NATIONAL TEXTILE UNIVERSITY, FAISALABADFACULTY OF ENGINEERING AND TECHNOLOGY DEPARTMENT OF MATERIAL Submitted by Submitted to Department Date Course code Usman haider Dr wasif Polymer engneering 19-12-2023 PE-2106 Experiment No: 8 Objective: Prepation of polystyrene by Emulsifier Abstract: This laboratory report details the synthesis of polystyrene through emulsion polymerization. The procedure involves the emulsification of styrene monomer in water using an emulsifying agent. The emulsion is initiated through the addition of a suitable initiator, leading to the growth of polystyrene chains. Throughout the process, temperature control and initiator dosage are carefully managed to achieve the desired polymer properties. The reaction is terminated at the appropriate stage, and the resulting polystyrene latex is recovered, often through coagulation and separation techniques. The collected latex is subsequently dried to obtain the final polystyrene polymer. This report outlines the experimental setup, procedure, and key considerations in the synthesis process, providing insights into the successful preparation of polystyrene via emulsion polymerization in the laboratory setting Introduction: Polystyrene, a versatile and widely used synthetic polymer, finds applications in various industries ranging from packaging materials to consumer goods. Its production often involves emulsion polymerization, a method known for its efficiency and scalability. Emulsion polymerization is particularly advantageous for the synthesis of polystyrene due to its ability to yield high molecular weight polymers with controlled properties.The process of emulsion polymerization involves the dispersion of hydrophobic monomers, such as styrene, in an aqueous medium with the aid of an emulsifying agent. This dispersion forms stable emulsions, preventing the coalescence of monomer droplets and facilitating controlled polymerization. of. Fig 1 polystyrene This laboratory report outlines the systematic preparation of polystyrene through emulsion polymerization. By elucidating the experimental setup, methodology, and key parameters, this study aims to provide a comprehensive understanding of the factors influencing the successful synthesis of polystyrene in a controlled laboratory environment. The insights gained from this investigation contribute to the optimization of production processes, ensuring the reproducibility and quality of polystyrene for diverse industrial applications Apparatus : Reaction Vessel:A suitable reaction vessel equipped with a stirring mechanism to facilitate thorough mixing of reactants. The vessel should be capable of maintaining a controlled temperature throughout the polymerization process. Condenser:A water-cooled condenser to prevent the escape of volatile substances and maintain a closed system during the polymerization reaction. Thermometer:A calibrated thermometer to monitor and control the temperature of the reaction, ensuring optimal conditions for polymerization. Emulsifying Agent:An emulsifying agent or surfactant, such as sodium dodecyl sulfate, to stabilize the emulsion and disperse the hydrophobic monomer in the aqueous medium. Styrene Monomer:High-purity styrene monomer, the precursor for polystyrene, to be added to the emulsion. Initiator:A suitable chemical initiator, such as potassium persulfate or AIBN (azo-bisisobutyronitrile), to initiate the polymerization reaction Procedure: Preparation of Emulsion: Place a clean and dry reaction vessel equipped with a stirring mechanism. Add a prede 60ml amount of water to the vessel. Introduce the selected emulsifying agent (e.g.poly vinyl alchol) to the water while stirring to form a stable emulsion . Inert Atmosphere Setup: Purge the reaction vessel with an inert gas (e.g., nitrogen) to create an oxygen-free environment, preventing undesired side reactions. Monomer Addition: Gradually introduce the styrene 10ml monomer into the emulsion while maintaining constant stirring. Continue stirring to ensure uniform dispersion of the monomer droplets in the emulsion. Initiation: Add the chosen initiator (e.g.5ml benzyl peroxide) to initiate the polymerization reaction.Maintain a controlled temperature throughout the reaction, typically in the range of 50-70°C, depending on the initiator and reaction conditions. Polymerization: Observe the gradual formation of polystyrene chains as the polymerization proceeds. Adjust the stirring speed and temperature as needed to optimize the reaction kinetics Product Separation: Separate the resulting polystyrene latex from the aqueous medium using appropriate separation techniques such as coagulation or centrifugation. Drying: Collect the separated polystyrene latex and transfer it to a drying apparatus. Dry the polystyrene product to remove any remaining water. Fig 2 polystyrene Application: Polystyrene, a versatile polymer with a wide range of beneficial properties, finds applications in various industries. Some of the key applications of polystyrene include: Packaging Materials:Expanded polystyrene (EPS) is commonly used for packaging materials, including protective packaging for fragile items and disposable foodservice items like foam cups and trays. Insulation:EPS is an excellent thermal insulator, making it a preferred material for insulation in construction, packaging, and appliances. Disposable Products:Polystyrene's low cost and ease of manufacturing make it suitable for the production of disposable products such as cutlery, plates, and food containers. Medical Applications:High-impact polystyrene (HIPS) is used in the production of medical devices, including petri dishes, sample cups, and components of medical equipment. Consumer Goods:Polystyrene is employed in the manufacturing of various consumer goods, including toys, CD cases, and electronic housings