Phenoxy resin

As with most of the aromatic polymers, phenoxy resins color retention, UV resistance, and weatherability are generally poor. They have limited thermal exposure with a rec-onunended operating temperature range from —60 to 80 C ( — 76 to 176 F). Phenoxy resins are resistant to acids and alkalis, have poor solvent resistance (especially in ketones) 

The major use of phenoxies is as a vehicle for coating formulations. They are exceptionally useful in primer applications where drying speed, compatibility with various kinds of top coats, and high adhesive strength are required. Phenoxies ate used in automotive and marine primers as well as in heavy-duty maintenance primers. 

Phenoxy molding compounds are limited to applications requiring service temperatures not in excess of about 80°C (176°F)- Its combination of good impact strength, clarity, and impermeability makes diis resin attractive for molding, including blow molding, of cosmetic, foodstuff, and household-chemical bottles. 

Their main point of difference is that the phenoxies are of much higher molecular weight ( 25 000). The phenoxies are also said to be slightly branched. Like the epoxide resins they are capable of cross-linking via the pendant hydroxyl groups, in this instance by di-isocyanates and other agents. 

The polymer structure bears a clear resemblance to that of the polycarbonate of bis-phenol A and of the polysulphones so that there are a number of similarities between the materials. The greatest difference arises from the substantial aliphatic segment, which enhances chain flexibility and hence leads to comparatively low softening points. This has placed severe restrictions on the value of these materials and they have found difficulty in competing with the more successful polycarbonates. 

The solubility parameter is about 19.2MPa and being amorphous they dissolve in such solvents as tetrahydrofuran, mesityl oxide, diacetone alcohol and dioxane. Since the main chain is composed of stable C—C and C—O—C linkages the polymer is relatively stable to chemical attack, particularly from acids and alkalis. As already mentioned, the pendant hydroxyl groups are reactive and provide a site for cross-linking. 

Dried granules may be injection moulded, blow moulded and extruded without imdue difficulty with melt temperatures of 220-260°C. The moulding shrinkage (0.003-0.004 cm/cm) is very low and a somewhat greater than normal draft may be required in deep draw moulds. 

The resins found some use as coating, structural adhesives and for bottles to contain alkaline solutions but are no longer marketed. 

The glycidyl ether then reacts with the phenate anion  

The synthesis of low-molecular-weight products is usually carried out in bulk. High-molecular-weight products for coatings and laminates are manufactured in solution with solvents such as butanol. Injectionmolding quality material is synthesized in water-soluble solvents and the product is isolated by precipitation in water. 

Because of the secondary hydroxyl groups, phenoxy resins are important primers. In the automobile industry, this primer is first coated as a special 

When the temperature is sufficiently low and the pH is carefully controlled, perfiuorinated olefins can be epoxidized  

Direct oxidation of perfluoroolefins with O2, which can occur explosively, gives too many side products. 

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This type of adhesive is generally useful in the temperature range where the material is either leathery or mbbery, ie, between the glass-transition temperature and the melt temperature. Hot-melt adhesives are based on thermoplastic polymers that may be compounded or uncompounded ethylene—vinyl acetate copolymers, paraffin waxes, polypropylene, phenoxy resins, styrene—butadiene copolymers, ethylene—ethyl acrylate copolymers, and low, and low density polypropylene are used in the compounded state polyesters, polyamides, and polyurethanes are used in the mosdy uncompounded state. 

Polymer Blends. The miscibility of poly(ethylene oxide) with a number of other polymers has been studied, eg, with poly (methyl methacrylate) (18—23), poly(vinyl acetate) (24—27), polyvinylpyrroHdinone (28), nylon (29), poly(vinyl alcohol) (30), phenoxy resins (31), cellulose (32), cellulose ethers (33), poly(vinyl chloride) (34), poly(lactic acid) (35), poly(hydroxybutyrate) (36), poly(acryhc acid) (37), polypropylene (38), and polyethylene (39). 

Adhesives. High concentration (>10%) solutions of poly(ethylene oxide) exhibit wet tack properties that are used in several adhesive appHcations. The tackiness disappears when the polymer dries and this property can be successfully utilized in appHcations that require adhesion only in moist conditions. PEO is also known to form solution complexes with several phenoHc and phenoxy resins. Solution blends of PEO and phenoxy resins are known to exhibit synergistic effects, leading to high adhesion strength on aluminum surfaces. Adhesive formulations are available from the manufacturers. 

Finally mention may be made of the phenoxy resins. These do not contain the carbonate group but are otherwise similar in structure, and to some extent in properties, to the bis-phenol A polycarbonate. They are dealt with in detail in Chapter 21. 

The so-called phenoxy resins were a development of epoxide resin technology which had hitherto been used exclusively in the thermosetting resin field (see Chapter 26). As with the most important epoxide resins they are prepared by reacting bis-phenol A with epichlorohydrin to give the following structure (Figure 21.9) ... 

Crosslinked polymers were denser than the thermoplastic. The densities of the polymers increased proportional to the number of crosslinks ( Mc ) as shown by the two straight lines in Fig. 5.1. The volume occupied by the polymer was reduced by 0.008 nm3 for each junction introduced in the network. The change of volume was deduced from the slope in Fig. 5.1. Likewise, small voids close to the ends of the molecular chains may well be responsible for the lower density of the Phenoxy resin (g = 1.1807 Mgm-3) as compared to polymer E. 

Even in solution the relative rigidity of the polymer support can play a significant role in the reactivity of attached functional groups. Contrasting studies conducted with chloromethylated derivatives of poly(arylene ether sulfone) (Tg 175°C), phenoxy resin (Tg= 65°C) and polystyrene (Tg= 105°C) allow evaluation of chain rigidity effects. We have shown that the rates of quaternization of chloromethylated poly(arylene ether sulfones) and phenoxy resin deviate from the anticipated second order process at... 

Since poly(oxy-2,6-dimethy1-1,4-phenylene) has exhibited a high tendency to undergo cleavage, rearrangements and to crosslink in the presence of electrophilic reagents,21 our attention has been focused on modification of poly(arylene ether sulfone), 1, and phenoxy resin,4 The active sites in these polymers are the 3-positions of the bisphenol-A repeating units. We will report the extent of... 

Correct IUPAC nomenclature poly(oxy-2,6-dimethyl-l,4-pheylene), PPO, poly(oxy-l,4-phenylenesulfonyl-l, 4 -phenyleneoxy-l",4 phenylene (1 -methylethylidene)-l , 4" -phenylene), poly(arylene ether sulfone), and poly(oxy-(2-hydroxytrimethylene) oxy-l,4-phenylene(l -methylethylidene)-l, 4 -phenylene), phenoxy resin. 

Phenoxy herbicides, 10 520 Phenoxypropionic acid herbicides, 13 314 Phenoxy resins, 10 6, 364-365 Phentermine, 3 91... 

Phenoxy resin Improve impact strength and heat distortion temperature... 

Phenoxy resins can also be used for the modification of PET and PBT. Phe-noxy resins such as Paphen PKFE (Inchem Corporation) are polyhydroxyether materials with pendant hydroxyl groups that can react with the PET. Paphen phenoxy resins are reactive modifiers that can modify and upgrade brittle polymers. Such resins contain 6 % of secondary hydroxyl groups. The latter serve as reactive sites for reaction with polyesters, polyamides, polycarbonates, epoxies and phenolics. 

High molecular weight thermoplastics called phenoxy resins are formed by the hydrolysis of the epoxy resins so that no epoxy groups are present. These transparent resins can be further reacted, forming cross-linked material through reaction of the hydroxyl pendant groups with diisocyanates or cyclic anhydrides. 

Crystallization behavior in miscible blends containing crystallizable components has been extensively studied [174-180]. Generally, when a crystallizable component is mixed with an amorphous component its melting temperature goes down and its crystallinity lowers. The same trend has been reported for blends with intercomponent hydrogen bonding such as PCL/STVPh [181], PCL/poly(hydroxyl ether of bisphenol A) [182] and phenoxy resin/PEO [183]. 

A related material, phenoxy resin, is a thermoplastic composed of the following repeating unit ... 

Phenoxy resins are high-molecular-weight, amorphous, linear pseudoepoxy resins that do not contain epoxy groups. Because of the presence of hydroxyl... 

Phenoxy resins may be extruded, injection-molded, and blow-molded to produce pipe, sporting goods, containers, and appliance housings. Since phenoxy resins are soluble in methyl ethyl ketone, they have been used as adhesives and cross-linkable protective coatings. 

An interesting approach to maleimide-terminated phenoxy resin has recently has described (42). para-Maleimidobenzoic acid was reacted with diglyci-dylbisphenol-A epoxy resin in the presence of catalyst to provide the bismale-imide of Fig. 13. Instead of diglycidyl bisphenol-A, linear epoxy resin pre-polymers can be used in this reaction to form a maleimide terminated phenoxy resin. Another suitable functionalized monomaleimide is m- or p- N-(hydroxyphenyl) maleimide which is synthesized from maleic anhydride and m-aminophenol in DMF as a solvent at 70 °C. The purified hydroxyphenyl maleimide was reacted with epoxy resin to form novel BMIs as outlined in Fig. 14. The new BMI and phenoxy oligomers polymerize at temperatures of 200-220 °C, but the cure temperatures can be significantly lowered when catalysts such as imidazoles or triphenylphosphine are added. The cured homopolymers show Tg of 140 and 230 °C for the n = 2 and the n = 1 polymer, respectively(43). 

Fig, 13. Maleimide-terminated phenoxy resin obtained from 4-maleimidobenzoic acid (42)... 

Epichlorohydrin is a major raw material for epoxy and phenoxy resins, and is used in the manufacture of glycerine, in curing propylene-based rubbers, as a solvent for cellulose esters and ethers, and in resins with high wet-strength for the paper industry (Lewis, 1993). 

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