Experimental and theoretical study in polyester based thermal conductivity composite materials

Dissertant

Ibrahim, Hasan Ahmad

Thesis advisor

Mahmud, Ibtihal Abd al-Razzaq
Salih, Ahmad Abd Muhammad

University

University of Technology

Faculty

-

Department

Mechanical Engineering Department

University Country

Iraq

Degree

Master

Degree Date

2013

English Abstract

synthetic polymers such as unsaturated polyester are used widely in the many fields such as in the civil structure and in the external body of electrical machines .The properties of unsaturated polyester filled by aluminum and alumina were investigated in this study, and their thermal conductivity will be the central focus in this project.

The main objective of this project was to study the thermal conductivity of composite materials ,then to determine the best theoretical model that approves the experimental results .

Aluminum powder; alumina powder and aluminum fiber were added to polyester matrix (5wt % to 45wt %) and the Methyl Ethyl Ketone Peroxide (MEKP) was used as hardener by( 2%wt) at rom temperature .

In this work, the thermal conductivity was measured.

In addition, mechanical properties were also measured namely :- (Young's modulus; impact strength and hardness) to characterize these composites.

From this study, it was found that both fillers and fiber enhance the thermal conductivity to some extent .

The results show that the addition of 45wt% of aluminum powder and 45wt% of alumina powder in polyester resin increased the conductivity to 2.4times and 1.71times respectively.

The longitudinal thermal conductivity of aluminum fiber polyester matrix was increased to (120.4times) from the polyester alone.

Also the study shows that the thermal conductivity decreases with the increase of volume of particle sizes .

The mechanical results show that the Young modulus; impact strength and hardness were increased to 151%; 232% and 104.71% respectively by adding the aluminum powder to the polyester matrix; and to 186%; 163.2 % and 107.07 % respectively by adding alumina to the polyester matrix.

By using visual basic program, the experimental results were verified by three different theoretical models (Maxwell Equation, Lord Rayleigh Equation& Lewis and Nielsen Equation) used to predict the effective thermal conductivity for reinforced polyester by Al and Al2O3 powder until 35wt% and 45wt% respectively.

Four new empirical models were developed by using (Statistical Package for Social Science(SPSS)) software to predict the effective thermal conductivity of polyester matrix reinforced by aluminum powder ; alumina powder ; aluminum fiber transverse and aluminum fiber parallel with R (0.95 , 0.954 , 0.976 and 0.998) respectively, the models are : > Polyester & Al powder K1 = 0.46 + 0.013 *yP + 0.418 * P > Polyester & Al2O3 K2 = 0.472 + 0.0066 * pP + 0.342 *P > Polyester & Al fiber transverse K3 = 0.413 +0.018 *(pf + 0.062 *D > Polyester & Al fiber parallel K4 = -1.734 + 1.288 * qf + 0.835 * D K : Thermal conductivity W/m.k

Main Subjects

Engineering & Technology Sciences (Multidisciplinary)

Topics

• Composite materials

• APA
• MLA
• AMA

Language

English

Data Type

Arab Theses

Record ID

BIM-413157