Ethylene derivatives polymers

Ch1orocarhony1trime11itic acid 1,2-anhydride [1204-28-0] (9), is used in the preparation of esters and amide—imide polymers. TriaHyl trimellitate [2694-54-4] (10) is used as a cross-linking or co-curing agent for ethylene-derived mbbers and plastics. 

Synthetic rubber(s), 1 693, 21 761. See Ethylene-propylene polymers. See also Butyl rubber acetylene-derived sources, 1 228 synthesis of first butyl rubber after disruption of natural rubber supply in WW II, 4 433... 

Patri, M., Hande, V. R., Phadnis, S. and Deb, P. C. 2004. Radiation-grafted solid polymer electrolyte membrane Studies of fluorinated ethylene propylene (PEP) copolymer-g-acrylic acid grafted membranes and their sulfonated derivatives. Polymers for Advanced Technologies 15 485-489. 

Several procedures exists for calculating the heats of polymerization for various monomers but they are not very important. It is still more useful to consider the experimentally measured values as the best basis both for theoretical studies and for practical calculations. For ethylene derivatives, the value of — AHlc (from liquid monomer to amorphous solid polymer) ranges from 33.5 kJ mol-1 for a-methylstyrene, through ca. 96 kJ mol-1 for vinyl chloride, to 174 kJ mol-1 for tetrafluoroethylene. 

Many ethylene derivatives having the general structure CH2=CHZ are also used as monomers for polymerization. The identity of Z affects the physical properties of the resulting polymer, making some polymers more suitable for one consumer product (e.g., plastic bags or food wrap) than another (e.g., soft drink bottles or compact discs). Polymerization of CH2=CHZ usually affords polymers with the Z groups on every other carbon atom in the chain. Table 15.2 lists some common monomers and polymers prepared industrially. 

For the change, monomer (liquid) to polymer (crystalline), the A8 p values are relatively constant for the ethylene derivatives shown, and the general conclusion drawn from this is that whereas substitution has a considerable effect on AHp it has little effect on AS... 

Besides the addition of halogens and hydrohalogens across the double bond just covered, there are many other reagents that will react similarly with unsaturated polymers by free radical, ionic, or radical-ion mechanisms. Of prime importance is the addition of ethylene derivatives to polydienes. One of the earliest reactions of natural rubber to be studied in detail was the combination with maleic anhydride (Cunneen and Porter, 1965). Depending on the reaction conditions and the presence or absence of free radical initiators, one or more of four basic reactions may take place, with the products shown (the arrows indicate where the addition has taken place and the new bonds formed). 

Ditactic polymers possess two stereoisomeric centers per constitutional monomeric unit, and tritactic polymers possess three. Ditactic polymers may be formed by the polymerization of 1,2-disubstituted ethylene derivatives, as, for example, with pentene-2 ... 

Nokwequ, G. M. and Bariyanga, J. Synthesis, characterization and biodegradability of a water-soluble poly(ethylene oxide) derivative polymer bearing carboxylic acid side chain function.. Bioact. Compat. Polym., 15, 503, 2000. 

Chem. Descrip. Syn. wax ethylene-derived hydrocarbon polymer CAS 8002-74-2 EINECS/ELINCS 232-315-6... 

An important group of enzymatically derived polymers is polyesters. In nature, they hold the fourth place after the three major biomacromolecules (nucleic acids, proteins, and polysaccharides). Important polyesters are poly(ethylene terephthalate) (PET), poly(butylene succinate) (PBS), poly(e-caprolactone) (poly(e-CL)), and poly(lactic acid) (PLA) (see Fig. 3.40). The former two are industrially produced via polycondensation and the latter two via ROP. Additionally, enzymes can be used to hydrolyze ester bonds, which offers the possibility to recycle commercially used materials, for example, PET [52]. 

In order to improve the enantioselectivity in the AD of aliphatic alkenes, the two dihydroquinidine-derived polymers 275 and 276 were prepared by radical copolymerization of the corresponding monomers with hydroxyethyl methacrylate and ethylene glycol dimethacrylate as crosslinking agent (Scheme 112) [172], These two polymers 275 and 276 exhibited enhanced enantioselectivities (88 and 86% vs 75% with polymer 274) for the dihydroxylation of two aliphatic alkenes, 1-decene and 5-decene compared to those observed... 

Polymer-supported osmium tetroxide j sodium periodate Oxo compds. from ethylene derivs. 

By far the greatest part of PVC production across the world is now made by the suspension process. Vinyl chloride monomer (derived from a reaction between ethylene (derived from oil) and chlorine (derived from common salt) is dispersed in deionised water with the help of small quantities of chemical dispersants and polymerisation initiators (typically peroxide compounds). At moderately raised temperature (50 C) and pressure (0.7 MPa) polymerisation proceeds and the polymer can be removed from the resulting slurry by de-watering and steam stripping the unconverted vinyl chloride monomer. 

Polyethylene is an example of a synthetic polymer. Ethylene, derived from petroleum, is made to react with itself to form polyethylene (or polythene). 

Ethylene derivatives, in which one or more hydrogen atoms have been replaced by other atoms or groups, can also be polymerized. Many of our commercial synthetic polymers are made from such modified ethylene monomers. For example, CH2=CH— is a vinyl group and CH2=CHC1 is vinyl chloride. Vinyl chloride can be polymerized to polyvinyl chloride (PVC). The names, structures, and some uses for several of these polymers are given in Table 19.9... 

Ethylene and its derivatives are the most common monomers for polymers. Write formulas for these ethylene-based polymers ... 

Other Matrices. A large number of other matrices have been employed, including starch (33), cross-linked dextrins (34,35), a vinyl maleimide polymer (36), chitin (37), mannan (38), and insolubilized proteins (39). The number of potential matrices is almost limitless, and most of the matrices used for immobilization of enzymes have potential application in bioselective adsorption. Among these are nylon (40), metal oxides (41), maleic anhydride-ethylene co-polymers (42), and polystyrene derivatives (43). Few of these have been used because of their potential for nonspecific adsorption either by charge, as with the metal oxides, or by hydrophobic interactions (as would be the case with polystyrene). The derivatized matrix must be free of nonspecific adsorption. Proper derivatization can eliminate nonspecific adsorption or, as with cyanogen bromide activation, create nonspecific adsorption in matrices having no prior nonspecific adsorption properties. 

The resulting polymer, polyethylene, consists essentially of a long chain of repeating -CH2-CH2- groups (the structural units) in a typical commercial material n has a value of the order of 1000. Further examples of polymerizations of ethylene derivatives are as follows ... 

---