Polypropylene (PP) was used as matrix reinforced wi th calcium carbonate (CaCO 3 ) as filler in varying weight fractions to form composites by injection moulding in order to determine the effects of polymer melt flow rate, filler size, and filler content on mechanical properties. The res ults revealed that the composites of PP with higher melt flow rate provided greater values of tensile properties. it was found that tensile properties in creased as a function of increasing CaCO 3 content. In contrast the impact properties decreased as a function of increasing CaCO 3 content. Although, it was found that the addition of CaCO3 has a positive effect.

1. Physical and Mechanical Analysis of Poly Propylene- Calcium Carbonate Composites, Subita Bhagat,
Pardeep Kumar, Journal Impact Factor (2015): 8.5041 (Calculated by GISI) www.jifactor.com
www.iaeme.com/ ijaret.asp 1 editor@iaeme.com
*
Department of Chemical Engineering, Sant Longowal Institute of Engineering & Technology-India
** Guru Gobind Singh Refineries, Bathinda, Punjab- India
ABSTRACT
Polypropylene (PP) was used as matrix reinforced with calcium carbonate (CaCO3) as filler
in varying weight fractions to form composites by injection moulding in order to determine the
effects of polymer melt flow rate, filler size, and filler content on mechanical properties. The results
revealed that the composites of PP with higher melt flow rate provided greater values of tensile
properties. it was found that tensile properties increased as a function of increasing CaCO3 content.
In contrast the impact properties decreased as a function of increasing CaCO3 content. Although, it
was found that the addition of CaCO3 has a positive effect.
Keywords: Polypropylene, Calcium Carbonate, Ultimate Tensile Strength, Impact etc.
1. INTRODUCTION
Composite are the materials made of two or more constituents with different properties from
individual materials (Ashby, 1987). Constituent materials used in making composite are categorized
as: matrix (continuous phase) and reinforcement (discontinuous phase) and at least one portion of
each type is required. The matrix material surrounds and supports the reinforcement materials by
maintaining their relative positions. The reinforcements impart special mechanical and physical
properties to when added in polymer. The wide variety of available matrix and strengthening
materials allows the designer of the product or structure to choose an optimum combination.
Composites may be classified as follows, based on the type of matrix and reinforcement.
Composites are selected for such applications are mainly due to their high strength-to-weight
ratio, high tensile strength at elevated temperatures, high creep resistance and high toughness etc.
Typically, the reinforcing materials are strong with low densities while the matrix is usually a ductile
or tough material. If the composite is designed and fabricated correctly it combines the strength of
the reinforcement with the toughness of the matrix to achieve a combination of desirable properties
not available in any single traditional material. The strength of the composites depends primarily on
the amount, arrangement and type of fibre or particle reinforcement in the matrix.
Most commercial Polypropylene (PP) has an intermediate level of crystallinilty between low
density polyethylene and high density polyethylene. The relative orientation of each methyl group
relative to the methyl groups on neighbouring monomers has a strong effect on the polymer’s ability
PHYSICAL AND MECHANICAL ANALYSIS OF POLY
PROPYLENE- CALCIUM CARBONATE COMPOSITES
Subita Bhagat *
Pardeep Kumar**
Volume 6, Issue 6, June (2015), Pp. 01-05
Article ID: 20120150606001
International Journal of Advanced Research in Engineering and
Technology (IJARET)
© IAEME: www.iaeme.com/ ijaret.asp
ISSN 0976 - 6480 (Print)
ISSN 0976 - 6499 (Online)
IJARET
© I A E M E

2. Physical and Mechanical Analysis of Poly Propylene- Calcium Carbonate Composites, Subita Bhagat,
Pardeep Kumar, Journal Impact Factor (2015): 8.5041 (Calculated by GISI) www.jifactor.com
www.iaeme.com/ ijaret.asp 2 editor@iaeme.com
to form crystals, because each methyl group takes up space and constrains backbone bending. Like
most other vinyl polymers, pp can be made by addition polymerization. The material that results
from such a process has methyl groups arranged randomly, and so is called atactic.
2. EXPERIMENTAL
2.1 Materials Used
For the present study, a commercial available PP resin was used as the polymer matrix. The
CaCO3 was used as reinforcement for the preparation of PP/ CaCO3 Composites.
2.2 Preparation of Composite Samples
A weighed amount of PP resin and CaCO3 were taken and mixed properly by melt blending.
When the mixture became homogenous, Over mixing was avoided as it adversely affected the flow
characteristics and final properties of the composite sheets. When efficient mixing was achieved the
mixture was cast into the steel mould for processing.
3. CHARACTERIZATION OF COMPOSITE SAMPLES
The composite samples were tested for their physical and mechanical behavior.
3.1 Physical Testing
3.1a Moisture Content
Moisture content is the measure of the moisture present in the sample. Presence of moisture
has influence on the morphology and the mechanical properties of polymers. The moisture content of
the compounding ingredient should be within the limit, as higher moisture content may adversely
affect the performance of the polymeric goods. In some cases, a minimum amount of moisture
content is required to achieve a desired property through specific chemical reactions. Therefore, it is
essential to check the moisture content of the compounding ingredients, along with the other quality
control parameters. The presence of excess of moisture may result in the degradation of the sample
being stored and also cause processing as well as dimensional stability problems. The moisture
content of the sample was calculated by using formula:
=
ℎ − ℎ
ℎ
× 100
3.2b Melt Flow Index
The melt flow index is a measure of the ease of the melt of a thermoplastic polymer. It is
defined as the mass of polymer in grams flowing in 10 minutes through a capillary of specific
diameter and length by a pressure applied via prescribed alternative gravimetric weight at 1900
C.
Melt flow index is an indirect measure of molecular weight as high melt flow rate corresponding to
low molecular weight.
3.3c Bulk Density
Bulk density is a property of powders, granules and other divided solids. It is defined as the
mass of many particles divided by the total volume they occupy. The total volume may include
particle volume, inter-particle void volume and internal pore volume. Bulk density is not an intrinsic
property of a material but can change depending on how the material is handled. In order to find the
bulk density following relation is used:

3. Physical and Mechanical Analysis of Poly Propylene- Calcium Carbonate Composites, Subita Bhagat,
Pardeep Kumar, Journal Impact Factor (2015): 8.5041 (Calculated by GISI) www.jifactor.com
www.iaeme.com/ ijaret.asp 3 editor@iaeme.com
=
3.4d Viscosity Average Molecular Weight
Viscosity of a polymer solution depends on concentration and size (i.e. molecular weight) of
the dissolved polymer. By measuring the solution viscosity one can get an idea about the molecular
weight. Viscosity average molecular weight depends on a parameter which depends on the solvent
used to measure the viscosity. Therefore the measured molecular weight depends on the solvent
used.
Table 1: Physical properties of PP and CaCO3 observed as:
Properties PP CaCO3
Moisture content (%) 0.18 1.2
Melt flow index(gm/10 minutes) 13.71 ----
Bulk density (gm/cc) 0.45 0.29
Molecular weight 27581.51 -----
3.2 Mechanical Testing
3.2aTensile Strength
Tensile test is the most widely used method to evaluate the mechanical properties of the
resultant composites and also Predict Young’s modulus; the elongation at break. Tensile strength is
the maximum stress that a material can withstand while being stretched or pulled before failing or
breaking. It is an intensive property; therefore its value does not depend on the size of the test
specimen. However, it is dependent on other factors, such as the preparation of the specimen, the
presence of defects, and the temperature of the test environment and material used such
as alloys, composite materials, ceramics, plastics, and wood.
3.2b Impact Strength
The Impact strength is one of the most mechanical properties of a material. Impact is the
ability of a material to absorb mechanical energy in the process of deformation and fracture under
impact loading. The term impact strength as well as the term impact energy is also applied to the
amount of energy absorbed before fracture.
4. RESULT AND DISCUSSION
4.1 Tensile Testing
Tensile strength is a major property of composite material. The table 4.1 depicts the value for
tensile strength of PP/ CaCO3 composites with varying composition of calcium carbonate by weight.
Table 4.1: Values of ultimate tensile strength at different compositions of filler in PP/CaCO3
composites
Wt.% of CaCO3 in PP/CaCO3 composite Ultimate tensile strength (MPa)
0 4.7
10 5.6
20 5.9
25 7.5
30 6.4
40 3.6

4. Physical and Mechanical Analysis of Poly Propylene- Calcium Carbonate Composites, Subita Bhagat,
Pardeep Kumar, Journal Impact Factor (2015): 8.5041 (Calculated by GISI) www.jifactor.com
www.iaeme.com/ ijaret.asp 4 editor@iaeme.com
Figure 4.1: Variation of ultimate tensile strength of PP/CaCO3 composites
4.2 Impact Testing
The impact strength test performed on the composite sample. The table 4.2 depicts the value
showing decrease in impact strength of different sample and the results are plotted accordingly.
Table 4.2: Values of impact strength at different compositions of filler in PP/CaCO3 composites
Wt.% of CaCO3 in PP/CaCO3 composite Impact strength (j/m)
0 68
10 65
20 62
25 60
30 57
40 57
Figure 4.2: Variation of impact strength of PP/CaCO3 composites

5. Physical and Mechanical Analysis of Poly Propylene- Calcium Carbonate Composites, Subita Bhagat,
Pardeep Kumar, Journal Impact Factor (2015): 8.5041 (Calculated by GISI) www.jifactor.com
www.iaeme.com/ ijaret.asp 5 editor@iaeme.com
5. CONCLUSION
Different graphs were obtained for PP/CaCO3 composites with variation in filler
concentration. An attempt was made to explain the affect of filler content in the mechanical
behaviour of composites. From figure 4.1 it was concluded that as the filler concentration increased
to 25 %, tensile strength of PP/Calcium carbonate composites increases due to good filler matrix
interaction which enables more stress transfer red from the matrix to filler during external loading
and after that it declined due to poor interfacial bonding between filler and matrix. The Impact
strength decreased with increasing the filler composition as shown from figure 4.2. It was examined
that the impact property of polymeric materials were directly related to toughness of the material.
The impact energy is a measure of toughness, the higher the impact energy of material, higher the
material toughness and vice-versa.
ACKNOWLEDGEMENT
The authors gratefully acknowledge the following students for carrying out this investigation:
Aditya Singh, Bajarangee, Kamlesh Kumar and Sumant kr. Singh.
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