Economics of plastics processingThe economics of plastics processing is determined by the type of process. Plastics can be processed with the following methods: machining, compression molding, transfer molding, injection molding, extrusion, rotational molding, blow molding, thermoforming, casting, forging, and foam molding. Processing methods are selected based on equipment cost, production rate, tooling cost, and build volume. High equipment and tooling cost methods are typically used for large production volumes whereas low - medium equipment cost and tooling cost methods are used for low production volumes.
Fiber cropFiber crops are field crops grown for their fibers, which are traditionally used to make paper, cloth, or rope. Fiber crops are characterized by having a large concentration of cellulose, which is what gives them their strength. The fibers may be chemically modified, like in viscose (used to make rayon and cellophane). In recent years, materials scientists have begun exploring further use of these fibers in composite materials. Due to cellulose being the main factor of a plant fiber's strength, this is what scientists are looking to manipulate to create different types of fibers.
High-performance plasticsHigh-performance plastics are plastics that meet higher requirements than standard or engineering plastics. They are more expensive and used in smaller amounts. Plastic#Special purpose plastics High performance plastics differ from standard plastics and engineering plastics primarily by their temperature stability, but also by their chemical resistance and mechanical properties, production quantity, and price. There are many synonyms for the term high-performance plastics, such as: high temperature plastics, high-performance polymers, high performance thermoplastics or high-tech plastics.
MonomerIn chemistry, a monomer (ˈmɒnəmər ; mono-, "one" + -mer, "part") is a molecule that can react together with other monomer molecules to form a larger polymer chain or three-dimensional network in a process called polymerization. Monomers can be classified in many ways. They can be subdivided into two classes, depending on the kind of the polymer that they form. Monomers that participate in condensation polymerization have a different stoichiometry than monomers that participate in addition polymerization: Other classifications include: natural vs synthetic monomers, e.
Natural fiberNatural fibers or natural fibres (see spelling differences) are fibers that are produced by geological processes, or from the bodies of plants or animals. They can be used as a component of composite materials, where the orientation of fibers impacts the properties. Natural fibers can also be matted into sheets to make paper or felt. The earliest evidence of humans using fibers is the discovery of wool and dyed flax fibers found in a prehistoric cave in the Republic of Georgia that date back to 36,000 BP.
Anionic addition polymerizationIn polymer chemistry, anionic addition polymerization is a form of chain-growth polymerization or addition polymerization that involves the polymerization of monomers initiated with anions. The type of reaction has many manifestations, but traditionally vinyl monomers are used. Often anionic polymerization involves living polymerizations, which allows control of structure and composition. As early as 1936, Karl Ziegler proposed that anionic polymerization of styrene and butadiene by consecutive addition of monomer to an alkyl lithium initiator occurred without chain transfer or termination.
PolystyrenePolystyrene (PS) ˌpɒliˈstaɪriːn is a synthetic polymer made from monomers of the aromatic hydrocarbon styrene. Polystyrene can be solid or foamed. General-purpose polystyrene is clear, hard, and brittle. It is an inexpensive resin per unit weight. It is a poor barrier to oxygen and water vapor and has a relatively low melting point. Polystyrene is one of the most widely used plastics, with the scale of its production being several million tonnes per year. Polystyrene is naturally transparent, but can be colored with colorants.
Polyethylene terephthalatePolyethylene terephthalate (or poly(ethylene terephthalate), PET, PETE, or the obsolete PETP or PET-P), is the most common thermoplastic polymer resin of the polyester family and is used in fibres for clothing, containers for liquids and foods, and thermoforming for manufacturing, and in combination with glass fibre for engineering resins. In 2016, annual production of PET was 56 million tons. The biggest application is in fibres (in excess of 60%), with bottle production accounting for about 30% of global demand.
EthyleneEthylene (IUPAC name: ethene) is a hydrocarbon which has the formula or . It is a colourless, flammable gas with a faint "sweet and musky" odour when pure. It is the simplest alkene (a hydrocarbon with carbon–carbon double bonds). Ethylene is widely used in the chemical industry, and its worldwide production (over 150 million tonnes in 2016) exceeds that of any other organic compound. Much of this production goes toward polyethylene, a widely used plastic containing polymer chains of ethylene units in various chain lengths.
Ultra-high-molecular-weight polyethyleneUltra-high-molecular-weight polyethylene (UHMWPE, UHMW) is a subset of the thermoplastic polyethylene. Also known as high-modulus polyethylene (HMPE), it has extremely long chains, with a molecular mass usually between 3.5 and 7.5 million amu. The longer chain serves to transfer load more effectively to the polymer backbone by strengthening intermolecular interactions. This results in a very tough material, with the highest impact strength of any thermoplastic presently made. UHMWPE is odorless, tasteless, and nontoxic.
Emulsion polymerizationEmulsion polymerization is a type of radical polymerization that usually starts with an emulsion incorporating water, monomer, and surfactant. The most common type of emulsion polymerization is an oil-in-water emulsion, in which droplets of monomer (the oil) are emulsified (with surfactants) in a continuous phase of water. Water-soluble polymers, such as certain polyvinyl alcohols or hydroxyethyl celluloses, can also be used to act as emulsifiers/stabilizers. The name "emulsion polymerization" is a misnomer that arises from a historical misconception.
Ethylene glycolEthylene glycol (IUPAC name: ethane-1,2-diol) is an organic compound (a vicinal diol) with the formula . It is mainly used for two purposes, as a raw material in the manufacture of polyester fibers and for antifreeze formulations. It is an odorless, colorless, flammable, viscous liquid. Ethylene glycol has a sweet taste, but it is toxic in high concentrations. This molecule has been observed in outer space. Ethylene glycol is produced from ethylene (ethene), via the intermediate ethylene oxide.
