PHYSICAL AND MECHANICAL ANALYSIS OF POLY PROPYLENE- CALCIUM CARBONATE COMPOSITES

PHYSICAL AND MECHANICAL ANALYSIS OF POLY PROPYLENE- CALCIUM CARBONATE COMPOSITES Physical and Mechanical Analysis of Poly Propylene- Calcium Carbonat...
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PHYSICAL AND MECHANICAL ANALYSIS OF POLY PROPYLENE- CALCIUM CARBONATE COMPOSITES

Physical and Mechanical Analysis of Poly Propylene- Calcium Carbonate Composites, Subita Bhagat, Pardeep Kumar

Subita Bhagat * Pardeep Kumar** Volume 6, Issue 6, June (2015), Pp. 01-05 Article ID: IJARET_06_06_001 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 ©IAEME

*

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 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. 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 www.iaeme.com/ ijaret.asp

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Physical and Mechanical Analysis of Poly Propylene- Calcium Carbonate Composites, Subita Bhagat, Pardeep Kumar

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:

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 190 0C. 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: www.iaeme.com/ ijaret.asp

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Physical and Mechanical Analysis of Poly Propylene- Calcium Carbonate Composites, Subita Bhagat, Pardeep Kumar

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 Moisture content (%) Melt flow index(gm/10 minutes) Bulk density (gm/cc) Molecular weight

PP 0.18 13.71 0.45 27581.51

CaCO3 1.2 ---0.29 -----

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 10 20 25 30 40

4.7 5.6 5.9 7.5 6.4 3.6

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Physical and Mechanical Analysis of Poly Propylene- Calcium Carbonate Composites, Subita Bhagat, Pardeep Kumar

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 10 20 25 30 40

68 65 62 60 57 57

Figure 4.2: Variation of impact strength of PP/CaCO3 composites

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Physical and Mechanical Analysis of Poly Propylene- Calcium Carbonate Composites, Subita Bhagat, Pardeep Kumar

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. REFERENCES [1] [2] [3] [4] [5] [6] [7] [8]

Kulshreshtha, A.K., Vasile, C. 2002. Handbook of Polymer Blends and Composites. Lee, H and Neville, K. 1967. Handbook of Epoxy resins, Mc Graw-Hill, New York. Peters, S.T. 1998. Handbook of Composites, Chapman and Hall, London. Subramanian,C., Asaithambi,P. 1986 Friction and Wear of Epoxy Resin Containing Graphite. Bhattacharya, S.K. 1986. Metal filled polymers: properties and applications. Agag T., Koga T., Takeichi T. Polymer 2001; 42:3399. Zhang W., Chen D., Zhao Q., Fang Y. Polymer 2003; 44:7953. Attel manjunath, Dr. D V Girish, “Effect of Short Glass Fiber Reinforcement on Characteristics of Polymer Matrix (Polycarbonate) - An Experimental Study” International Journal of Mechanical Engineering & Technology (IJMET), Volume 1, Issue 1, 2010, pp. 124 - 133, ISSN Print: 0976 – 6340, ISSN Online: 0976 – 6359

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