IMIDE COPOLYMER

Poly(phenylquinoxaline—arnide—imides) are thermally stable up to 430°C and are soluble in polar organic solvents (17). Transparent films of these materials exhibit electrical insulating properties. Quinoxaline—imide copolymer films prepared by polycondensation of 6,6 -meth5lene bis(2-methyl-3,l-benzoxazine-4-one) and 3,3, 4,4 -benzophenone tetracarboxyUc dianhydride and 4,4 -oxydianiline exhibit good chemical etching properties (18). The polymers are soluble, but stable only up to 200—300°C. 

Siloxane-Urea, Siloxane-Amide and Siloxane-Imide Copolymers... 

Amine-terminated siloxane oligomers have also been utilized in the synthesis of various siloxane-amide and siloxane-imide copolymers, High molecular weight siloxane-amide copolymers have been synthesized by the solution or interfacial co-polymerization of siloxane oligomers with sebacoyl chloride or terephthaloyl chloride respectively 1S5,165). In some reactions diamine chain extenders have also been utilized. Thermal and dynamic mechanical characterization of these copolymers have shown the formation of multiphase systems160). Compression molded films displayed very good elastomeric properties. 

Recently siloxane-imide copolymers have received specific attention due to various unique properties displayed by these materials which include fracture toughness, enhanced adhesion, improved dielectric properties, increased solubility, and excellent atomic oxygen resistance 1S3). The first report on the synthesis of poly(siloxane-imides) appeared in 1966, where PMDA (pyromellitic dianhydride) was reacted with an amine-terminated siloxane dimer and subsequently imidized 166>. Two years later, Greber 167) reported the synthesis of a series of poly(siloxane-imide) and poly(siloxane-ester-imide) copolymers using different siloxane backbones. However no physical characterization data were reported. 

Development of several new siloxane-imide copolymers for commercial applications have also been reported by Lee 181) and Berger58). Although no information was given in terms of the chemical compositions of these materials, most of these polymers were reported to be processable by solution or melt processing techniques, most probably due to their high siloxane contents. However, due to the presence of low (—20 to —120 °C) and high (>230 °C) temperature Tg s, it was clear that multiphase copolymers have been synthesized. Molecular weights and thermal stabilities, etc, were not reported. 

In most of the studies discussed above, except for the meta-linked diamines, when the aromatic content (dianhydride and diamine chain extender), of the copolymers were increased above a certain level, the materials became insoluble and infusible 153, i79, lsi) solution to this problem with minimum sacrifice in the thermal properties of the products has been the synthesis of siloxane-amide-imides183). In this approach pyromellitic acid chloride has been utilized instead of PMDA or BTDA and the copolymers were synthesized in two steps. The first step, which involved the formation of (siloxane-amide-amic acid) intermediate was conducted at low temperatures (0-25 °C) in THF/DMAC solution. After purification of this intermediate thin films were cast on stainless steel or glass plates and imidization was obtained in high temperature ovens between 100 and 300 °C following a similar procedure that was discussed for siloxane-imide copolymers. Copolymers obtained showed good solubility in various polar solvents. DSC studies indicated the formation of two-phase morphologies. Thermogravimetric analysis showed that the thermal stability of these siloxane-amide-imide systems were comparable to those of siloxane-imide copolymers 183>. 

Siloxane-amide copolymers 30, 33 Siloxane-amide-imide copolymers 30 Siloxane-fary] ether) copolymers 43 - —, properties of 43,44 - —, synthesis of 43, 44 Siloxane-bismaleimides 35 Siloxane bond length of 6... 

Arylene ether/imide copolymers were prepared by the reaction of various amounts 4,4 -carbonylbis[Ar-(4 -hydroxyphenyl)phthalimide] and 4,4 -biphenoi with a stoichiometric portion of 4,4 -dichlorodiphenyl sulfone in the presence of potassium carbonate in NMP/CHP [55]. To obtain high molecular weight polymer, the temperature of the reaction was kept below 155 °C for several hours before heating to >155°C in an attempt to avoid undesirable side reactions such as opening of the imide ring. The imide ring is not stable to conditions of normal aromatic nucleophilic polymerizations unless extreme care is exercised to remove water. Special conditions must be used to avoid hydrolysis of the imide as previously mentioned in the section on Other PAE Containing Heterocyclic Units and as practiced in the synthesis of Ultem mentioned in the Historical Perspective section. 

Poly(metal phthalocyanine)imide copolymers are produced from the reaction of metal (II) 4,4, 4",4" -phthalocyanine tetramine (Cu, Co, Ni), diamines 4-phenyl-ene, 4,4 -bis(4-aminophenyl)methane, 9,9 -bis(4-aminophenylfluorene) and 1,2,4,5-benzene tetracarboxylic dianhydride [69]. 

EP 323142 (European) 1989 Ternary polyether ketone blend wire insulations Pirelli General PLC, UK CK Alesbury, RJ Murphy Formulation shows excellent stress craze resistance, flexibility and flame resistance Blends of polyarylene ether ketones, polyether imides and polyfimide siloxanes) were coated onto wire for solvent resistance, O index and abrasion resistance. Blends without siloxane-imide copolymer did not meet these properties... 

Blend of poly(siloxane imide) copolymer (75%) and PBI (25%) total siloxane content 30% +2.95... 

Kapton Kapton coated with -1500 A poly(siloxane imide) copolymer with 50% siloxane 22.93 5.96... 

There are a few alternative approaches to imide copolymers that allow the resin producer to make imide-modified high heat ABS without incurring the cost of the synthesized imide monomer. One is by reacting styrene-maleic anhydrides with a primary amine, either during the polymerization reaction with styrene or in a separate step. Mitsubishi Monsanto has practiced imidiza-tion on a commercial scale and described a process which follows the formation of S-MA with addition of amine and AN [60]. They described the manufacture of maleimide copolymers by heating the SMA copolymers with aniline in an extruder [61]. The maleimidation of the anhydride function is not complete, as there is unreacted amine or maleic anhydride in the product. The polymer stability and physical properties depend on the mole percent of maleimidation. 

In contrast, the foams derived from the a-methylstyrene and styrene-based copolymers showed pore sizes ranging from 200 to -1800 A, values which are considerably larger than the size of the microdomains of the initial copolymer (Fig. 13). Furthermore, the pores in these samples appear to be more interconnected than those obtained from the fully imidized copolymers. Finally, the... 

With the growing demand for coextruded products, barrier plastics have shown significant growth in the last several years. Historically, the high barrier resins market has been dominated by three leading materials — vinylidene chloride (VDC) copolymers, ethylene vinyl alcohol (EVOH) copolymers, and nitrile resins. Since 1985, however, there has been a lot of interest worldwide in the development of moderate to intermediate barrier resins, as apparent from the introduction of a number of such resins, notably, aromatic nylon MXD-6 from Mitsubishi Gas Chemical Company, amorphous nylons SELAR PA by Du Pont and NovamidX21 by Mitsubishi Chemical Industries, polyacrylic-imide copolymer EXL (introduced earlier as XHTA) by Rohm and Haas and copolyester B010 by Mitsui/Owens-Illinois. 

Kamax. [Rohm Haas] Acrylic-imide copolymer amorphous thermoplastic for inj. molding, outdoor, lighting, optical applies. 

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