Mechanics of Nano, Micro and Macro Composite Structures Politecnico di Torino, 18-20 June 2012

A. J. M. Ferreira, E. Carrera (Editors)

http://paginas.fe.up.pt/~icnmmcs/

1

EFFECT OF CARBON BLACK ON THE MECHANICAL AND

THERMAL PROPERTIES OF LLDPE NANO COMPOSITES

M. A. AlMaadeed *, Mabrouk Ouederni

+, Nabil Madi

*, Noora AlQahtani

*, Maryam

AlEjji *

* Materials Technology Unit, Qatar University

Doha-Qatar, P.O. Box : 2713

e-mail: m.alali@qu.edu.qa, Noora.alqahtani@qu.edu.qa, web page: www.qu.edu.qa

+ Qatar Petrochemical Company, Qatar.

Doha-Qatar P.O. Box 756

e-mail: mouederni@qapco.com.qa, web page: http://www.qapco.com

Key words: Carbon Black, LLDPE, Mechanical properties, Thermal properties.

ABSTRACT

This work investigates the mechanical, thermal and morphological properties of carbon black

nano-composites, made from linear low density polyethylene (LLDPE) and carbon black as a

filler. A two-step process was used, extrusion followed by injection molding, to make

composite samples with a carbon black content of 5% ,10% and 20% wt. The mechanical and

morphological properties were characterized by tensile testing, hardness, maximum frictional

coefficient test, and scanning electron microscope (SEM). The results showed that 5% of

carbon black addition gave the maximum tensile strength, and coefficient of friction. The drop

in properties after adding more carbon black is due to agglomeration which has been seen

under SEM photos. This is explained in terms of the poor dispersion of carbon particles in the

polymer matrix at high loadings above 5%. Thermal stability of the composites has increased

with the addition of carbon black, but the melting and crystallization temperatures of the

polymer remained constant.

1. INTRODUCTION

In the last decade polymer nano composite materials have attracted great scientific and

industrial interest due to their improved properties at low filler contents as compared with the

micro and macro- or neat counterparts. They exhibit superior property enhancements in part

due to the tremendous surface area offered by the nano-particles (fillers). Different types of

polymers and fillers have been used so far to prepare nano composites. The fillers can be

layered clay, carbon nano-tubes, carbon black, silica etc. and polymers can be thermoplastics

M. A. AlMaadeed*, Mabrouk Ouederni

+, Nabil Madi

*, Noora AlQahtani

*, Maryam AlEjji

*

.

2

orthermosets (1-3) Polymer nanocomposites are innovative products having fillers on nano

meter scale dispersed in the resin matrix. By optimizing the filler concentration and nano size,

thermal properties and mechanical properties such as adhesion resistance, flexural strength,

modulus, toughness and hardness can be enhanced (4-5). The potential of producing these

materials with tailored properties at low cost are attractive for applications ranging from drug

delivery to corrosion prevention.

In the present work Carbon Black (CB) was used as a filler for preparing the LLDPE

nano composites. Carbon black is a readily available industrial by-product and has been used

for decades as convenient and cheap additive for thermoplastics as well as for rubbers (6).

CB has been added by the following concentrations weight percentages 5, 10 and 20 %.

Tremendous increase in mechanical properties was seen for the composite with 5% CB.

Higher concentrations of CB caused agglomeration and poor dispersion as seen by the SEM

photos. Further investigation of the effect of CB on the viscolelastic behavior of LLDPE is

being carried out by melt rheology analysis and will be presented in the poster.

Figure 1. Tensile Strength of CB reinforced LLDPE nano composites.

2. REFERENCES

1. M. Kato, A. Usuki, N. Hasegawa, H. Okamoto and M. Kawasumi, “Development and

applications of polyolefin and rubber clay nanocomposites”, invited review, Polymer

Journal (2011) 43, 583–593.

2. P. F. Rios ,A. Ophir

,S. Kenig

,R. Efrati

,L. Zonder

,R. Popovitz-Biro, “Impact of Injection-

Molding Processing Parameters on the Electrical, Mechanical, and Thermal Properties of

Thermoplastic/Carbon Nanotube Nanocomposites” ,Journal of Applied Polymer Science,

120, 1, 70–78, (2011)

3. A. Silva, K. Dahmouche, B. G. Soares, “Nanostructure anddynamic mechanical properties

of silane functionalized montmorillonite/epoxy nanocomposites”, Applied Clay Science 54

(2011) 151–158.

0

2

4

6

8

10

12

14

16

18

LLDPE LLDPE+5% CB LLDPE+10% CB LLDPE+20% CB

TE

NS

ILE

ST

RE

NG

TH

(M

pa

)

M. A. AlMaadeed*, Mabrouk Ouederni

+, Nabil Madi

*, Noora AlQahtani

*, Maryam AlEjji

*

.

3

4. P. K. Maji, P.K. Guchhait and A. K. Bhowmick, “Effect of nanoclays on physico-mechanical

properties and adhesion of polyester-based polyurethane nanocomposites: structure–property

correlations”, Journal of Material Science,44,21, 5861-5871,(2009).

5. E. Kontu, M. Niaounakis, “ Thermo Mechanical properties of LLDPE/Sio2 nano compsoits” ,

Polymer 47, (2006),1267-1280.

6. P. Potschke, M. Abdel Goad, S.Pengel, D. Jehnichen, J. E. Mark, D. Zhou and G. Heinrich,

“Comparisons among Electrical and Rheological Properties of Melt-Mixed Composites

containing various carbon nnao structures”, Journal of Macromolecular Science, Part A: Pure

and Applied Chemistry (2010), 47,12-19.

3. ACHNOWLEDGEMENT

The authors would like to thank the support from Materials Technology Unit at Qatar

University and the kind support from Qatar Petrochemical Company ( QAPCO). Also want to

thank Noorulnissa Khanim for the analysis and fruitful discussion.