Transcript marco_paoli_humboldt_2009.ppt

LOW ENVIRONMENTAL IMPACT PLASTICS
Prof.Marco-Aurelio De Paoli
Universidade Estadual de Campinas (UNICAMP) - Brasil
2009
Post-doctoral work at MPI für Strahlenchemie, RFA, 1975 – 1977.
Alexander von Humboldt Stiftung
Introduction
Aims of our research:
• Develop thermoplastic composites with adequate
mechanical properties, reduced environmental impact
and good cost/benefit ratio; use of renewable
resources.
•To replace short glass fibers in reinforced
thermoplastics processed by injection molding; weight
and environmental impact reduction.
Introduction
“They (automobiles) will be
lighter and much of them will
be built of plastics developed
from farm products”.
Henry Ford, from an article written by James
Schweinehart published in The Detroit News of
July, 30rd, 1942.
Car parts made with natural fibers composite
Introduction
Vegetal fibers can be used in substitution to fiber glass due to
the following advantages:
•Produced from renewable resources.
•Less abrasive to the processing equipments.
•Lower density, producing lighter composites,
•Better thermal and acoustic insulation,
•Better surface finish in injection molded parts,
Introduction
Vegetal fibers also present some challenges.
•Vegetal fibers decompose thermally above 220 oC.
•Like with fiberglass, composites cannot be mechanically recycled. They
can be recycled only by pyrolysis (however, with carbon credits),
•Vegetal fibers reinforced thermoplastics show higher flammability, thus,
the use of a flame retardant is necessary.
•Achieve a competitive cost in relation to synthetic fibers.
Introduction
Why use Curauá fibers and not the market available vegetal fibers ?
stress., E e b specific for Curauá fibers
Fiber
dens.
FC
1,10
força máx /  (MPa /g.cm-3)
636-1000
E /  (GPa cm3/g)
b /  (% cm3/g)
36 ± 10
3±1
Specific density, stress, E and b for same reinforcing fibers*
Density g/cm3
/
MPa /g.cm-3
E/
GPa cm3/g
b / 
% cm3/g
cotton
1,5-1,6
191-398
3,4-7,9
4,7-5,0
Jute
1,3
302-595
20,4
1,2-1,4
Linho
1,5
230-790
18,4
1,8-2,1
Ramie
1,5
270-625
41-85
2,4-2,5
Sisal
1,5
340-416
6,3-14,7
1,3-1,7
glass (E)*
2,5
800-1400
28
1,0
glass (S)**
2,5
1800
34,4
1,1
Aramid
1,4
2140-2240
45-48
2,4-2,6
Carbon
1,4
2860
164-171
1,0-1,3
fiber
* Electric insulation, ** militar applications.
*- from: A. K. Bledzki; J. Gassan. Composites reinforced with cellulose based fibres. Progres in Polymer Science 24 (1999) 221-274.
Materials used
HDPE, Braskem, MFI = 7 g/10 min.
PP, Braskem, MFI = 10 g/10 min.
Curauá fibers, dryed and milled in a three knives
rotary mill, Rone.
Processing equipment
Co-rotating interpenetrating twin-screw extruder, Werner-
Pfleiderer ZSK-26, L = 1056, D = 24 mm, L/D = 44 (Fapesp
2004/15084-6), SRS 250 – 500 rpm, side feeder 200 – 465 rpm.
Main feeder
side feeder
Injection molding Arburg All Rounder M-250
degasing
Processing equipment
Experimental: processing parameters
HDPE matrix
SRS* (rpm)
Mass temperature
(°C)**
Pressure
(bar)
Torque
(%)
Output
(kg/h)
SME***
(Wh/kg)
250/200
136-160
4-19
33-40
1.9
1.1
300/250
143-164
4-22
34-38
2.2
1.1
350/300
140-168
6-16
30-42
2.4
1.2
400/350
151-172
5-23
28-41
3.1
1.0
500/450
145-178
9-14
32-37
3.5
1.1
PP matrix
250/215
171-195
7-16
31-41
2.5
0,8
300/265
177-195
8-16
30-37
2.6
0,9
350/315
177-199
7-16
29-34
2.6
1,0
400/365
175-204
10-16
27-34
2.9
1,0
500/465
178-202
10-12
29-37
3.6
1,0
*Main screws/side feeder screws
** polymer temperature near the dye
*** Specific Mechanical Energy
HDPE matrix: effect of SR on fiber geometrical parameters
1.0
CFD
0.8
0.6
0.4
0.2
0
20
40
60
80
100
120
Aspect Ratio
Legend: pristine fiber () and composites processed at () 250, () 300, () 350 (), 400 and () 500 rpm
Screw rotation (rpm)
ARn
ARw
ARw/ARn
250
18
35
2
300
16
34
2
350
15
28
2
400
12
20
2
500
7
10
1
Above 350 rpm, aspect ratio decreases
HDPE-Fibrillation effect: MEV
50 μm
100 μm
6 μm
Matriz HDPE: mechanical properties
55
45
14% tensile
7% flexural
3.5
3.0
E / GPa
máx. / MPa
50
4.0
40
35
2.5
2.0
1.5
30
1.0
25
0.5
250/200 300/250 350/300 400/350 500/450
screw rotation / side-feeder
26% tensile
Flexural n.v.
250/200 300/250 350/300 400/350 500/450
screw rotation/side-feeder
6
5
50%
The yield stress and Young’s Modulus show a
decreasing tendency, in accordance with the
decrease in the fiber aspect ratio.
/%
4
3
The elongation at break increases due to the
decline in the reinforcement effect.
2
1
250/200 300/250 350/300 400/350 500/450
screw rotation / side-feeder
HDPE
Tensile mechanical tests - ASTM D-638
Formulação
em wt %
máx./
(MPa.g/cm3)
máx. (MPa)
E (MPa)/
(MPa.g/cm3)
E (MPa)
 (%)/
 (%)
HDPE
17.8 ± 0.1
1358 ± 152
< 100
HDPE/20%FC
28.4 ± 0.2
28.1 ± 0.2
2501 ± 447
2471 ± 447
3.7 ± 0.1
3.7 ± 0.1
HDPE/20%FC/
2%PEAM
30.7 ± 0.3
30.3 ± 0.3
2763 ± 294
2730 ± 294
3.2 ± 0.5
3.2 ± 0.5
HDPE/30%FV*
42 - 51
52 - 63
3952 - 5080
4900 - 6300
1.2 - 2.0
1.5 - 2.5
dCFC = 0.988 ± 0.04 g/ cm3 (15,7 % em volume)
dCFV = 1.2 - 1.28 g/ cm3 ( 1,27 g/cm3 com 15 % em volume)
*PE 30 % GF – Polyethylene 30 % Glass fiber ®, Omnexus, United States, 2007.
HDPE
Flexural mechanical tests ASTM D-790
Formulação
em wt %
máx./
(MPa.g/cm3)
máx. (MPa)
E (MPa)/
(MPa.g/cm3)
E (MPa)
HDPE
20.9 ± 0.5
888 ± 43
HDPE/20%FC
37.5 ± 0.3
37.1 ± 0.3
1609 ± 98
1590 ± 98
HDPE/20%FC/
2%PEAM
41.4 ± 0.3
40.9 ± 0.3
1983 ± 129
1959 ± 129
HDPE/30%FV
*
42 - 51
52 - 63
3952 - 4516
4900 - 5600
dCFC = 0.988 ± 0.04 g/ cm3 (15,7 % em volume)
dCFV = 1.2 - 1.28 g/ cm3 ( 1,27 g/cm3 com 15 % em volume)
*PE 30 % GF – Polyethylene 30 % Glass fiber ®, Omnexus, United States, 2007
HDPE
Impact resistence ASTM D-256
Formulação
em wt %
Resistência
ao Impacto
Izod (J.g/cm3)
(J/m)
Resistencia
ao Impacto
Charpy
(kJ/m2)
HDPE
82.3 ± 6.4
3.5 ± 0.1
HDPE/20%FC
62.8 ± 2.9
62.0 ± 2.9
3.5 ± 0.4
HDPE/20%FC/
2%PEAM
66.0 ± 3.9
65.2 ± 3.9
3.4 ± 0.2
HDPE/30%FV
*
48 - 64
60-80
-
dCFC = 0.988 ± 0.04 g/ cm3 (15,7 % em volume)
dCFV = 1.2 - 1.28 g/ cm3 ( 1,27 g/cm3 com 15 % em volume)
*PE 30 % GF – Polyethylene 30 % Glass fiber ®, Omnexus, United States, 2007
PP matrix: effect of SR on fiber geometrical parameters
1.0
CDF
0.8
0.6
0.4
0.2
0.0
0
20
40
60
80
100
120
Aspect ratio
Legend: pristine fiber () and composites processed at () 250, () 300, () 350 (), 400 and () 500 rpm
Screw rotation (rpm)
ARn
ARw
ARw/ARn
250
15
27
2
300
15
20
1
350
13
33
3
400
11
27
3
500
9
23
3
Changes in aspect ratio with screw rotation
PP-Fibrillation effect: MEV
PP matrix: mechanical properties
60
50
4.5
4.0
5% tensile
flexural n.v.
3.5
45
E / GPa
máx. / MPa
55
5.0
12.5% tensile
flexural n.v.
40
35
3.0
2.5
2.0
1.5
30
1.0
25
0.5
250/215 300/265 350/315 400/365 500/465
250/215 300/265 350/315 400/365 500/465
screw rotation / side-feeder
screw rotation / side-feeder
7
6
32%
/%
5
Tensile yield stress and Young Modulus show
a decreasing tendency, in accordance with the
variation in the fiber aspect ratio.
4
3
The elongation at break increases due to the
decline in the reinforcement effect.
2
1
250/215 300/265 350/315 400/365 500/465
screw rotation / side-feeder
PP
Mechanical tensile tests, ASTM D-638
Formulação
em wt %
σmáx./d (MPa/g cm
-3)
σ máx. (MPa)
E (MPa)/d
(GPa.g/cm3)
E (MPa)
 (%)/d
e (%)
PP
27,2 ± 0,5
1736 ± 112
> 300
PP/20%FC
32,3 ± 0,2
31,4 ± 0,5
2870 ± 254
2790 ± 254
1,9 ± 0,2
1,8 ± 0,2
PP/20%FC/2%PPAM
39 ± 0,2
38 ± 0,2
3393 ± 357
3298 ± 357
2,2 ± 0,3
2,1 ± 0,3
PP/20%FV*
43
45
3810
4000**
4,8
5
dCFC = 0, 972 ± 0, 010 g/ cm3 (15 % em volume)
dCFV = 1,05 g/ cm3 (1,14 g/cm3 com 8 % em volume)
* PP com 20 wt% de FV – Petrotene PH304, Petropol Polímeros
** Polypropylene/ 20 % Glass fibre ®, Omnexus, United States, 2007
PP
Flexural mechanical tests, ASTM D-790
Formulação
em wt %
máx./
(MPa/g/cm3)
máx. (MPa)
E (MPa)/
(MPa/g/cm3)
E (MPa)
PP
37,1 ± 1,4
1046 ± 59
PP/20%FC
51 ± 1
50 ± 1
2187 ± 100
2126 ± 100
PP/20%FC/2%PPAM
58 ± 1
56 ± 1
1913 ± 214
1859 ± 214
PP/20%FV*
76
80
3000
3000
dCFC = 0, 972 ± 0, 010 g/ cm3 (15 % em volume)
dCFV = 1,05 g/ cm3 (1,14 g/cm3 com 8 % em volume)
* PP com 20 wt% de FV – Petrotene PH304, Petropol Polímeros
PP
Impact resistence tests, ASTM D-256
Formulação
em wt %
Resistência
ao Impacto
Izod (J/g/cm3)
(J/m)
Resistência
ao Impacto
Charpy
(kJ/m2)
PP
17,3 ± 4,43
1,6 ± 0,2
PP/20%FC
28 ± 9
27 ± 9
3,3 ± 0,6
PP/20%FC/2%PPAM
29 ± 3
28 ± 3
2,6± 0,3
PP/20%FV*
52
55
-
dCFC = 0, 972 ± 0, 010 g/ cm3 (15 % em volume)
dCFV = 1,05 g/ cm3 (1,14 g/cm3 com 8 % em volume)
* PP com 20 wt% de FV – Petrotene PH304, Petropol Polímeros
Car parts made with Nylon-6/curauá fibers composite
Developed under contract with Sabic Innovative Plastics
Car parts made with Nylon-6/curauá fibers composite
Developed under contract with Sabic Innovative Plastics
CONCLUSIONS
• Aspect ratio of the fibers in the injection molded samples is
affected by the processing conditions in the extruder.
• For both polymers, the mechanical properties are affected
by the fiber aspect ratio variation.
•
HDPE is more affected than PP by the processing
conditions.
• Final mechanical properties depend on the correct choice
of processing conditions.
Research group
•
•
•
•
•
•
•
•
•
•
MSc, Bárbara Mano,
MSc, Joyce Araújo,
Vanessa S de Oliveira
Prof. Dr. Márcia AS Spinacé
Léa Garcia Janeiro
Filippe Bernardino
Thais Grossi
MSc, Paulo Santos (SABIC)
Karen Fermoselli (SABIC/Unicamp)
Prof. Dr. Walter R Waldman (UENF)
ACKNOWLEDGEMENTS
Procs.04/15084-6, 06/58342-0, 06/58343-7,
08/06503-6 e 08/06506-8.