15
1
chemical bond significantly improves the processability of filler in
the polymeric composite. The term reinforced polymer is often used
for composites with fibrous or reinforcing materials, while filled
polymers are the materials which consist of particulate fillers. A vast
number of filled polymers are used today. The most common filler
for polymers are calcium carbonate, talc, and silica.
1.5 Properties of Reinforcements
The mechanical properties of composites depend on many factors,
such as the material of the fibre, the fibres’ orientations, and the
fibre architecture. The properties of high-temperature reinforcing
fibres and thermoplastic fibres are provided in . Table 1.6.
The properties of natural fibres and select conventional materials are presented in . Table 1.7.
Woven fabrics have led to easier handling and layup of composite laminates. In addition, composites made out of woven fabric are
. Table 1.6 Properties of reinforcing fibres [9–12]
Serial no.
Material
Density
(g/cm 3 )
Tensile
strength (MPa)
Tensile modulus
(GPa)
Elongation at
break (%)
High- temperature fibres
1.
E- glass
2.54
3500
72.4
3
2.
S- glass
2.48
4600
85.5
2
3.
R-glass
2.58
4400
84.8
2
4.
Carbon (high strength)
1.8
4000
390
1–2
5.
Carbon (high modulus)
1.9
2100
390
1
6.
Boron
2.63
3500
415
1
7.
Aramid (Kevlar 49)
1.44
3500
125
1.2
8.
Aramid (Kevlar 149)
1.47
3400
185
3
9.
Silica
2.19
5800
72.4
3
10.
Silicon carbide
3.18
2100
480
2
11.
Silicon nitride
3.2
410
310
2
12.
Alumina
3.7
1700
370
2
13.
Basalt
2.7
4840
89
3.15
Thermoplastic fibres
14.
Nylon
1.44
65
3
52
15.
Peek
1.27
90
4
60
16.
Polyester
1.5
45
3
50
17.
UHMWPE
0.94
1500
20
3
18.
Polypropylene
0.96
200
6
70
1.5 · Properties of Reinforcements