MECHANICAL, RHEOLOGICAL, AND THERMAL PROPERTIES OF CALCIUM CARBONATE FILLED PP/LLDPE COMPOSITE Submitted by Eng: Mustafa . Abu Ghalia E-mail: firstname.lastname@example.org
Introduction Blending of polymers is a simple technology used to achieve specified material properties without syntheses of specialized polymer materials. Polypropylene (PP) has been widely used for injection molding, extrusion, and film blowing processes due to the remarkable properties. However, polypropylene exhibits a poor impact resistance in specific applications particularly at low temperature. PP has a relatively high glass transition temperature (Tg) which reduced its application due to its brittleness
For this reason, PP has blended with other polymers to improve the impact strength. Linear Low Density Polyethylene (LLDPE) was chosen because: can enhance the impact strength without reducing the tensile strength and modulus to a large extent. (b) Similarity in chemical structure, and therefore better compatibility
Problem statements • Adding filler to polymers will effect the following: • Increase stiffness (modulus) but reduced toughness (impact • strength) • Increase the viscosity and decrease melt elasticity of the polymer. • Increase the thermal stability of composites • Hence, study the mechanical, rheological, and thermal properties • will be important to produce a materials with balance mechanical • and rheological properties.
The questions that require to be answered in this area of the • research are: • What is the optimum of CaCO3 treat should be added to the • PP/LLDPE to achieve a good mechanical, thermal, rheological • properties • 2. Under what conditions is it possible to increase both of stiffness and impact resistance for PP? also what is the effect of coupling agent on the mechanical, rheological properties. • In spite of plenty studies have been reported on using CaCO3 • filled Polypropylene, however. There is no much study have been carried out to using calcium carbonate filled to PP/LLDPE,
Objectives of research The objectives of this research are: 1-To study the effects of LLDPE contents to PP on mechanical, thermal, and rheological properties. 2- To investiage the effect of CaCO3content on mechanical, thermal and rheological properties of PP/LLDPE composites. 3- To determine the effect of silane coupling agent on mechanical, thermal and rheological properties incorporating calcium carbonate into PP/LLDPE composites. 4- To study the effect of the weight ratios of the blends PP/LLDPE,CaCO on the processing parameters such as processing temperatures, pressure at the dies, dynamic viscosity,and torque of the blending processes, shear stress and shear rate.
Benefits of using linear low density polyethylene as blend to PP The significance reasons of using LLDPE to PP can be demonstrated in the table below,
Filled polypropylene Properties of typical filled and unfilled Polypropylene (Seymour, 1990). The properties of typical filled and unfilled polypropylene depend on the chemical composition and shape of the fillers,
Advantages of usingcalcium carbonate (CaCO3) in polypropylene matrix. According to Zuiderduin et al. (2003), which confirmed that CaCO3 has indeed ability not only to increase the stiffness but also improving the impact strength of Polypropylene, particularly when it is treated, therefore. There are reasons for using calcium carbonate in polymers including: • Cost effectiveness • Improve color characteristics. • Increase rigidity and thermal conductivity. • Control rheological properties. • Making easier processing. • Improve heat resistance, and opacity. • Regulate thermal expansion and shrinkage
Polypropylene and Polyethylene blends - According to the recent published papers that had been studied, the blends PP with PE can be concluded at the following: • Improve some of the mechanical properties of the composite such as elongation at break and impact strength. • improved both the motor torque and decrease the pressure at die. • Obtain partial miscibility of the blend. • LLDPE acted as an impact modifier.
Effects calcium carbonate (CaCO3) on the polypropylene. According to Thio et al.,(2002) studied the toughening of isotactic PP with CaCO3 particles. They found that particle size has a key effect on the improvement of impact strength of PP matrix. Yong Zhang et., al (2003), and Karian.H.G (1999) reported that the mechanical properties of the CaCO3-polymer composites depend strongly on purity, shape, particle size, weight ratio of calcium carbonate, and the interaction between the particles and polymer chains.
Effect silane coupling agent on the polypropylene blends Coupling agents are bifunctional molecules containing organic and inorganic ends, improve the mechanical properties and chemical resistance of composites by enhancing adhesion across the polymer-filler interface. Ethoxy group Amino group CaCO3 PP/LLDPE
Recent studies can be concluded to the following: The previous studies showed that the LLDPE acts an impact modifier for PP. The studies reveal that there was only degree of miscibility in the PP and LLDPE. By using CaCO3 as filler in the polymer matrix, and CaCO3 particles tend to agglomerate together. Particularly, at higher weight ratio in the absent of coupling agent. The mechanical properties of PP-LLDPE depend strongly on the weight ratio. It's depends also on the coupling agent and chemical structure of the coupling agent. This study will focus on the application CaCO3 as a filler with PP LLDPE blend and silane compound contains amino group will be used to increase the adhesion between CaCO3 particles and polymer matrix. As results the impact and stiffness properties may improved.
Polypropylene Polypropylene pellets will be purchased from HYOCUNG CO, Korea. It’s code PPR R200P. Some of the physical and the mechanical properties of PPR R200P are presented in table below
Linear Low Density polyethylene (LLDPE) will be used in this work and samples will be obtained from Raslanuf Company in Libya, LLDPE, grade is 181N will be selected with MFI 1.0 g/min, density of 0.918 g/cm3, the specification of grade 181 N LLDPE is listed in table Linear Low Density Polyethylene
Calcium Carbonate Libyan calcium carbonate CaCO3 will be obtained from Aljouf Company, Libya, particle size 2.7µm. It will be used and the chemical composition of CaCO3 is shown in table below
Coupling Agent 3-Aminopropyltriethoxy silane will be used as coupling agent in this research to increase the compatibility between CaCO3 and polymer chains. It will be obtained from Italmar (Thailand) Co., the coupling agent will be use without any purification. And the commercial name for this silane as (AMPTES). The chemical structure is presented in the structure below
Coupling Agent Treatment of CaCO3 CaCO3 Blending of PP/LLDPE +CaCO3 Processing Temperature 190 0C Characterization Rheology Mechanical Test Thermal Analysis Morphology
Expected Results In the first research will be used random copolymer polypropylene behavior of a series percentages of blends Libyan linear low density polyethylene. Some expected results that can be obtained from this study are: • LLDPE act as impact modify that probably will be expected to increase the impact resistance. • Mechanical properties will be expected to increase at specific weight ratios of Libyan CaCO3 treat. • Due to easy processability and properties of CaCO3 is expect to increase some of the thermal and rheological properties. • Silane coupling agent will be expected to results superior mechanical properties