Iso phthalic acid

Hajek et al. [173] have reported a detailed kinetic study of the solid phase decomposition of the ammonium salts of terephthalic and iso-phthalic acids in an inert-gas fluidized bed (373—473 K). Simultaneous release of both NH3 molecules occurred in the diammonium salts, without dehydration or amide formation. Reactant crystallites maintained their external shape and size during decomposition, the rate obeying the contracting volume equation [eqn. (7), n = 3]. For reaction at 423 K of material having particle sizes 0.25—0.40 mm, the rate coefficients for decompositions of diammonium terephthalate, monoammonium tere-phthalate and diammonium isophthalate were in the ratio 7.4 1.0 134 and values of E (in the same sequence) were 87,108 and 99 kJ mole-1. 

The reaction of the double bond to form crosslinked networks and the chemorheology of these systems are considered later. Different acid and diol starting materials result in polyester resins with superior properties. For example, the use of iso-phthalic acid instead of phthalic anhydride (that produces ortAo-phthalate units) results in improved water resistance of the resins, but at increased cost. 

For example, if a polyester contains two acids and two diols each in equal concentrations of 0.25 moles, its [MI]ab is calculated from L=2, ma=mb=0.25. If the two acid units are terephthalic acid and iso-phthalic acid then they score [MI]a= 6 and 4 respectively and if the diol units are hydroquinone and methyl hydroqui-none, then these score [MI]b=6 and 5 respectively Eq. (2) becomes... 

The dimer synthon formed by the carboxyl group has been used to assemble a variety of supermolecules due to its bidentate character which increases the strength of the interaction. For example, terephthalic acid (8) [39] and iso-phthalic acid (9) [40] form one dimensional tapes. Trimesic acid (2) with its threefold molecular symmetry forms a two dimensional hydrogen bonded sheet [41] and adamantane-l,3,5,7-tetracarboxylic acid (10) with its tetrahedrally disposed carboxy functionality forms a diamondoid network (Fig. 9) [42]. 

A transparent polyamide with good properties is also obtained from iso-phthalic acid in combination with the diamine, V, and lauryl lactam. Ail these glass-clear polyamides compete with polycarbonate, but unlike the latter, are not susceptible to stress corrosion crazing. 

Needles from AcOH.Aq. M.p. 216°. Sol. EtOH. Spar. soL hot HjO. CrOj —> iso-phthalic acid. Heat with lime —> fluorenone. Di-Me eaUr cirot. from EtOH. M.p. 70°. Diamide MW, 2. M.p,... 

According to the results in Table 9 at fixed lactam-12 content, the replacement of fere-phthahc acid by iso-phthalic acid does not influence T12. On the other hand, increasing the lactam-12 content (from 1 to 1.8 mole per repeat imit) results in a decrease of about 10 °C in Tn-... 

In this review of the history of polyarylates, only those products of an aromatic dicarlDoxylic acid (or derivative) and a diphenol (or derivative) will be considered. Structurally similar aromatic polyesters based on p-hydroxybenzoic acid have received considerable interest due to the resultant liquid crystalline behavior of these materials. They, however, will not be covered in this paper. The primary polyarylate discussed herein is leased on Bisphenol A (2,2-bis(4-hydroxyphenyl)propane) and tere/iso-phthalic acids. These monomers are large volume commercial products and are utilized in the primary commercial polyarylates available today. 

In the first half of this chapter, only three components (acetic acid, water, and the entrainer) in the heterogeneous distillation column will be assumed to be present. However, in the production of aromatic acid, acetic acid is used as a solvent in the terephthalic acid or iso-phthalic acid processes. A terephthalic acid, or isophthahe acid slurry in acetic acid solvent, is produced by oxidizing p-xylene (PX) or m-xylene (MX), removing water by evaporation of a stream of mixture with water and acetic acid, and returning acetic acid to the oxidation step (Hindmarsh et al. and Lee et al. ). To recover acetic acid as a cyclic solvent stream, an acetic acid dehydrating column is necessary. However, a tiny amount of one reactant (PX or MX) may also enter into this acetic acid dehydration column through the feed stream. The... 

Figure 3. Relative quantum yield of trans-cis photoisomerization of polymer containing azo- benzene residues in its chain backbone and of its low molecular weight analog in mixtures of poly (isophorone diamine isophthalamide) and dimethyl-sulfoxide. Polymer (P-IIi) Copolyamide of iso-phthalic acid with isophorone diamine containing 1.5 mole % 4,4 -azodianiline. Analog (A-II) ...

Unsaturated low molecular weight (M between 1000 and 10000), often branched, used as macromonomers for synthesis of thermosets (polyester resins), or thermosetting materials by themselves (alkyd resins). They are prepared from several monomers, namely phthalic and maleic anhydrides, adipic acid, iso-phthalic acid, natural fatty acids or triglycerides, and a great variety of multifunctional alcohols. In a few special cases, they may be saturated and/or linear for use as macromonomers in the production of polyurethanes or other polymers. 

Related to the sulfoacid esters and amides are materials derived from sulfonated polycarboxylic acids. Such polyacids include succinic, itaconic, phthalic, and iso-phthalic acids and the tricarbaUylates. The presence of several carboxylic acid groups in these materials opens the way for the preparation of a variety of multifunctional surfactant molecules. 

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