Mechanical and Rheological behavior of basalt and hemp ...

Mechanical and Rheological behavior of basalt and

hemp fiber reinforced thermoplastic composites

Bharath K. Nagaraja, Vikram Yadama, and Lloyd V. Smith

Composite Material and Engineering Center

Washington State University, Pullman, WA

Composite Materials and Engineering Center

Automotive Composites Conference & Exhibition (ACCE)Novi, MichiganSeptember 4-6,2019


Introduction

• Natural fibers offer several advantages, such as being renewable

materials and weight, for use in bio-products and bio-composites

• However, they have an affinity for water, are more susceptible to

fire, have greater variation, and interact poorly

• This study proposes potential solutions to overcome some of these

shortcomings to produce bio-based composites for automotive

applications

• Automotive industry is actively exploring synthetic materials, such

as glass fiber and carbon fiber reinforced composites, but there is

also a desire to use more materials that are renewable and can be

recycled

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Long-term goal of the project

• To investigate the influence of Natural fiber (Hemp Fiber)

on Basalt fiber/PP/MAPP composites

• Using mixture model design to obtain different

formulations

• To evaluate tensile strength, stiffness, toughness, flexural,

impact, dimension stability and to study the morphology

• Also, study the fire and sound properties of these

composites

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Objectives of this talk

The objective of the work are to:

➢ Investigate the influence of formulation on the performance

of injection molded basalt fiber/PP composite material

➢ Investigate the effect of MAPP on the basalt fiber/PP

composites

➢ Evaluate the influence of fiber content on fiber/thermoplastic

resin for tensile strength and modulus

➢ Study the rheological behavior of hybrid basalt/hemp fiber

reinforced polypropylene composites

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Chemical Composition of Basalt

Source: Compressive Stress-Strain Behavior of HSFRC Reinforced with Basalt Fibers, Journal of Materials in Civil Engineering 2015, 28(4)

✓ Service temperature range -452° F to

1,200° F (-269° C to +650° C)

✓ Density - 2.6 gm/cc

✓ Excellent shock resistance - good for

ballistic applications

✓ Higher oxidation & radiation resistance

✓ Good fatigue and corrosion resistance

✓ Better chemical resistance than E-glass

✓ Density – 0.8 gm/cc

✓ Cost-effective

✓ Reduces molding time

✓ Weight reduction in finished part

✓ Can be customized to meet a variety

of specifications and different

manufacturing systems

Chemical composition and properties of

Basalt fiber and Hemp fiber

Major Chemical

Composition of Basalt FiberPercentages

SiO2 51.6-59.3

Al2O3 14.6-18.3

CaO 5.9-9.4

MgO 3.0-5.3

Major Chemical

Composition of Hemp FiberPercentages

Cellulose 77.5

Hemi-cellulose 10

Lignin 6.8

Pectin 2.9

Fat and Wax 0.9

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Polypropylene from RheTech

➢ Density: 0.8965 g/cm3

➢ Tensile Strength at yield, MPa: 22.6

➢ Notched charpy at 23°C: 11 KJ/m2

➢ Melting Point: 162°C (324°F)

➢ Heat deflection temperature at 0.45 Mpa: 118 °C

➢ Melt flow rate, 230 °C/2160 g: 26 dg/min (avg)

Thermoplastic resins Properties

Sources: Material specification data, RheTech

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Basalt Fiber : 0 < X1 < 35

MAPP : 0 < X2 < 5

Polypropylene : 65 < X3 < 100

Mixture design for composites

Table: Design of Experiments

Condition : X1 + X2 + X3 = 100

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Component 1 Component 2 Component 3

Run A:Basalt B:MAPP C:PP

% % %

1 0 5 95

2 8.125 3.75 88.125

3 23.125 3.75 73.125

4 0 0 100

5 15 5 80

6 35 0 65

7 0 5 95

8 17.5 0 82.5

9 21.6667 1.66667 76.6667

10 35 0 65

11 30 5 65

12 17.5 0 82.5

13 30 5 65

14 16.25 2.5 81.25

15 11.6667 1.66667 86.6667

16 0 2.5 97.5

17 0 0 100


Images of equipment's and blended granules

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Extruder✓ Screw Speed: 40 rpm✓ Chamber temp: 180 deg C

(9 Chambers)

To avoid Porosity in samples

✓ Extruded samples were dried

at 120 deg Celsius for 2 hrs

✓ Injection pressure increased

from 600 -700 bars

✓ Chamber temperatures: 180-180-180-180 deg C

✓ Mold temperature in injection molding increased

from 60 to 100 deg Celsius


Tensile test specimens

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ASTM D 638 Standard is followed to

- maintain the dimensions of the sample

- test procedure like speed

- evaluate tensile strength and tensile modulus


Results of Tensile Test for Basalt/PP/MAPP specimens

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• Addition of MAPP in composites indicates high ultimate tensile strength

and Young’s modulus upto 3.75 wt%, further decreases with increase in

MAPP

• Up to 28 % increase in UTS and 17 percent of increase in Young’s modulus

was observed


ANOVA and Two component mix results

for UTS

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Response 1: UTS

SourceSum of

Squaresdf

Mean

SquareF-value p-value

Model 4.781E+06 67.968E+0

56.59 0.0049 significant

⁽¹⁾Linear

Mixture2.583E+06 2

1.292E+0

610.69 0.0033

AB 10805.59 1 10805.59 0.0894 0.7710

AC 1471.54 1 1471.54 0.0122 0.9143

BC 3.99 1 3.99 0.0000 0.9955

ABC 1.721E+05 11.721E+0

51.42 0.2602

Residual 1.208E+06 101.208E+0

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Lack of Fit 1.100E+06 52.201E+0

510.18 0.0118 significant

Pure Error 1.081E+05 5 21625.40

Cor Total 5.989E+06 16

P-values indicate basalt fiber andpolypropylene are significant terms.


Contour and 3D surface plot for UTS

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➢ Significant improvement in BF-PP interaction with addition of MAPP➢ With increase in MAPP – an increase of 28 % in UTS at 30% Basalt fiber

Composite Materials and Engineering Center13

ANOVA and Two component mix results

for tensile modulus

SourceSum of

Squaresdf

Mean

SquareF-value p-value

Model 7.222E+10 6 1.204E+10 5.45 0.0096 significant

⁽¹⁾Linear

Mixture5.629E+10 2 2.815E+10 12.75 0.0018

AB 1.376E+09 1 1.376E+09 0.6230 0.4482

AC 1.172E+10 1 1.172E+10 5.31 0.0440

BC 1.634E+09 1 1.634E+09 0.7397 0.4099

ABC 5.694E+08 1 5.694E+08 0.2578 0.6226

Residual 2.208E+10 10 2.208E+09

Lack of Fit 1.533E+10 5 3.066E+09 2.27 0.1946not

significant

Pure Error 6.754E+09 5 1.351E+09

Cor Total 9.431E+10 16

Response 2: E

P-values indicate basalt fiber andpolypropylene are significant terms.

Composite Materials and Engineering Center14

Contour and 3D surface plot for tensile modulus

➢ Significant improvement in BF-PP interaction with addition of MAPP➢ With increase in MAPP – an increase of 17 % in Young’s modulus at 30% Basalt fiber


Rheological Behavior

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• Rheological behavior is studied to know the flow of

material under the circumstances in which they

respond with plastic flow instead of deforming

elastically due to the applied force

• The oscillatory experiments render the information on

both elastic and viscous properties of the formulations

and hence provide more detailed characterization of

dispersion and interface

• This study sought to develop the methodology to

produce basalt fiber/hemp fiber reinforced in

thermoplastic resin

• To evaluate complex viscosity(η), storage modulus

(G`), loss modulus (G``) and damping factor (Tan δ )

of these composites


Materials used

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Materials -

✓ Basalt fiber/Hemp fiber

✓ MAPP

✓ Polypropylene

Formulation –

Sample Name Basalt Fiber Hemp Fiber MAPP Polypro-pylene

15B15H70PP 15 15 00 70

15B15H5MA65PP 15 15 05 65

30B5MA65PP 30 00 05 65

30H5MA65PP 00 30 05 65


Experimentation

• The rheological behavior of Basalt fiber/hemp fiber

reinforced thermoplastic composite was investigated at

constant temperature over a wide range of frequencies

• The effect of hemp fiber and coupling agent on melt

rheological properties were investigated

• The tests were performed in the dynamic mode and 25-

mm parallel plate geometry with gap setting of about 2

mm

• The temperature was 200 deg C and the frequency,

varied between 0.1 and 200 rad/s

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Results

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✓ Viscosity increases with increasing Hemp fiber content

✓ Composite without MAPP showed the lowest viscosity compared to other samples in whole range of frequency

✓ Since the complex viscosity represents the viscoelastic resistance of the polymer melt during flow, a high viscosity implies a natural fiber (hemp hurds >300 microns) – matrix interaction

✓ The greater fiber–polymer interaction means greater the resistance to flow and greater the viscosity [1,2]


Results

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✓ Samples containing MAPP showed

higher viscosity than ones without

coupling agent. This can be

explained by the formation of strong

network of PP–fiber in the presence

of coupling agent

✓ When the storage modulus (G`) is

considered, the basalt/hemp fiber

composites have higher rigidity than

other composites, this increase

being strongly dependent on

proportion, which shows good fiber-

matrix adhesion existed [3]

✓ Viscous behavior becomes less pronounced with higher fiber loading in PP matrix and a

inclination to a slow shift from viscoelastic liquid-like to solid-like behavior occurs


Results

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▪ It is evident that G``

increased linearly with the

increase in frequency

▪ Hybrid composite of 15 wt%

basalt fiber and 15 wt% of

hemp fiber with 5 wt% MAPP

and 65 wt% of PP shows

better viscous properties over

other composites

▪ With increasing of hemp fiber, enhanced discontinuity may effect in the squeezing

out the polymer to the surface of the composites which is necessary to create

continuity on the surface [4]

▪ 30 wt% hemp fiber content, will affect the continuity due to the presence of fiber in

bulk of melt which results in decrease of viscous behavior (loss modulus)


Results

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❑ The ratio G’’/G’ decreases with

increase of hemp fiber content

❑ Tan δ shows to decrease with

the increase of the hemp fiber

which indicates the elastic

component is more affected by

hemp fiber loading than viscous

material

❑ Loss of energy by the hemp

fiber is less than storage

modulus due to stronger

mechanical lock up by fiber–

polymer interaction [5]

❑ with incorporation of fiber into polymer G' increased and G" decreased due to

the reduction of energy loss by porous material, hence tan δ decreased. The flat

section in the curve point out the relaxation of the fibers in composites [6]


Conclusions

• Increase in MAPP and basalt fiber will increase the mechanical

properties of the composites.

• The steady state viscosity of the composites increased with the

incorporation of fibers

• The composites with MAPP showed enhanced viscosity values due to

improved fiber matrix adhesion (backs up the result of DoE)

• The complex viscosities were quite high at the low frequency but

decreased with increasing frequency indicating a shear thinning

behavior of the fiber composites

• The G` and G``of the all the composites increased with increasing ωexcept for 30 wt% hemp fiber which exhibited decrease in storage

modulus with increasing frequency

• The damping factor decreased with increasing frequency for all

composites

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References

1. Smita Mohanty And Sanjay K. Nayak, Polymer Engineering And Science,

47 (10), 2007, 1634-1642.

2. Eddy Twite-kabamba, Ahmed Mechraoui And Denis Rodrigue, Polymer

Composites, 30 (10), 2009, 1401-1407.

3. T.Q. Li, M.P. Wolcott, Polymer Engineering And Science, 46 (4), 2006,

464-473.

4. 0. S. Carneiro And J. M. Maia, Polymer Composites, 21 (6) 2000, 960-969.

5. H. Azizi and I. Ghasemi, Polymer Composites, 30 (4), 2009, 429-435.

6. Anselm O. Ogah, Joseph N. Afiukwa and A. A. Nduji, Open Journal of

Polymer Chemistry, 4, 2014, 12-19.

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Acknowledgments

NSF I/UCRC Grants (#1439732, #1738669)

Center for Bioplastics and Biocomposites (CB2)

Project Mentors (from CB2 Industry Advisory Board)

Drew Geda, Hyundai

Tina Tosukhowong, GC Innovation

Jim Preston, RheTech

Nate Tortorella, John Deere

Alper Kiziltas, Ford

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Thank you

Questions ?

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