Influence of microwave power on mechanical properties of microwave-cured polyethylene/coir composites

ABSTRACT

The present work deals with investigating the influence of microwave power on mechanical properties of 20 wt.% coir reinforced high-density polyethylene (HDPE) composites. Chopped coir/HDPE composites were fabricated using various microwave power levels (360 W, 540 W, 720 W and 900 W). The XRD analysis of the specimens reveals that crystallinity index in various specimens was in the range of 79.54% to 84.59%. The specimen cured at 360 W exhibited a maximum tensile strength of 29.5 ± 1.5 MPa, which is 28.26% greater than composite cured at 900 W (23 ± 1.5 MPa). Flexural strength of specimen cured at 360 W was maximum (37.74 ± 2 MPa).

摘要

研究了微波功率对20wt.%Coir增强高密度聚乙烯（HDPE）复合材料力学性能的影响。采用不同微波功率水平（360W、540W、720W和900W）制备了斩波COIR／HDPE复合材料。试样的XRD分析表明，不同试样的结晶度指数在79.54%～84.59%之间。在360W下固化的试样的最大抗拉强度为29.5±1.5MPa,比900W(23±1.5MPa)下固化的复合材料高28.26%。360W固化试样的弯曲强度最大（37.74±2 MPa）

KEYWORDS:

• Coir fiber
• polyethylene
• XRD
• microwave curing
• mechanical properties
• SEM

关键词:

• 椰壳纤维
• 聚乙烯
• 微波固化
• 力学性能

Nomenclature

${\epsilon }^{\ast }$	=	Complex permittivity
ε’	=	Dielectric constant
ε’’	=	Dielectric loss factor
P	=	Power density in the material (W/m3)
ω	=	Angular frequency of the incident microwaves (s−1)
${\epsilon }_{eff}^{{ }^{\prime \prime }}$	=	Effective dielectric loss factor
${\epsilon }_0$	=	Permittivity of free space (8.854 × 10−12 F/m)
Erms	=	Electric field strength (V/m)
σ	=	Electric conductivity
εR	=	Relaxed permittivity of the molecule
εU	=	Unrelaxed permittivity of the molecule
τ	=	Relaxation time
τ0	=	Pre-exponential factor
Ea	=	Activation energy
k	=	Boltzmann’s constant
T	=	Temperature
I002	=	Maximum intensity of the (002) lattice diffraction peak
Iam	=	Intensity scattered by the amorphous part of the sample
F	=	Flexural load
L	=	Span length of the specimen
d	=	Displacement
b	=	Width of the specimen
h	=	Height of specimen

Acknowledgements

First author, Manoj, gratefully acknowledges Ministry of Human Resource and Development (MHRD), Government of India for providing fellowship for the PhD work.

Additional information

Funding

This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.