"Polyesters, Thermoplastic". In: Encyclopedia of Polymer ... .fr
Although he studied a wide range of polyesters, made both from aliphatic ... highly crystalline, it had a high rate of crystallization, so that parts could be molded in ...
POLYESTERS, THERMOPLASTIC Introduction Polyesters enter our lives in a most ubiquitous manner as textiles, carpets, tire cords, medical accessories, seat belts, automotive and electronic items, photographic film, magnetic tape for audio and video recording, packaging materials, bottles, and so on. Their utility is illustrated by the vast range of their applications. This article describes the properties, synthesis, manufacture, and raw materials for the two most widely used thermoplastic polyesters: poly(ethylene terephthalate) (PET) [25038-59-9] and poly(butylene terephthalate) (PBT) [26062-94-2]. In order of volume, PET comes first by virtue of its enormous market tonnage in polyester fibers and films, as well as the resin for blow-molded bottles, containers, and food packaging. Polyesters are linear polymeric molecules containing in-chain ester groups, formally derived by condensation of a diacid with a diol. The earliest commercial polyesters were the alkyd resins (qv), nonlinear polymers developed for surface coatings shortly after World War I. It was not until the 1930s that the classic studies of Carothers examined main-chain polyesters in a rigorous and systematic fashion (1). Although he studied a wide range of polyesters, made both from aliphatic diacids and diols (AA-BB) type and from ω-hydroxyacids (ABAB type), for various reasons, Carothers did not pursue polyesters derived from aromatic diacids and alkylene diols. All his aliphatic polymers were low melting (
plastic elastomeric materials are a significant and growing part of the total ..... of the two-phase domain structure in the melt and the extra energy required to ..... seals (applied to hold the aggregate in place when a road is resurfaced); .... M.
technology to companies in Japan and Western Europe, and installed fiber plants ... As the technology developed, PET fibers penetrated into a number of end-.
define enzymatic polymerization as âchemical polymer synthesis in vitro (in test tubes) via nonbiosynthetic .... Fig. 2. Enzymatic synthesis of celluloseâxylan hybrid polymer. .... The polymerization of ethyl glycolate using PEG-modified esterase
electrical insulators because they have substantially constant modulus between the glass ..... It seems that the use of solar energy to heat water in some tropical ...
tity has a two-electron, three-center-bound pentacoordinated carbon; .... monomers using UVâvis spectroscopy and are discussed more later in this article. ..... are enthalpy driven; the entropy loss of about â120 J/mol/K related to the loss of.
yield criteria, these being methods to quantify the yield stress as a function of ..... the maximum distortional energy criterion or the octahedral stress theory) (25).
A graft copolymer with one branch can be considered as a miktoarm ...... stress at break, toughness and yielding stress for poly(butyl ... graft copolymers were found to increase, whereas yield elongation decreased as ... Stress at break, MPa. Y oung
and indicates the amount of energy loss in the material as dissipated heat. This ... approaches are used: (1) forced frequency, where the signal is applied at a set.
porous catalysts, vibration dampers, membranes, colloidal glasses). They are ... R. B. Bird, R. Armstrong, and O. Hassager, Dynamics of Polymeric Liquids, Vol.
Once formed, radicals undergo two basic types of reactions: propagation re- actions and termination ...... Economic Aspects. The principal worldwide ... Kroschwitz, eds., Encyclopedia of Polymer Science and Engineering, 2nd ed., Vol. 13,.
two substances is small, dissolution will occur since the heat of mixing will be ..... can be helped through the adjustment of comonomer composition as well as .... A valve is placed in the bottom of the reactor to release polymerized material to ...
weight distribution is measured by gel-permeation chromatography (gpc). Short-Chain ..... Vapor from the flash step is condensed, cooled, and returned.
Bismuth oxychloride pigment is the closest to natural pearl but is fragile and has relatively poor ..... Molybdates and vanadates are often used as catalysts for.
include the fact that it is a liquid polymer, and so it does not require a solvent ..... by the APA-Engineered Wood Association as the APA-Engineered Wood ...
raised by porosity and decreased by surface oxygen or adsorbed organics. ...... nents and in containers and pipes for combustible liquids such as gasoline. The.
relatively weak forces (van der Waals, ionic, solvation, donor/acceptor), ..... analogous to those used to derive equations 4â6 (97), and (2) high surface mo-.
These polymers are thus often referred to in the polymer literature as .... sulfone is made in chlorobenzene as solvent, with (2.2.2)cryptand as catalyst (9).
materials to produce modified or advanced epoxy resins, which may be .... Cured LERs give tight cross-linked networks having good strength and hardness but have .... hydroxide solution (75 parts by weight) is introduced into a reactor equipped with .
terification process and the polycarbonate product so formed (11). ..... have been invoked as mechanisms for energy absorption, providing .... bonate exhibits excellent thermal stability, especially in the absence of oxygen ... Visible light transmis
to provide low extensibility and high shear strength. Addition of glass or .... In theory, shear is strictly a bulk property of the adhesive that is not affected by surface ...
types of polymers. The transport properties of glassy and rubbery polymers are related to their ... Encyclopedia of Polymer Science and Technology. Copyright John ...... J. R. Fried, M. Sadat-Akhavi, and J. E. Mark, J. Membr. Sci. 149(1), 115 ...
high pressure steam in an autoclave. Other applications, such as wire insulation and jacketing, are subjected to fast, continuous, high pressure steam vulcaniza-.
The polymers known as polyurethanes include materials that incorporate ... and excellent processibility, but limited thermal stability (owing to their thermo- plasticity). Thermoset ... propylene oxides provided the foam manufacturers with a broad ch
