Match the following: List 1 (Polymer) 1\. Bakelite 2\. Dacron 3\. Nylon-66 4\. Buna-S List 2 (Polymerizing units) (1) Butadiene and styrene (2) Phenol and methanal (3) 1,2 -dihydrooxyethane and dimethyl terephthalate (4) Urea and methanal (5) 1,6 -hexanedioic acid and 1 , 6 -diamino hexane

Bakelite, recognized as the first synthetic plastic, is a hard and heat-resistant material used in electrical insulators and household items. The polymerization process involves a step called condensation reaction where phenol (C₆H₅OH) reacts with methanal (HCHO), also known as formaldehyde. During the reaction, which is catalyzed by an acid or base, the phenol and methanal undergo a cross-linking process to form a three-dimensional network which cures into an infusible and insoluble resin. This process creates long chains of phenol-formaldehyde molecules that are highly cross-linked, giving Bakelite its unique properties.

One significant distinction in the manufacturing of Bakelite is the elimination of water molecules as a byproduct, which is a characteristic of many condensation polymerizations. Its creation marks the beginning of modern polymer science, making the study of Bakelite polymerization crucial for understanding the foundations of the industry.

Dacron is a trade name for polyethylene terephthalate (PET) and is widely utilized in the manufacture of textiles and packaging materials due to its strength, durability, and resistance to moisture. To synthesize Dacron, two main chemical components are required: ethylene glycol (1,2-dihydroxyethane) and dimethyl terephthalate. These react through a polymerization process known as esterification.

During the synthesis of Dacron, ethylene glycol and dimethyl terephthalate are combined at high temperatures with catalysts. The esterification reaction forms a repeating unit that contains an ester group, hence it's classified as a polyester. Students must understand the significance of maintaining specific conditions like temperature and pressure to control the molecular weight of the polymer, which in turn contributes to the desirable attributes of Dacron, such as tenacity and elasticity.

Nylon-66 is a type of polyamide that is known for its stiffness, strength, and excellent thermal resistance, making it suitable for applications such as automotive parts, industrial fibers, and clothing. To create Nylon-66, two main ingredients are polymerized: hexanedioic acid (adipic acid) and 1,6-diaminohexane (hexamethylene diamine).

The production involves a condensation polymerization reaction similar to the one used for Bakelite, but instead of phenol and methanal, carboxylic acid and amine groups react to form amide linkages in the long chains of Nylon-66, referred to as polyamides. A molecule of water is eliminated for each amide linkage formed. Key in the study of Nylon-66 production is the understanding of how the chain length, or degree of polymerization, affects the material properties, as well as the careful control of reaction conditions to achieve the desired quality in the final product.

Buna-S, also known as Styrene-Butadiene Rubber (SBR), is a synthetic rubber that displays good abrasion resistance and is commonly used in car tires. As a copolymer, it is made from the polymerization of two monomers: butadiene (a diene) and styrene (a vinyl compound). The structure of Buna-S is characterized by the random distribution of the butadiene and styrene units.

The copolymerization process of Buna-S requires precise control of reaction conditions, such as temperature and pressure, and a catalyst to initiate the polymerization. The alternating arrangement of the two monomers determines the physical properties of the rubber obtained. By adjusting the ratio of butadiene to styrene, manufacturers can modify the toughness and elasticity of Buna-S to suit various applications. The study of Buna-S copolymer structure gives students insight into how the arrangement and proportion of monomer units in copolymers can influence the properties of the final polymer product.