Other Polymers

Other Polymers.—A polymeric gel, in which salicylaldehyde and lysine residues are capable of forming an internal aldimine, may be prepared by copolymerization of iV-tf-5-methacryloylaminosalicylidene-A-e-methyacryloyl-(iS )-lysinatocopper(ii) with acrylamide and AW -methylenebisacrylamide in water with subsequent removal of copper(n) ions. The equilibrium constants for internal aldimine formation are 30-100-fold higher than that for a suitable model. The er-amino group of the L-lysine residue in the gel acts as nucleophilic catalyst in the reaction of the salicylaldehyde residue of the gel with semicarbazide, with a rate enhancement of 

Amino-acid esters may be stereoselectively hydrolysed at pH 8 by polymeric catalysts containing amino-acid derivatives chelated to Cu or Ni attached to matrices of cross-linked polystyrene or polyacrylamide. Selectivity results from amino-acid ester co-ordination rather than from the affinity of the catalyst for the hydrolysis product.  

Poly(vinylbenzene) or polystyrene containing mercapto groups may have the degree of proximity assessed by iodine oxidation to disulphide.  

Quaternized poly(dimethylaminoethyl methacrylate) catalyses the esterification of acrylic acid by epichlorohydrin.  

Some other polymers such as aromatic and aliphatic hydrocarbon resins, high MW alkylated amino resins, polyvinyl ethers and polyvinyl butyrals are utilized for the purpose of enhancing leveling. They are not marketed as leveling agents but are used in specialty products. 

TPS can also be blended with other polymers such as polyolefins [115]. In this sort of blend, a compatibiliser such as an ethylene-maleic anhydride copolymer can be used in order to make the hydroxyl starch groups and anhydride copolymer groups react, resulting in ester bonds. This sort of esterification helps to compatibilise the starch (hydrophilic) with polyolefins (lipophilic). 

Other studies have been performed on polyamide/high amylose starch and acrylic copoly- mers/high amylose starch systems [55,116-118]. 

The noncompliance of these products with the international norms of biodegradability and compostability, howevei prevented significant market growth in Western countries. 

TPS and cellulose derivative systems have also been reported [98, 112, 119, 120], particularly with cellulose acetate and butyrate in the presence of glycerine and epoxidised soybean oil [119]. 

These materials are especially suitable for injection moulding technology and have been industrially used for compostable cutlery. 

Regioisomerism is also exhibited by other polymers, including polyvinylidene fluoride, polyvinylidene chloride [8-11], polydienes and polyvinyl acetate [12,13]. Head-to-tail and tail-to-tail sequences have been determined for polyvinylidene chloride [8-12] and polyvinyl acetate [12,13]. 

Dall Asta, G. Mazzanti and F. Ciampelli, Kolloid Zeitschrift, 1962, 

Tanaka and K. Hatada, Journal of Polymer Science Polymer Chemistry 

Grant and E.G. Paul, Journal of the American Chemical Society, 1964, 

Journal of Polymer Science Part A General Papers, 1964,2,4, 

Polymeric collagen peptides should be somewhat substantive to hair because they contain multiple ionic and polar sites for bonding, in addition to offering large molecular surfaces with many sites for Van der Waals bonding. Methionine, tyrosine [46], and tryptophan [47] are monomeric species of proteins, and they have been shown to sorb onto hair from aqueous solution. Collagen-derived polypeptides, or polymers of amino acids, have also been shown to have an affinity for hair [48-50], and one would predict that they should be more substantive to hair than their monomers. 

The desorptive action of surfactants and salts on polypeptides already sorbed to hair has not been examined as fully as for polymer JR. On the basis of theory, one would not expect collagen-derived polypeptides to be as substantive to hair as a high-charge-density cationic polymer. 

Some neutral and anionic polymers used in hair products. 

Copolymer of methyl vinyl ether and ethyl ester of maleic anhydride 

Steam-solvent distillation using diethyl ether has been used to remove and analyse for odour and taint from additives in food packaging films. Another technique that has been used is vacuum/thermal extraction. This procedure has been applied to polyamides and fluorocarbon polymers. The procedure is used for the direct isolation or release of volatile components from a polymeric matrix and may involve the combined use of vacuum and heat, as for example in the mass spectrometer direct insertion probe or during dry vacuum distillation. Alternatively, the volatiles may be swept from the heated sample by a flow of inert gas for concentration by freeze trapping and/or collection on to a solid adsorbent prior to thermal or solvent desorption for GC or mass spectrometric (MS) examination. 

Polyethylene oxide reactions were thoroughly investigated by Fisher etal. [376]. The G values for crosslinking, chain scission and volatile formation for electron irradiation at 14°C and a dose rate of 600 Mrad h 1 are given in Table 27. To account for these values, the mechanism proposed was 

Polyethyleneterephthalate crosslinks or degrades under 7 or electron irradiation [378]. A dose rate dependence of the chain-scission yield has been reported and discussed [379, 380]. G values for gas formation are C02, 0.17 CO, 0.11 H2, 0.015 and CH4, 0.003 [379]. 

Polysulphone prepared from 2,2-bis(4-hydroxyphenyl)propane and 4,4-dichlorodiphenylsulphone is particularly stable to electron irradiation [381]. Retention of flexural strength and modulus are retained 

The radiolysis of polycarbonate presents similarities to that of aromatic polysulphones [383, 384]. It undergoes main-chain scission with a G value of 0.09 under vacuum and 0.14 in an oxygen atmosphere. The gases evolved are carbon monoxide, carbon dioxide, hydrogen and methane. The G values are, respectively, 3.6 x 10 1,1.9 x 10 1, 1.3 x 10 2 and 1.3 x 10-3. Since G(CO + C02) is larger than the G value for chain scission, cage recombination of the macroradicals is supposed to occur. 

BCC has predicted that sales of PET, HDPE, the polyamides and polystyrenes will all grow reasonably well in North America over the period 2003-2008, whereas demand for PVC, the polyurethanes and ABS is expected to be modest and polystyrene demand will grow at about 3 to 4% a year. TPE growth has been predicted at over 6%/y, reaching 2.15 M tonnes/y by 2006. 

The process of replacing glass and aluminiiun containers by PET in North America is thought by some to have almost reached completion, and consequently PET might not be able to sustain 

There is increasing competition for the markets currently held by high performance polymers, because of competition from cheaper commodity thermoplastics that have had their performance enhanced by additives. 

Source D. Debier, Paper 8, Proc. 9 Addcon World Conference on Additives and Modifiers, Vienna, Austria, October 2003, Rapra Technology Ltd.  

Demand for polycarbonate in particular is growing mainly because of its usage in DVDs. By 2005, Bayer estimates that optical discs will account for one-third of production, i.e., 800,000 tonnes of polycarbonate out of a global consumption of 2.4 M toimes. Much of the demand is coming from China, where a growth rate of 16.7% in the optical storage market has been predicted by Plastics and Chemicals Intelligence Asia. 

The Raman spectra of doped states of polyaniline [99], poly(/ -phenylenevinylene) [75, 100-102], and polythiophene [72, 73] have been also analyzed on the basis of the data of charged oligomers (charged oligomer approach). The detected self-localized excitations are summarized in Table 4-5. Some important conclusions can be drawn from these Raman studies. 

HCl-doped emeraldine base form is called emeraldine acid form or 2S form. 

Only polarons are detected for p-type doping. The Raman spectra of the polymers doped with acceptors do not show large changes with various excitation wavelengths [72, 73, 75]. The polymer-chain structures of p-type-doped polymers are more homogeneous, and more regular arrays of polarons are formed. 

Schulz et al. [497] described a series of poly(oxadiazoles) for potential LED applications. Some of their structures have been depicted earlier in Fig. 12-21. These were prepared by a one-step polycondensation of the aromatic dicarboxylic acids with hydrazine hydrate in polyphosphoric acid, which acted as a solvent as well as dehydration agent. 

El-Shekeil et al. [680] recently described synthesis of novel poly(azomethine) CPs which were claimed to be crystalline as well as conductive. These were synthesized by the polycondensation ofp-phenylenediamine and 2-nitro-p-phenylenediamine with tereph alaldehyde and p-diacetylbenzene. The polymers with -NO2 and other polar functional groups were found to be more soluble in common organic solvents. 

Gonzdlez-Tejera et al. [681] recently reported electropolymerization of poly(furan)-/perchlorate from monomer solutions in aprotic media in which dopant concentrations were lower than monomer concentrations. The CP films were claimed to be conductive. Belloncle et al. [682] claimed production of conductive, electroactive CP films from electropolymerization, in tetrafluoroborate/methylene chloride, of several crown ethers such as bis-binaphtho-22-crown-6 and binaphtho-20-crown-6. 

Pandey and Prakash [683] studied the electropolymerization of indole inperchlorate/-dichloromethane in detail, by potential sweep (-0.2 to 1.0 V vs. Ag ), potentiostatic (1.0 V vs. Ag ) and galvanostatic (0.2 to 0.3 mA/cm ) methods. Conductivities in the region of 1 S/cm were obtained. A Zn/poly(indole) secondary battery was constructed and tested. 

Talbi and Billaud [684] also studied electropolymerization of indole and 5-cyano-indole in standard media (perchlorate/acetonitrile). The electrochemistry of these electroactive films was reported. 

FIGURE 21.27 Polymer synthesis involving opening of strained rings. 

What would be the repeating unit of the polymer prepared from each of the following pairs of compounds  

Step-growth polymers involve the reaction of a bifunctional monomer, or two bifunctional monomers, to give a polymer. High conversions in the coupling reaction are critical to preparing materials with a useful molecular weight. 

Polyesters and polycarbonates are prepared by esterification or transesterification. Polyamides are prepared from diacids and diamines, usually under acidic conditions. 

The high melting point of polyamides derives from interchain hydrogen bonding. Polyurethanes are prepared from diisocyanates and diols. 

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Krilium The trade name of a soil conditioner. The solid form of Krilium has as active in-gredienl a copolymer of about equal molar proportions of vinyl ethanoate and the partial methyl ester of maleic acid. It may be formulated with lime, bentonite, etc. In aqueous form, Krilium contains a copolymer of about equal molar proportions of isobutene and ammonium maleamate. Other polymers are also used. 

McjC = CHCOCH3. Colourless liquid b.p. 129"C, with a strong peppermint-like odour. Prepared by distilling diacetone alcohol in the presence of a trace of iodine. Converted to phorone by heating in propanone with dehydrating agents such as sulphuric acid. It is a solvent For cellulose acetate and ethyl-cellulose and other polymers. 

Other polymers, such as poly methacrylates, have been studied, as well as esters of naturally occurring polysaccharides. References can be found in the literature cited in the list of further reading. 

Synthetic Rubbers. Synthetic rubbers are polymers with rubberlike characteristics that are prepared from dienes or olefins. Rubbers with special properties can also be prepared from other polymers, such as polyacrylates, fiuorinated hydrocarbons, and polyurethanes. 

Whether the beads representing subchains are imbedded in an array of small molecules or one of other polymer chains changes the friction factor in Eq. (2.47), but otherwise makes no difference in the model. This excludes chain entanglement effects and limits applicability to M < M., the threshold molecular weight for entanglements. 

Polyethylene. The crystal structure of this polymer is essentially the same as those of linear alkanes containing 20-40 carbon atoms, and the values of Tjj and AHf j are what would be expected on the basis of an extrapolation from data on the alkanes. Since there are no chain substituents or intermolecular forces other than London forces in polyethylene, we shall compare other polymers to it as a reference substance. 

The greatest concern with PVC is as a contaminant in other polymers being recycled, particularly PET. Approximately 12 million pounds of PVC was recycled in 1993, about half from packagiag (25). AppHcations for recycled PVC iaclude as an inner layer sandwiched between two virgin PVC layers in pipe and sheet for bHster packagiag and other packagiag appHcations. 

Conductivities of polymers of technological interest such as polypyrrole and polythiophene are typically 1000 cm in the doped state, and the conductivity can be tuned by reversibly doping and undoping the polymer. Derivatives of these and other polymers have achieved even higher conductivities. 

Most of the polymer s characteristics stem from its molecular stmcture, which like POE, promotes solubiUty in a variety of solvents in addition to water. It exhibits Newtonian rheology and is mechanically stable relative to other thermoplastics. It also forms miscible blends with a variety of other polymers. The water solubiUty and hot meltable characteristics promote adhesion in a number of appHcations. PEOX has been observed to promote adhesion comparable with PVP and PVA on aluminum foil, cellophane, nylon, poly(methyl methacrylate), and poly(ethylene terephthalate), and in composite systems improved tensile strength and Izod impact properties have been noted. 

Acryhc esters dimerize to give the 2-methylene glutaric acid esters catalyzed by tertiary organic phosphines (37) or organic phosphorous triamides, phosphonous diamides, or phosphinous amides (38). Yields of 75—80% dimer, together with 15—20% trimer, are obtained. Reaction conditions can be varied to obtain high yields of trimer, tetramer, and other polymers. 

With the exception of glass fiber, asbestos (qv), and the specialty metallic and ceramic fibers, textile fibers are a class of soHd organic polymers distinguishable from other polymers by their physical properties and characteristic geometric dimensions (see Glass Refractory fibers). The physical properties of textile fibers, and indeed of all materials, are a reflection of molecular stmcture and intermolecular organization. The abiUty of certain polymers to form fibers can be traced to several stmctural features at different levels of organization rather than to any one particular molecular property. 

The film tube is collapsed within a V-shaped frame of rollers and is nipped at the end of the frame to trap the air within the bubble. The nip roUs also draw the film away from the die. The draw rate is controlled to balance the physical properties with the transverse properties achieved by the blow draw ratio. The tube may be wound as such or may be sHt and wound as a single-film layer onto one or more roUs. The tube may also be direcdy processed into bags. The blown film method is used principally to produce polyethylene film. It has occasionally been used for polypropylene, poly(ethylene terephthalate), vinyls, nylon, and other polymers. 

BiaxiaHy oriented films have excellent tensile strength properties and good tear and impact properties. They are especially well regarded for their brilliance and clarity. Essentially all poly(ethylene terephthalate) film is biaxiaHy oriented, and more than 80% of polypropylene film is biaxiaHy oriented. Polystyrene film is oriented, and a lesser amount of polyethylene, polyamide, poly(vinyl chloride), and other polymers are so processed. Some of the specialty films, like polyimides (qv), are also oriented. 

The dissipation factor (the ratio of the energy dissipated to the energy stored per cycle) is affected by the frequency, temperature, crystallinity, and void content of the fabricated stmcture. At certain temperatures and frequencies, the crystalline and amorphous regions become resonant. Because of the molecular vibrations, appHed electrical energy is lost by internal friction within the polymer which results in an increase in the dissipation factor. The dissipation factor peaks for these resins correspond to well-defined transitions, but the magnitude of the variation is minor as compared to other polymers. The low temperature transition at —97° C causes the only meaningful dissipation factor peak. The dissipation factor has a maximum of 10 —10 Hz at RT at high crystallinity (93%) the peak at 10 —10 Hz is absent. 

Chemical Properties. A combination of excellent chemical and mechanical properties at elevated temperatures result in high performance service in the chemical processing industry. Teflon PEA resins have been exposed to a variety of organic and inorganic compounds commonly encountered in chemical service (26). They are not attacked by inorganic acids, bases, halogens, metal salt solutions, organic acids, and anhydrides. Aromatic and ahphatic hydrocarbons, alcohols, aldehydes, ketones, ethers, amines, esters, chlorinated compounds, and other polymer solvents have Httle effect. However, like other perfluorinated polymers,they react with alkah metals and elemental fluorine. 

Unlike most crystalline polymers, PVDF exhibits thermodynamic compatibiUty with other polymers (133). Blends of PVDF and poly(methyl methacrylate) (PMMA) are compatible over a wide range of blend composition (134,135). SoHd-state nmr studies showed that isotactic PMMA is more miscible with PVDF than atactic and syndiotactic PMMA (136). MiscibiUty of PVDF and poly(alkyl acrylates) depends on a specific interaction between PVDF and oxygen within the acrylate and the effect of this interaction is diminished as the hydrocarbon content of the ester is increased (137). Strong dipolar interactions are important to achieve miscibility with poly(vinyhdene fluoride) (138). PVDF blends are the object of many papers and patents specific blends of PVDF and acryflc copolymers have seen large commercial use. 

Uses. Neopentyl glycol is used extensively as a chemical intermediate in the manufacture of polyester resins (see Alkyd resins), polyurethane polyols (see Urethane polymers), synthetic lubricants, polymeric plasticizers (qv), and other polymers. It imparts a combination of desirable properties to properly formulated esterification products, including low color, good weathering and chemical resistance, and improved thermal and hydrolytic stabiUty. 

Adding amines to coating compounds containing other polymers of hydantoin derivatives permits thermal curing of the coating compounds, which are useful as electrical insulators of wires under a broad range of conditions without loss of coating flexibiUty (101). 

Solubility Parameter. CompatibiHty between hydrocarbon resins and other components in an appHcation can be estimated by the Hildebrand solubiHty parameter (2). In order for materials to be mutually soluble, the free energy of mixing must be negative (3). The solubiHty of a hydrocarbon resin with other polymers or components in a system can be approximated by the similarities in the solubiHty parameters of the resin and the other materials. Tme solubiHty parameters are only available for simple compounds and solvents. However, parameters for more complex materials can be approximated by relative solubiHty comparisons with substances of known solubiHty parameter. 

Acetylene is condensed with carbonyl compounds to give a wide variety of products, some of which are the substrates for the preparation of families of derivatives. The most commercially significant reaction is the condensation of acetylene with formaldehyde. The reaction does not proceed well with base catalysis which works well with other carbonyl compounds and it was discovered by Reppe (33) that acetylene under pressure (304 kPa (3 atm), or above) reacts smoothly with formaldehyde at 100°C in the presence of a copper acetyUde complex catalyst. The reaction can be controlled to give either propargyl alcohol or butynediol (see Acetylene-DERIVED chemicals). 2-Butyne-l,4-diol, its hydroxyethyl ethers, and propargyl alcohol are used as corrosion inhibitors. 2,3-Dibromo-2-butene-l,4-diol is used as a flame retardant in polyurethane and other polymer systems (see Bromine compounds Elame retardants). 

Other Polymers. Besides polycarbonates, poly(methyl methacrylate)s, cycfic polyolefins, and uv-curable cross-linked polymers, a host of other polymers have been examined for their suitabiUty as substrate materials for optical data storage, preferably compact disks, in the last years. These polymers have not gained commercial importance polystyrene (PS), poly(vinyl chloride) (PVC), cellulose acetobutyrate (CAB), bis(diallylpolycarbonate) (BDPC), poly(ethylene terephthalate) (PET), styrene—acrylonitrile copolymers (SAN), poly(vinyl acetate) (PVAC), and for substrates with high resistance to heat softening, polysulfones (PSU) and polyimides (PI). 

Electronic Properties. What distinguishes polysdanes from virtually ad. other polymers is their backbone CJ-conjugation. This leads to strong electronic absorption in the near-uv from a O —O transition. For most homo- and copolymers the absorption maximum (/-j ) hes between 300 and 400... 

M. Zeldin, K. J. Wynne, and H. R. AUcock, eds.. Inorganic and Organometallic Poljmers, ACS Symposium Series, Vol. 360, American Chemical Society, Washington, D.C., 1988 regarding poIy(phosphazenes), poly(silanes), and other polymers. 

The first successhil use of lithium metal for the preparation of a i7j -l,4-polyisoprene was aimounced in 1955 (50) however, lithium metal catalysis was quickly phased out in favor of hydrocarbon soluble organ olithium compounds. These initiators provide a homogeneous system with predictable results. Organ olithium initiators are used commercially in the production of i7j -l,4-polyisoprene, isoprene block polymers, and several other polymers. 

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