Anisotropic Dispersal of Carbon Elements Lowers Electrical

Resistance in Carbon-LLDPE Composites

Agus Edy Pramono

, Yohannes Patrick

, Ahmad Maksum

, Isdawimah

and Nanik Indayaningsih

Master's Program in Applied Manufacturing Technology Engineering, Politeknik Negeri Jakarta

Jln. Prof. Dr. G.A. Siwabessy, Kampus UI. Depok 16425, Jawa-Barat, Indonesia

Master’s Program in Applied Electrical Engineering, Politeknik Negeri Jakarta

Jln. Prof. Dr. G.A. Siwabessy, Kampus UI. Depok 16425, Jawa-Barat, Indonesia

Research Centre for Physics, National Research, and Innovation Agency (BRIN),

Kawasan Puspiptek, Gd. 440-442, Tangerang Selatan, Banten 15310, Indonesia

Keywords: Carbon-LLDPE Composite, Low Electrical Resistance, Rice Husk Carbon, Hot Compaction,

Linear Low-Density Polyethylene.

Abstract: This article is about the electrical resistance generated by composite materials fabricated from rice husk

carbon and LLDPE polymers. The higher the weight content of carbon weights the lower the electrical

resistance of carbon-LLDPE composites. At the carbon-LLDPE composition ratio of 50:50 % wt., generating

electrical resistance R = 1506 Ω, at the ratio composition of carbon: LLDPE 60:40%wt., at a compaction

temperature of 150 degrees Celsius, it produces an electrical resistance of R= 237 Ω. Meanwhile, the lowest

electrical resistance of 57 Ω is generated by the composition of C7-3LLDPE, with a composition ratio of

carbon: LLDPE 70:30 % wt. This fact also occurs in other compaction temperature variants, namely 120

degrees Celsius, and 135 degrees Celsius. The distribution of weight of carbon elements in composites 49;

66; and 55% wt., respectively at C5-5LLDPE; C6-4LLDPE; C7-3LLDPE. Through testing with SEM EDX,

elements inside the composite can be identified. At a compaction temperature of 120 degrees Celsius, the

distribution of weight of carbon elements is 49% wt., the electrical resistance R shows 622.8 Ω, at the

distribution of weight of carbon elements 66.5% wt., the electrical resistance decreases to 349.2 Ω, and when

distribution of the weight of carbon elements at 55.4% wt. of the electricity resistance decreases to 94.5 Ω.

1 INTRODUCTION

This paper describes the electrical resistance

properties of carbon-LLDPE composite materials. In

this study, carbon produced from organic waste

produced low electrical resistance properties, and this

carbon serves as a composite filler with a matrix of

Linear low-density polyethylene (LLDPE). The

carbon elements dispersal in the LLDPE matrix in

this study was studied from the elemental distribution

map with SEM EDS. The content of other elements

https://orcid.org/0000-0002-2337-1977

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https://orcid.org/0000-0003-2148-8976

carried in composites also affects the electrical

resistance properties of composites. Anisotropic

carbon materials such as carbon nanotubes (CNTs)

and carbon fibre show very high thermal conductivity

(TC). However, due to their high electrical

conductivity, they have not been used in applications

requiring high TC and electrical insulation (Morishita

& Matsushita, 2021). The study examined the

influence of different carbon-based fillers on the

composite performance of electrically conductive

polymer mixtures. Specifically, the study examined

Pramono, A., Patrick, Y., Maksum, A., Isdawimah, . and Indayaningsih, N.

Anisotropic Dispersal of Carbon Elements Lowers Electrical Resistance in Carbon-LLDPE Composites.

DOI: 10.5220/0011712100003575

In Proceedings of the 5th International Conference on Applied Science and Technology on Engineering Science (iCAST-ES 2022), pages 62-67

ISBN: 978-989-758-619-4; ISSN: 2975-8246

and compared the effects of graphene (GR), carbon

nanotubes (CNTs) and black carbon (CB) on the

PC/ABS matrix with morphological investigation,

electrical and physical-mechanical characterization

(dal Lago et al., 2020). Electrically conductive

polymer composite (CPC) with bendable and

stretchable deformation. Fabrication composites

demonstrate comprehensively increased mechanical

modulus, thermal conductivity, and electrical

conductivity. The cut graphene is then applied as a

filler to make composites (Jiang et al., 2021). The

addition of ionic fluid (IL) to black conductive

styrene-butadiene-carbon rubber composites (CB)

can increase electrical conductivity and flexibility,

thus enabling use in applications such as small strain

sensors and stretchable conductors (Narongthong et

al., 2019). Experimental testing and analytical

modelling revealed that orthogonally conductive

filament-z weaving in the direction of thickness

through carbon-epoxy composites increased

electrical conductivity by creating interconnected

pathways for current flow (Abbasi et al., 2020).

Rubber-based conductive polymer composites are

shape-shifting and flexible, with different dimension

carbon fillers, including carbon black, single-

dimensional carbon nanotubes, two-dimensional

graphene, and their combination, into isoprene rubber

(IR) to create flexible EMI protective composites.

Both electrical, mechanical, and EMI shield

properties investigated (Wang et al., 2020). The study

investigated how temperature and relative humidity

affect the electrical resistance of strengthening carbon

fibre in polymer composites. The study describes the

use of hybrid composites in which the tight

circumference of carbon fibre is laminated inside

epoxy specimens reinforced by glass fibres. The

electrical resistance of carbon fibre is monitored

continuously, while the temperature or relative

humidity varies (Forintos & Czigany, 2020).

Structural changes were investigated using

simultaneous electrical rheological measurements at

shear deformations specified in conductive polymer

composites containing carbon fibre or carbon black.

This work presents a systematic study of the electrical

behaviour of composites with anisotropic micro

fillers under deformation in a liquid state. It was

found that composite electrical conductivity with

carbon fibre reacts very sensitively to mechanical

deformation (Starý & Krückel, 2018). Electrically

conductive composites are prepared by dispersing

various amounts of PPy-coated PPF in a polyurethane

matrix derived from castor oil. Polyurethane/PPy-

coated PPF composite (PU/PPF-PPy) shows higher

electrical conductivity than PU/PPy mixture with

similar filling content (Merlini et al., 2017). Carbon-

based composites are widely used in applications

such as in polymer composite bipolar plates. The

study was conducted to investigate the potential use

of milled carbon fibre as a conductive filler in

composites and adapt the General Effective Media

(GEM) model to predict the electrical conductivity of

polymer composites produced (Mohd Radzuan et al.,

2017). Mixed polypropylene/polyamide 6 (PA6)

melts, and multiwalled carbon nanotubes (CNTs) are

formed by compression, injection, and interval

injection moulding. The PA phase exists as an

isolated dispersed phase in a sea-island system with

different phase orientations and degrees of dispersion.

Conductive line can be formed without considering

phase morphology, when the CNTs content is high

enough. When the CNT content is low, the scattered

PA forms a non-elongated structure, which is

beneficial for electrical conductivity (Mi et al., 2021).

2 EXPERIMENTS

2.1 Material Preparation

Rice husks are carbonized at a temperature of 950C

at a rate of 2C/min resulting in electrically

conductive carbon. Carbon is ground and filtered to

obtain mesh particle size of 150, as a composite filler,

and LLDPE powder with mesh of 60 as matrix is

obtained from the commercial market. Note, based

on ISO 3146, melting point LLDPE 124C.

2.2 Sample Fabrication

Carbon and LLDPE are mixed evenly at a ratio of

50/50; 60/40; and 70/30% wt., compacted heat in

mould at temperature of 120C; 135C; and 150C,

generated electrical resistance test samples in square

form with a size of ± 10 × 10 × 5 mm.

2.3 Electrical Resistance Testing

Electrical resistance testing was conducted with

Keithley Instruments tool, The 2450 Source Meter®

Instrument, at BRIN physics laboratory, Serpong,

Indonesia. Electrical resistance testing is performed

by a four-point probe method following ASTM D257

standards (Julia A. King et al., 2007) (Sherman et al.,

2019). Each variant was tested for 5 specimens. The

number of test specimens is indicated in Table 1.

Anisotropic Dispersal of Carbon Elements Lowers Electrical Resistance in Carbon-LLDPE Composites

Table 1: Number of specimens.

Compositi

on ratio,

% wt.

Specimen

code

Hot compaction

temperature, C

120 135 150

Number of Specimen

50/50 C5-5LLDPE 5 5 5

60/40 C6-4LLDPE 5 5 5

70/30 C7-3LLDPE 5 5 5

2.4 SEM-EDS Testing

This test was conducted to observe the

microstructures and elements contained in the

carbon-LLDPE composite. The test was conducted

with microscopic scanning electron Hitachi SU 3500,

at brin physics laboratory, Serpong, Banten,

Indonesia.

3 RESULTS AND DISCUSSIONS

3.1 Electrical Resistance

Electrical resistance testing is intended to determine

the value of electrical resistance experienced by

carbon-LLDPE composites. The tendency that occurs

indicates that the higher the distribution content of

carbon particles, the lower the electrical resistance.

Figure 1: Electrical resistance and deviation.

This tendency is generated by all variations in the

temperature of the compaction process of the carbon-

LLDPE composite, as shown in Figure 1. At the

composition ratio of carbon-LLDPE of 50:50 % wt.

and at compaction temperature of 150C indicates the

value of electrical resistance R = 1506 Ω. At the

composition ratio of carbon: LLDPE 60:40% wt., at a

compaction temperature of 150C, it produces an

electrical resistance of R= 237 Ω. Meanwhile, the

lowest electrical resistance of 57 Ω is generated by

the composition of C7-3LLDPE, with a composition

ratio of carbon: LLDPE of 70:30 %wt. This fact also

occurs in other compaction temperature variants,

namely 120C, and 135C, as shown in Figure 2. So,

this study shows that the nature of the electricity

resistance that is getting down is a contribution from

carbon, while also pointing to the electrical

conductivity properties of carbon. Variations in heat

compaction temperature have a significant effect on

the composition of C5-5LLDPE which shows an

increase in electrical resistance when the temperature

reaches 150C. In the composition of C7-3LLDPE it

shows a decrease in electrical resistance when the

compaction temperature reaches 150C. The

temperature of LLDPE plastic melting according to

the standard at 124C, while in the melting study at

120C, 135C to 150C only affected rheology which

serves as a matrix of bonds between carbon particles.

Figure 2 shows, the higher the volume of LLDPE

weight, the higher the electrical resistance of the

composite. In the composition of C7-3LLDPE the

highest electrical resistance is indicated at the

compaction temperature of 120C, at the composition

of C6-4LLDPE the highest electrical resistance is

indicated at the compaction temperature of 135C,

and the composition of C5-5LLDPE the highest

electrical resistance is indicated at the compaction

temperature of 150C. Some articles indicate the

study of electrical resistance inside polymer

composites, for example, (Abbasi et al., 2020),

(Hayashida & Tanaka, 2012), (Sherman et al., 2019),

(dal Lago et al., 2020), (Morishita & Matsushita,

2021), (Bai et al., 2021), (Luo et al., 2021).

Figure 2: Sample code vs. compaction temperature vs.

electrical resistance.

3.2 Dispersal of Composite Carbon

Element

The distribution of carbon elements weights in this

study was investigated with SEM-EDX. The purpose

of observing the content of this element is to ascertain

what percentage of the weight of the carbon element

in the composite. The results of the investigation

showed the weight of the carbon element dominated

the carbon-LLDPE composite, as shown in Figure 3.

iCAST-ES 2022 - International Conference on Applied Science and Technology on Engineering Science

The weight of the dispersal of carbon elements in

composites is 49; 66; and 55 % wt., respectively C5-

5LLDPE; C6-4LLDPE; C7-3LLDPE. The content of

the next sequence element is the oxygen element

which is thought to contribute to lowering the

electrical resistance of the composite in this study.

Another element, Si, is also present in the composite,

but it is not thought to contribute to the decrease in

electrical resistance, because Si is more insulator. In

this composite study there are also other elements

with a small percentage of weight, <10% wt., namely

Mg, Al, P, Cl, K, Fe, Cu, Zn, Na, It, Ca, Mn, and Ni.

The elements are scattered unevenly within the

carbon-LLDPE composite. The higher the volume

weight of carbon elements in composites is shown to

be able to lower the electrical resistance of

composites, this fact occurs in all composition ratios

and all compaction temperatures, as shown in Figure

4. At a compaction temperature of 120C, the weight

of the carbon element distribution is 49%, the

electrical resistance R shows 622.8 Ω, at the carbon

element distribution weight of 66.5%, the electrical

resistance decreases to 349.2 Ω, and when the weight

of the carbon element distribution at 55.4% the

electric resistance decreases to 94.5 Ω.

Figure 3: Elements of composites.

Figure 4: Elect. Resistivity vs. carbon elements.

The same fact occurs also in composites with a

compaction temperature of 135C, when the weight

of the carbon element is at 49.3%, the electrical

resistance is at 855 Ω, when the weight of the carbon

element is at 66.5%, the electrical resistance becomes

477.8 Ω, and when the weight of the carbon element

is at 55.5%, the electrical resistance at this

compaction temperature shows 65.9 Ω. The same

fact subsequently occurs at a compaction temperature

of 150C, at the weight of the same carbon element

sequentially resulting in a decreased electrical

resistance that is, from 1506.3; 237; and 57 Ω. The

fact shows that the higher the weight of anisotropic

dispersal of the carbon elements in the composite

with LLDPE matrix can lower the electrical

resistance of the composite of this study.

Figure 5: Elements dispersal and composite microstructure.

Anisotropic Dispersal of Carbon Elements Lowers Electrical Resistance in Carbon-LLDPE Composites

3.3 Dispersal of Elements and

Micro-Structures

Figure 5 shows the dispersal of the elements inside

the carbon-LLDPE composite. The image also shows

micro cracks of the composite.

This fact indicates the presence of porosity in the

composite. The spectrum inside the image are

observation points with the EDX SEM test, which are

taken randomly based on the appearance of a unique

feature. Spectral features indicate different

compound elements, but all spectral points indicate

the presence of a dominant carbon content. The

percentage of the elements weight of the three sample

variants is shown in Table 2, with different element

weights at each point of the observation spectrum.

This fact indicates an uneven dispersal of the

elements (also carbon), and results in a different

degree of decrease in electrical resistance. Figure

5(a) is a composite with 50% carbon weight and 50

LLDPE weights, with a carbon element content of

49.3% wt., and at all points of the observation

spectrum there is carbon content. Composites with a

carbon content of 60% wt. and LLDPE 40% wt., the

distribution of elements shown in Figure 5(b), shows

a carbon element content of 66.6% wt. and all

observation points indicate the presence of carbon

elements. Meanwhile, the composition of 70% wt. of

carbon, and 30% wt. of LLDPE, the results of

observations at all spectral points show a carbon

element with a value of 55.4% wt. Observational

facts at spectral points also indicate the presence of

silica elements as the dominant element of the third

order after carbon, and oxygen. The presence of silica

in composites is suspected because the carbon

material comes from rice husk waste that contains a

lot of silica. Silica is more insulator. Meanwhile,

carbon from organic waste rice husks, with a

pyrolysis process of 950C can produce carbon with

low electrical resistance.

Table 2: Percent weight of elements.

Elements

C5-5LLDPE

C6-4LLDPE

C7-3LLDPE

C 49.27 66.46 55.41

O 26.46 20.96 25.02

Mg 0.04 0.01 0.01

Al 1.09 0.12 0.09

Si 15.95 11.84 12.83

P 0.28 0.11 0.09

Cl 0.01 0.01 0.01

K 1.61 0.31 0.17

Fe 0.22 0.12 4.31

Cu 3.11 - -

Zn 1.90 - -

Na 0.03 0.01 0.05

Ti 0.02 - -

Ca 0.01 0.06 1.36

Mn - - 0.06

Ni - - 0.60

% Wt. 100 100 100

4 CONCLUSIONS

This study has successfully fabricated carbon-

LLDPE composites with lower electrical resistance

properties when the volume of carbon weight is

increased, and so that these composites will also be

able to conduct electric current. The study also

showed pyrolysis at 950C produces carbon with low

electrical resistance. The study also showed the

results of composite engineering that unites basic

materials with opposite electrical properties into

materials that can lower electrical resistance. At the

composition ratio of carbon-LLDPE of 50:50 %wt.,

produces an electrical resistance of R = 1506 Ω. At

the composition ratio of carbon: LLDPE 60:40% wt.,

at a compaction temperature of 150C, it produces an

electrical resistance of R = 237 Ω. Meanwhile, the

lowest electrical resistance of 57 Ω is generated by

the composition of C7-3LLDPE, with a composition

ratio of carbon: LLDPE of 70:30 %wt. This fact also

occurs in other compaction temperature variants,

namely 120C, and 135C. The dispersal weight of

carbon elements in composites ranges from 49; 66;

and 55 % wt., respectively at C5-5LLDPE; C6-

4LLDPE; C7-3LLDPE. At a compaction temperature

of 120C, the dispersal weight of the carbon element

is 49%, the electrical resistance R shows 622.8 Ω, at

the distribution weight of carbon element of 66.5%,

the electrical resistance decreases to 349.2 Ω, and

when the dispersal weight of the carbon element at

55.4% the electric resistance decreases to 94.5 Ω.

ACKNOWLEDGEMENTS

Author thanks the Research Centre for Physics,

National Research, and Innovation Agency (BRIN).

Author thanks the Research and Community Service

Unit of Politeknik Negeri Jakarta. This research was

funded through the Higher Education Leading

Vocational Product Research scheme 2022. Contract

iCAST-ES 2022 - International Conference on Applied Science and Technology on Engineering Science

number: B.373/ PL3.18/PT.00.06/2022, June 28,

2022, Politeknik Negeri Jakarta.

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Anisotropic Dispersal of Carbon Elements Lowers Electrical Resistance in Carbon-LLDPE Composites