This presentation was an input Dr. Bernard Effah, from Kumasi Technical University – Ghana, gave as an input during the BioHome Summer School in University of Hamburg & Thünen Insitute in Hamburg (31 May - 14 June 2019)

1. Affordable and sustainable building materials
from lesser used lignocellulosic and recycled
plastics for Ghana
By
Bernard Effah (PhD)
Kumasi Technical University – Ghana
Biohome Summer School, 2019

2. Outline
• Background
• WPC
• On‐going works
• Outlook
• Conclusion
• Acknowledgement
2

3. Background
Build Africa:
Bio‐based and Recycling Resources
3

4. The state of housing in Africa
Kenya (pop. 44.4m)
Housing backlog of 2m units;
estimated annual deficit of
200K units
Cameroon (pop. 25m)
Housing backlog of over 700k
units
Angola (pop. 21.5m)
Housing deficit of over 1.9m; estimated
annual shortage of 100K
Ivory Coast (pop. 20.3m)
Housing backlog of over 700k
units
Ethiopia (pop. 94.1m)
Estimated deficit of 1mn units;
100k annual shortage
Nigeria (pop. 173.6m)
Housing backlog of 17m; annual
shortage of 700k units
South Africa (pop. 53m)
Housing deficit of 2‐3m units; an estimated 1.5m
households live in slums
Morocco (pop. 33.01m)
Housing deficit of 800k units
Uganda (pop. 37.6m)
Estimated annual housing deficit
of 233k units.
Source: Faye (2015); African housing finance
year book (2015)
Tanzania (pop. 51.8m)
Housing backlog of 3m units;
estimated annual deficit of
200K units
Ghana (pop. 26.4m)
Housing backlog of 1.7m; annual
shortage of 100k units

5. Construction costs in Africa
(GWS Online GH, 2019)
5

6. Informal settlements
6
Many slums Tenure insecurity

7. Reasons
7
70% Importation of building materials
High cost of building materials
2 bedroom houses cost
between US $35,000
and 40,000 (affordable)

8. The solution
• Use of local and alternative materials in the building
industry
8

9. Making a case for WPC adoption
9

10. Wood Plastic Composites
The term “wood‐plastic composites” refers to any composites that
contain wood (of any form) and either thermoset or thermoplastic
polymers (Caulfield et al. 2005).
Wood–plastic composite (commonly abbreviated as WPC) is a
composite material lumber or timber made of recycled plastic and
wood wastes (Kim & Pal, 2010)
Wood‐plastic composites (WPCs) are composite materials made of
wood fiber/wood flour and thermoplastic(s) (includes Low Density
Polyethylene (LDPE), High Density Polyethylene, (HDPE),
Polypropylene (PP), and Poly Vinyl Chloride (PVC) etc.).
10

11. WPC Facts
• Composite materials made of wood waste and
recycled thermoplastics
• No additional wood resources depleted
• Used just like wood but has the best features of
wood and plastics
• Wood and plastic each bring their own strengths to a
composite material
• Utilization of low‐grade woody biomass
• A better "value added"
11

12. Components of WPCs
1
2
12

13. WPC Application
It is used in numerous applications, such as
• outdoor deck floors
• Railings
• Fences
• landscaping timbers
• cladding and siding, park
• benches,
• molding and trim
• window and door frames
• indoor furniture
13

14. Decking
Wall Cladding
Fencing Packaging
Railing
Louvers
Garden Benches Pergola
Automotive
WPC Application
14

15. Why choose WPC
15

16. Why choose WPC
Low moisture absorption
Safe from cracks
Resistant to rot
16

17. Processing of WPC
17

18. 18

19. WPC challenges
• Fundamentally wood and plastic are like oil and
water, and do not mix well.
• Wood is hydrophilic – it absorbs water; and plastic is
hydrophobic, repels water.
• A "compatibilizer,“ typically a polymer that bridges
the interface between the wood and plastic in the
products, improves stress transfer and increases their
strength and stiffness.
19

20. Fiber modification
(Ashori, 2008)
20

21. (Stokke et al. 2014)
21

22. Properties
22

23. Composition and suitability of
invasive species for Wood‐Polymer
Composites
Bernard Effah, Marco De Angelis, Goran Schmidt,
Andreas Krause and Martina Meincken
23

24. Background and Justification
• Plastic bags of all sizes and colour dot the country‘s
landscape due to the problems of misuse and overuse
and littering in the country.
24

25. • Clogged drains lead to flooding with
resulting loss of lives, destruction of
property and reduced productivity.
• Creation of breeding grounds for
mosquitos, rats and other rodents.
• Agricultural residues
• Invasive plants
25

26. The triple‐win
Aim of the project
• The three Es; environmental, ecological and
economical.
• Environmental: Reduce Waste – reduce dump and
landfill (less Methane emission)
• Ecological: Reduce CO2 emission by usage of
renewable resource.
• Economical: Material and job creation through
labour‐intensive collection, sorting and recycling of
lignocellulosics and plastics
26

27. Objective
• Investigate the suitability of using invasive tree
species flour and recycled plastics for the production
of wood plastic composites (WPCs).
27

28. Experimental: Materials
Wood filler
• Leucaena leucocephala samples
• (two compartments; 1. Wood 2. Wood with bark).
• Grounded to fine flour (1 mm)
Thermoplastic polymer
Recycled HDPE
HDPE
Coupling agent: MAPE
28

29. Formulation
1 HDPE
2 RHDPE
3 IM HDPE C320 MAPE
4 IM HDPE C320
5 IM RHDPE C320 MAPE
6 IM RHDPE C320
7 CM RHDPE C320 MAPE
8 CM RHDPE C320
9 CM HDPE C320 MAPE
10 CM HDPE C320
Groupings
Formulation
1 HDPE
2 RHDPE
11 RHDPE W+B MAPE
12 RHDPE W+B
13 HDPE W+B MAPE
14 HDPE W+B
15 RHDPE WOOD MAPE
16 RHDPE WOOD
17 HDPE WOOD MAPE
18 HDPE WOOD
Group 1 Group 2
Variables
CA
Process
CA
Species
29

30. Group 1: Tensile strength
HDPE
RHDPE
IM
HDPE C320 MAPE
IM
HDPE
C320
IM
RHDPE C320 MAPE
IM
IM
RHDPE C320
CM
RHDPE C320 MAPE
CM
RHDPE
C320
CM
HDPE C320 MAPE
CM
HDPE
C320
10
15
20
25
30 TENSILE STRENGTH
TENSILESTRENGTH(Fmax.MPa)
30

31. Tensile MoE
HDPE
RHDPE
IM
HDPE
C320 MAPE
IM
HDPE
C320
IM
RHDPE
C320 MAPE
IM
IM
RHDPE
C320
CM
RHDPE
C320 MAPE
CM
RHDPE
C320
CM
HDPE
C320 MAPE
CM
HDPE
C320
0
1
2
3
4
5
TENSILE MoE
TENSILEMoE(GPa)
31

32. Elongation at break
HDPE
RHDPE
IM
HDPE
C320 MAPE
IM
HDPE
C320
IM
RHDPE C320 MAPE
IM
IM
RHDPE
C320
CM
RHDPE C320 MAPE
CM
RHDPE C320
CM
HDPE C320 MAPE
CM
HDPE C320
0
2
4
6
8
10
12
14
16
ELONGATION AT BREAK
ELONGATIONATBREAK(%)
32

33. Impact
HDPE
RHDPE
IM
HDPE C320 MAPE
IM
HDPE C320
IM
RHDPE C320 MAPE
IM
IM
RHDPE C320
CM
RHDPE C320 MAPE
CM
RHDPE C320
CM
HDPE C320 MAPE
CM
HDPE C320
-20
0
20
40
60
80
100
120
140
160
IMPACT STRENGTH
IMPACTSTRENGTH(kJ/m
2
)
33

34. Group 2: Tensile strength
HDPE
RHDPE
RHDPE W+B MAPE
RHDPE W+B
HDPE W+B MAPE
HDPE W+B
RHDPE WOOD
MAPE
RHDPE WOOD
HDPE WOOD
MAPE
HDPE WOOD
8
10
12
14
16
18
20
22
24
26
TENSILE STRENGTHTENSILESTRENGTH(Fmax.MPa)
34

35. Tensile MoE
HDPE
RHDPE
RHDPE
W
+B
MAPE
RHDPE
W
+B
HDPE
W
+B
MAPE
HDPE
W
+B
RHDPE
W
OOD
MAPE
RHDPE
W
OOD
HDPE
W
OOD
MAPE
HDPE
W
OOD
0.5
1.0
1.5
2.0
2.5
3.0
3.5
TENSILE MoE
TENSILEMoE(GPa)
35

36. Elongation at break
HDPE
RHDPE
RHDPE W+B MAPE
RHDPE W+B
HDPE W+B MAPE
HDPE W+B
RHDPE WOOD
MAPE
RHDPE WOOD
HDPE WOOD
MAPE
HDPE WOOD
0
2
4
6
8
10
12
14
16
ELONGATION AT BREAK
ELONGATIONATBREAK(%)
36

37. Impact
HDPE
RHDPE
RHDPE W+B MAPE
RHDPE W+B
HDPE W+B MAPE
HDPE W+B
RHDPE WOOD
MAPE
RHDPE WOOD
HDPE WOOD
MAPE
HDPE WOOD
-20
0
20
40
60
80
100
120
140
160
IMPACT STRENGTH
IMPACTSTRENGTH(kJ/m
2
)
37

38. Effect of species and compatibilizers
on the weatherability of Wood‐
Polymer Composites
Marco De Angelis, Bernard Effah, Goran Schmidt,
Andreas Krause and Martina Meincken
38

39. Aging and release of micro plastics
39

40. Objective
• Examine the durability performance (long‐term
resistance to weathering) of WPCs for in and outdoor
applications.
40

41. Results and observations
41

42. ‐0.6
‐0.5
‐0.4
‐0.3
‐0.2
‐0.1
0 0
168
336
504
672
840
1008
1176
1344
1512
1680
1848
2016
Colour change (ΔL*)
Accelerated weathering (h)
Inj. molding
IM RHDPE
C320
IM RHDPE
C320 MAPE
IM HDPE C320
IM HDPE C320
MAPE
‐0.7
‐0.6
‐0.5
‐0.4
‐0.3
‐0.2
‐0.1
0
0
168
336
504
672
840
1008
1176
1344
1512
1680
1848
2016
Colour change (ΔL*)
Accelerated weathering (h)
WOOD
CM HDPE WOOD
CM HDPE WOOD
MAPE
CM RHDPE Wood
CM RHDPE WOOD
MAPE
‐0.6
‐0.5
‐0.4
‐0.3
‐0.2
‐0.1
0
0
168
336
504
672
840
1008
1176
1344
1512
1680
1848
2016
Colour change (ΔL*)
Accelerated weathering (h)
C320
CM RHDPE C320
CM RHDPE C320
MAPE
CM HDPE C320
CM HDPE C320 MAPE
‐0.7
‐0.6
‐0.5
‐0.4
‐0.3
‐0.2
‐0.1
0
0
168
336
504
672
840
1008
1176
1344
1512
1680
1848
2016
Colour change (ΔL*)
Accelerated weathering (h)
W+B
CM RHDPE W+B
CM RHDPE W+B
MAPE
CM HDPE W+B
CM HDPE W+B MAPE

43. 0.000
0.005
0.010
0.015
0.020
0.025
0.030
0
168
336
504
672
840
1008
1176
1344
1512
1680
1848
2016
Colour change (Δa*)
Accelerated weathering (h)
WOOD
CM HDPE WOOD
CM HDPE WOOD
MAPE
CM RHDPE WOOD
CM RHDPE WOOD
MAPE
0.000
0.005
0.010
0.015
0.020
0.025
0.030
0 336 672 1008 1344 1680 2016
Colour change (Δa*)
Accelerated weathering (h)
C320
CM RHDPE C320
CM RHDPE C320
MAPE
CM HDPE C320
CM HDPE C320 MAPE
‐0.005
0.000
0.005
0.010
0.015
0.020
0.025
0 336 672 1008 1344 1680 2016
Colour change (Δa*)
Accelerated weathering (h)
Inj. molding
IM RHDPE C320
IM RHDPE C320 MAPE
IM HDPE C320
IM HDPE C320 MAPE
0.000
0.002
0.004
0.006
0.008
0.010
0.012
0.014
0.016
0.018
0.020
0
168
336
504
672
840
1008
1176
1344
1512
1680
1848
2016
Colour change (Δa*)
Accelerated weathering (h)
W+B
CM RHDPE W+B
CM RHDPE W+B MAPE
CM HDPE W+B
CM HDPE W+B MAPE

44. Results and observations
Polymer degradation
• WPCs exposed to weathering by solar radiation (ultraviolet
light), oxidation, and rain water experienced colour
change.
• Possible loss of mechanical properties.
• The colour change may affects the aesthetic quality,
whereas the mechanical loss may affects the performance.
• Weathering to some extent destroyed the surface of the
WPC by surface oxidation, matrix crystallinity changes, and
interfacial degradation, which can lead to other negative
effects.
44

45. Conclusion
• There is a growing demand for new sustainable
construction materials capable to substitute conventional
materials economically and ecologically.
• Developing WPCs from lesser used lignocellulosic and
recycled plastics are a convenient source of raw materials
that can form durable products, clean the environment,
reduce destruction of forests and avoid landfill.
• Improvements in weather ability will open more
applications.
• Ecomenia (ecological + profitable)
45

46. Outlook
How do we get this technology
transferred to Africa ?
46

47. Acknowledgement
Institute of Wood Science
Thünen Institute of Wood Research
47

48. Thank You
48