ABSTRACT
The polyethylene products known as low density polyethylene (LDPE) resins are produced exclusively by high pressure free radical polymerization. The chemistry involved in their production is deceptively simple, requiring little more than an appropriate source of free radicals and conditions of high temperature and pressure. The free radicals initiate the polymerization process when the monomers have been forced into close proximity by high pressure. Termination of chain growth occurs when the free radical on a growing chain is transferred to another chain or is quenched by another radical. In practice, numerous competing side reactions occur that result in branching and premature chain termination. The nature of the product is controlled by the initiator concentration, temperature, pressure, availability of vinyl comonomers, and the presence of chain transfer agents.
