Determination of calcium carbonate in low density polyethylene

Identifier:  TFG:1199

Handle: https://hdl.handle.net/20.500.11797/TFG1199

Authors:  Margalef Vaqué, Lluís

Abstract:
ABSTRACT This project has been developed at the production plant that the chemical company “Transformadora de Etileno (TDE AIE)” has in Tarragona, which its main business is definitely the synthesis of polyethylene. During the production process of 2308FG (a kind of polyethylene), an appropriate amount of CaCO3 is added because it turns out in an improvement of the mechanical characteristics of the final product. However, those mechanical characteristics couldn’t be the best ones if the final concentration of CaCO3 were below or above a pre-defined range (1.800 – 2.200 mg/l). Therefore, there is the need of a quantitative method capable to determine if the CaCO3 amount in the final product is located inside the required range. Because of the plant is running in a continuous way it’s also important to have the results as soon as possible. So, the aim of this project is to develop an analytical method to determine the CaCO3 concentration in the final product, in the fastest and cheapest way and taking into account the equipment available in TDE Laboratory. After some documental research, it has been decided to develop a method using an FTIR device. Some test has been done, however the results haven’t been the expected ones. The concentration of CaCO3 in the final product is really variable in each part of it, and this FTIR is not appropriate because this only analyzes a small part of the sample (just the point where of the light beam strikes). As a consequence, the result is not representative of the whole sample and doesn’t give an idea if the batch is fulfilling or not the quality specifications. Then, a gravimetric method has been developed and it turned to be the best one. With few sample treatment, in a relative small amount of time and using a muffle available in the Laboratory it’s possible to determine if the product meet the target CaCO3 concentration. So, as a conclusion, the best procedure to determine if the CaCO3 amount in polyethylene fulfills the quality requirements tuned to be the gravimetric method.