Plasticizer(增塑剂).ppt

Plasticizer Outline Introduction Historical development Mechanism of plasticization Classification of plasticizer Performance of plasticizer Plasticizer efficiency Plasticizer market Introduction A substance or material incorporated in a material (usually a plastic or an elastomer) to increase its flexibility, workability, or distensibility(膨胀性). In 2003, the worldwide market for plasticizers was more than 4.6 million metric tonnes(10 billion pounds), with approximately 90% applied as plasticizers for PVC. Introduction Introduction Historical development In 1868, use of camphor in nitrocellulose by the Hyatt brothers In the early 1940s, Gresham’s patented use of DOP (di-2-ethylhexyl phthalate) in PVC (DEHP) Until the late1970s, use of DOP prevailed as the preferred general-purpose plasticizer for PVC Recently, 70 different plasticizers available, about 80% of the worldwide consumption is comprised of three plasticizers, di-2-ethylhexyl phthalate (DOP),diisononyl phthalate (DINP), and diisodecyl phthalate (DIDP). Mechanism of plasticization Effect of plasticizers on thermal mechanical deformation of Rigid polymeric chains Lowering the brittle-tough transition or brittleness temperature and Tg and extending the temperature range for their rubbery or viscoelastic state behavior Decreasing the melting viscosity Mechanism of plasticization Lubricating theory of plasticization Gel theory Free volume Lubricating Theory the plasticizer molecules diffuse into the polymer and weaken the polymer-polymer interactions the plasticizer molecules act as shields to reduce polymer-polymer interactive forces and prevent the formation of a rigid network. Gel Theory Considering the plasticized polymer to be neither solid nor liquid but an intermediate state, loosely held together by a three-dimensional network of weak secondary bonding forces. These bonding forces acting between plasticizer and polymer are easily overcome by applied external stresses allowing the plasticized