blends presents melt behavior closer to that of PP.

Blending of polymers is the key for the improvement of their processability.

Tensile test

The tensile strength of ABS is increased by the addition of PC, whereas it is decreased significantly by the addition of PP.

In ABS/PC blends, the tensile strength seems to follow the rule of mixture. In ABS/PP blends, the tensile strength is closer to that of pure PP. The incorporation of organoclay in ABS/PC blends seems to cause a slight increase in the

tensile strength.

In ABS/PC blends, a synergic action between the two polymers is observed for Young’s modulus.

In ABS/PP blends, the Young’s modulus is decreased as the PP concentration is increased. The addition of organoclay significantly improves the Young’s modulus of the examined

blends. The enhancement of stiffness is interpreted by the higher modulus of organically modified

clay and by the low deformability of polymeric chains penetrating the silicate galleries.

100/0 70/30 50/50 30/70 0/10025

30

35

45

50

55

60

65

70

Ten

sile

str

en

gth

(M

Pa)

(w/w)

0 phr Cl30B/ABS/PC

2 phr Cl30B/ABS/PC

0 phr Cl30B/ABS/PP

2 phr Cl30B/ABS/PP

100/0 70/30 50/50 30/70 0/1001250

1500

1750

2000

2250

2500

2750

Yo

un

g's

mo

du

lus

(MP

a)

(w/w)

0 phr Cl30B/ABS/PC

2 phr Cl30B/ABS/PC

0 phr Cl30B/ABS/PP

2 phr Cl30B/ABS/PP

9

+ 4-13.5%: ABS/PC

+ 14-23.5%: ABS/PP

Dynamic Mechanical Analysis (DMA)

-100 -50 0 50 100 150 2000.00E+000

5.00E+008

1.00E+009

1.50E+009

2.00E+009

2.50E+009

3.00E+009

Sto

rag

e m

od

ulu

s (P

a)

T (oC)

100/0 ABS/PC

70/30 ABS/PC

50/50 ABS/PC

30/70 ABS/PC

0/100 ABS/PC

-120 -90 -60 -30 0 30 60 90 120 1500.00E+000

5.00E+008

1.00E+009

1.50E+009

2.00E+009

Sto

ra

ge m

od

ulu

s (P

a)

T (o

C)

100/0 ABS/PP

70/30 ABS/PP

50/50 ABS/PP

30/70 ABS/PP

0/100 ABS/PP

-120 -90 -60 -30 0 30 60 90 120 1500.00E+000

5.00E+008

1.00E+009

1.50E+009

2.00E+009

2.50E+009

3.00E+009

Sto

ra

ge m

od

ulu

s (M

Pa

)

T (o

C)

30/70 ABS/PC

2 phr Cl30B/30/70 ABS/PC

30/70 ABS/PP

2 phr Cl30B/30/70 ABS/PP

A synergistic effect is observed for ABS/PC blends and the greatest value is recorded for 50/50 w/w composition.

Below 10 oC, the ABS/PP blends present higher storage modulus than that of neat ABS and lower than or equal to that of neat PP. On the contrary, over 10 oC, the Gʹ of ABS/PP blends is higher than that of neat PP and lower than that of neat ABS.

The ABS/PC blends present higher storage modulus than that of ABS/PP blends.

The incorporation of organoclay leads to an impressive increase of storage modulus, in comparison with this corresponding to unreinforced blends.

10

PC

ABS blends

25 oC

ABS

PP

Thermogravimetric Analysis (TGA)

250 300 350 400 450 500 550 600 650-0.025

-0.020

-0.015

-0.010

-0.005

0.000

Deriv

ati

ve o

f w

eig

ht

ch

an

ge (

%/o

C)

T (oC)

100/0 ABS/PC

70/30 ABS/PC

50/50 ABS/PC

30/70 ABS/PC

0/100 ABS/PC

300 350 400 450 500 550 600-0.020

-0.015

-0.010

-0.005

0.000

Deriv

ati

ve o

f w

eig

ht

ch

an

ge (

%/o

C)

T (oC)

50/50 ABS/PC

2 phr Cl30B/50/50 ABS/PC

30/70 ABS/PC

2 phr Cl30B/30/70 ABS/PC

The thermal stability increases with the following order: ABS<PP<PC.

In ABS/PC blends, the thermal degradation mechanism takes place in one stage, whereas in ABS/PP blends it involves two stages.

The incorporation of clay platelets in PC-rich ABS/PC blends turns the thermal degradation mechanism to a two stages process and leads to higher values of char residue.

The OMMT seems to inhibit thermal degradation of the PC phase, which might be due to the creation of new paths of the degradation reaction and to the formation of a protective layer of nanoclay at the ABS/PC interface.

300 325 350 375 400 425 450 475 500

-0.025

-0.020

-0.015

-0.010

-0.005

0.000

Deriv

ati

ve o

f w

eig

ht

ch

an

ge (

%/o

C)

T (oC)

100/0 ABS/PP

70/30 ABS/PP

50/50 ABS/PP

30/70 ABS/PP

0/100 ABS/PP

1st stage 2nd stage

11

Gross Calorific Value (GCV)

ABS/PC ABS/PP8000

8200

8400

8600

9800

10000

10200

10400

GC

V (

cal/

/g o

rgan

ic m

ate

ria

l)

50/50 w/w

0 phr Cl30B

2 phr Cl30B

100/0 70/30 50/50 30/707500

7750

8000

8250

8500

9000

9250

9500

9750

10000

10250

10500G

CV

(cal/

g o

rgan

ic m

ate

ria

l)

ABS/PC (w/w)

0 phr Cl30B

2 phr Cl30B

As the PC content in ABS/PC blends increases, a reduction of GCV is observed, due to the poor burning characteristics of PC as compared with ABS.

The incorporation of OMMT to ABS/PC or ABS/PP blends does not have a significant effect.

Emissions from hazardous substances in WEEE (heavy metals, halogens, organic components like brominated and chlorinated flame retardants) complicates the technical aspects of energy recovery.

The GCV increases with the following order: PC < ABS < PP.

12

Conclusions

The addition of PC in ABS matrix improves its thermomechanical properties, whereas the addition of ABS in PC matrix makes feasible its processing at lower temperatures.

The addition of PP in ABS matrix increases its thermal stability, whereas the addition of ABS in PP matrix improves its mechanical behavior.

The incorporation of OMMT to ABS/PC or ABS/PP blends leads to an increase of their melt viscosity, improves significantly the Young’s modulus and the storage modulus and protects the PC phase during the thermal decomposition of PC-rich, ABS/PC blends.

The blending of polymers used in WEEE is an appropriate procedure for their common management, which eliminates the time consuming and costly phase of sorting.

The incorporation of organoclay to polymer blends is a low-cost and environmentally friendly alternative technique for the upgrading of their performance during their mechanical recycling.

13

Future Research

14

Thorough investigation capability of Cloisite 30B to improved compatibility and performance of ABS/PC and ABS/PP blends.

Extension of the study to other polymeric blends with various components (e.g. PC/SAN).

Upgrading of the examined plastic blends by the incorporation of the appropriate amount of additives (e.g. carbon nanotubes, graphene) as advanced technology reinforcing fillers.

National Technical University of Athens

School of Chemical Engineering

Polymer Technology Lab.

RECYCLING AND REUSE OF PLASTICS CONTAINED IN

WASTE FROM ELECTRICAL AND ELECTRONIC

EQUIPMENT

Μ.Ι.Triantou*, P.A.Tarantili, A.G.Andreopoulos

2nd International Conference on Sustainable Solid Waste Management, Athens, Greece, 12-14 June, 2014

Thank you very much

for your attention

*e-mail: mtriantou@teemail.gr

16

Temperature at six zones of extruder (oC)

1st 2nd 3rd 4th 5th Die

(100/0 w/w) ABS/PC 210 200 200 195 195 190

(100/0 w/w) ABS/PC* 190 195 195 200 200 205

(70/30 w/w) ABS/PC 230 215 215 210 210 205

(50/50 w/w) ABS/PC 240 235 235 230 230 225

(30/70 w/w) ABS/PC 260 255 255 250 250 245

PC 290 280 275 270 265 260

Temperature at six zones of extruder (oC)

1η 2η 3η 4η 5η Die

0/100 ABS/PP 180 180 185 185 190 190

30/70 ABS/PP 190 190 195 195 200 200

50/50 ABS/PP 190 190 195 195 200 200

70/30 ABS/PP 190 190 195 195 200 200

100/0 ABS/PP 190 195 195 200 200 205

Screw speed:200 rpm

ABS is composed of :44% acrylonitrile42% styrene14% butadiene

17

50/50 ABS/PC nanocomposite

According to SEM this nanocompositeconsists of a continuous ABS phase and a dispersed PC phase.

Clay tactoids are arranged mainly on the ABS/PC interphase and in the ABS phase

It is possible the formation of a physical crosslinking network structure composed of clay particles and polymeric chains which limitates the chains’ motion and protects them during the thermal degradation.

The heat barrier effect could also provide superheated conditions inside the polymer melt leading to extensive random scission of polymer chain and evolution of numerous chemical species which, trapped between clay layers, have more opportunity to undergo secondary reactions. As a result, some degradation pathways could be promoted leading to enhanced charring.

The clay may permit radical recombination reactions, exerting thus a stabilization effect in the ABS/PC/layered silicate nanocomposite.

The dispersion of organoclay layers leads to the formation of a tortuous path which inhibits the passage of volatile degradation products during the initiation of thermal degradation (labyrinth effect).