ISOPHTHALIC ANHYDRIDE

Aromatic polyanhydrides meta isophthalic anhydride (IPA) para terephthalic anhydride (TA)... 

In the coating industry, polyesters are characterized by resins based on components that introduce unsaturation (—C=C—) directly into the polymer backbone. The most common polyester resins are polymerization products of maleic or isophthalic anhydride or their acids. In producing paint the polyester resin is dissolved in styrene monomer, together with pigment and small amounts of inhibitor. A free radical initiator, commonly a peroxide, and additional styrene are packaged in another container. When applied, the containers are mixed. Sometimes, because of the fast initiating reaction (short pot life) they are mixed in an... 

Biodegradable copolymers of fumaric anhydride and isophthalic anhydride were synthesised by the melt condensation polymerisation of purified prepolymer mixtures and formulated into microspheres loaded with theophylline and diltiazem hydrochloride using a solvent extraction procedure. The important parameters of the microencapsulation process were identified and in vitro... 

Figure 14.4 gives plots of viscosity (log ri) versus cure time for different shear rates (y) when a general-purpose unsaturated polyester (Aropol 7030, Ashland Chemical Company) was subjected to steady-state shear flow in a cone-and-plate rheometer under an isothermal condition at 60 C. The resin had been prepared by the reaction of propylene glycol with a mixture of maleic anhydride and isophthalic anhydride. The resin system used in Figure 14.4 was cured with BPO as initiator and a solution of 5 wt % A,A-dimethylaniline, diluted in styrene, as accelerator. The following observations are worth noting in Figure 14.4. At an early stage of curing, the rj increased slowly, but then...

Poly(2,2 -adipainidodibenzoic isophtbalic anhydride) Poly(4,4 -adipamidodibenzoic isophthalic anhydride) Poly(2.2 -adipainidodibenzoic terephIhaUc anhydride) Poly(4,4 -adipainidodibenzoic terephlhaUc anhydride) Poly(acUpic anhydride)... 

Isopropylidenediphenylene)dioxydiacetic pyridinedicarboxylic anhydride 3,4 -(Ethylenedioxy)diphenylene 3,3, 4,4 -Oxydiphenylenetetracarboximide 4,4 -(Etbylenedioxy)dibenzoic isophthalic anhydride 4,4 -(Ethylenedioxy)dibenzoic phthalic anhydride 4,4 -(Ethylenedioxy)dibenzoic terephthalic anhydride Isophthalic (isopropylidenediphenylene)diacetic anhydride 4,4 -(Isopropylidenediphenylene(dioxydiacetic terephthalic anhydride 4,4 -(Ethylenedioxy)diphenylene carbonyldiphenylenetetracarboximide Neopentylene-4,4 -diphenylene 3,3, 4,4 -carbonyldiphenylenetetracarbox... 

Diallyl Isophthalate. DAIP polymerizes faster than DAP, undergoes less cyclization, and yields cured polymers of better heat resistance, eg, up to ca 200°C. Prepolymer molding materials such as Dapon M of EMC, are not sticky. Maleic anhydride accelerates polymerization, whereas vinyl isobutyl ether retards it and delays gelation in castings. Copolymers with maleic anhydride are exceptionally hard and tough and may scratch homopolymer surfaces. 

Systems based on isophthalic acid often show better water and alkali resistance than those based on phthalic anhydride. This is not thought to be due to inherent differences between the phthalic and isophthalic structures but is ascribed to the fact that isophthalate resins have generally considerably higher viscosities which enable them to be diluted with greater amounts of styrene. It is the additional proportion of styrene which gives the improved water and alkali resistance. 

Ammoxidation of isophthalic acid produces isophthalonitrile. The reaction resemhles the one used for ammoxidation of phthalic anhydride ... 

On heating the silylated bisamine 2185 with diphenyl isophthalate 2186 the polyamide 2187 and phenoxytrimethylsilane 13d are formed [2, 8]. On reacting 2185 with 4-chloroformylphthalic anhydride 2188 at 50 °C MesSiCl 14 is ehminated to give 2189, which cyclizes with ehmination of trimethylsilanol 4 or hexamethyldi-siloxane (HMDSO) 7 at 200°C to give the polyamide 2190 [1, 2, 9] (Scheme 14.1). 

Isophthalic/Terephthalic Acid Polyester Typically, isophthalic acid is reacted in a two-stage process with glycols such as propylene or neopentyl glycol and then with maleic anhydride. The crosslinked, fully cured isophthalic-based composites exhibit good weathering resistance and good corrosion resistance to acid media. 

In the characterization of alkyd resin formulations the palmitic acid to stearic acid (P/S) ratio, often used to identify the type of oil in a binder, cannot be applied as many different oils other than the traditional ones are commonly employed in industrial formulations. Moreover, they are often in mixtures, with the additional complication that fatty acids are also sometime added to the vegetable oils, thus making it impossible to rely on measured P/S values. In any case it is important to always derivatize the samples if Py-GC/MS is used and an alkyd is suspected. Phthalic anhydride will be detected also in an underivatized alkyd pyrogram however, isophthalic acid will not, leading to confusion and the possibility of uncorrected identification [92]. 

All maleimides were synthesized according to standard procedures.16 Maleic anhydride, dimethyl maleate, and diethyl fiimarate were purchased from Aldrich Chemical Co. and used as received. 1,4-Cyclohexanedimethanol divinyl ether (CHVE) and tetraethylene glycol divinyl ether (CHVE) were used as received from International Speciality Products. Bis(4-vinyloxybutyl) isophthalate (IPDBVE) and bis(vinyloxybutyl)succinate (SEGDVE) were obtained from Allied-Signal and used without further purification. All acrylates were used as received from either Aldrich Chemical Co. or Scientific Polymer Products. 2,2-Dimethoxy-2-phenylacetophenone (DMAP) was used as received from Ciba Specialty Chemicals. 

Instead of phthalic anhydride, isophthalic acid can be used as is done in USA. Its use is in increasing. Polyhydric alcohols like pentaerythritol, trimethylolpropane and sorbitol are also used. Some-times small quantities of diols like ethylene glycol and propylene glycol are used to reduce cross-linking. 

The isophthalic acid, maleic anhydride and glycol resins. These are generally referred to as isophthalic resins , or simply iso resins . 

The blending of DCPD resins has become an important practice. Typical blended resins include combinations of DCPD resins with isophthalic, orthoph-thalic or vinyl ester resins. Creating blends with higher-molecular-weight phthalic anhydride, isophthalic or vinyl ester resins can toughen neat DCPD resins, which are inherently brittle. In the case of vinyl ester and isophthalic and DCPD blends, a degree of improved chemical resistance and hydrolytic stability can be gained. 

Anhydride s/Acids Phthalic anhydride Malice anhydride Adipic acid Isophthalic acid Terephthalic acid Glycols... 

Tooling/molds anhydride resin blends Isophthalic... 

Body panels glycol/isophthalic Propylene glycol/phthalic anhydride... 

AMINOHEPTANE ISOPHTHALOYL CHLORIDE PHTHALIC ANHYDRIDE ETHYNYLBENZENE ISOPHTHALIC ACID PHTHALIC ACID TEREPHTHALIC ACID BENZOTHIOPHENE INDOLE... 

Smdies of the thermal degradation of several aromatic acids have been reported. Phthalic acid (80), but not isophthalic acid (81) or terephthalic acid (82), decomposes via dehydration to its anhydride at 140-160 °C. However, (81) and (82) and benzoic acid are thermally stable below 200 °C. Dissociation constants of all 19 isomers of methyl-substimted benzoic acids (83) have been measured in methanol and DMSO. From the pA a values, the substiment effects of the methyl groups were calculated and tentatively divided into polar and steric effects. Also, in the case... 

Uses Preparation of phthalic acid, phthalic anhydride, terephthalic acid, isophthalic acid solvent for alkyd resins, lacquers, enamels, rubber cements manufacture of dyes, pharmaceuticals, and insecticides motor fuels. 

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