Highly refractive and organo‐soluble poly(amide imide)s based on 5,5′‐thiobis(2‐amino‐4‐methyl‐thiazole): Synthesis and characterization

Abstract

A new thioether-bridged diimide-diacid (DIDA) monomer was synthesized from the condensation of 5,5 0 -thiobis(2-amino-4-methyl-thiazole) (DA) and trimellitic anhydride at 1 : 2 molar ratio. A series of novel organic-soluble poly(amide imide)s (PAIs) bearing flexible thioether linkages and heteroaromatic thiazole groups were synthesized from DIDA with various commercially available aromatic diamines (1-5) via a direct polycondensation method with triphenyl phosphite and pyridine. The resulting polymers were obtained in high yields and possessed inherent viscosities in the range of 0.47-0.91 dL g -1 . All of the polymers were amorphous in nature, showed good solubility and could be easily dissolved in amide-type polar aprotic solvents (e.g., N-methyl-2-pyrrolidone, dimethyl sulfoxide, and N,N-dimethylacetamide), and even dissolved in less polar solvents (e.g., pyridine and tetrahydrofuran). They showed excellent thermal stability with glass transition temperatures between 233-269 C and 10% weight loss temperatures in excess of 480 C in nitrogen and 450 C in air atmosphere. The flexible structure endowed the PAI films with good optical transparency. The optical transmittances of the PAI films at 450 nm were higher than 80% for the thickness of approximately 10 lm. Moreover, the thiazole moieties and flexible thioether linkages in the molecular chains of the PAIs provided them with high refractive indices of 1.7329-1.7509 and low birefringences of 0.0065-0.0098. V C 2012 Wiley Periodicals, Inc. J Appl Polym Sci 125: [1521][1522][1523][1524][1525][1526][1527][1528][1529] 2012

Synthesis and structure–property relationships of novel thiazole‐containing poly(amide imide)s with high refractive indices and low birefringences

“…In our previous works, an increase in solubility of polymers in low‐toxicity solvents was achieved by the introduction of flexible thioether linkages into the polymer backbones. In addition, recent studies demonstrated that bulky groups in the polymer backbone or as pendant groups can enhance the solubility and processability of aromatic PAs and PIs, without any significant reduction in thermal stability .…”

“…In recent years, our research group has been developing structurally modified PAs and PIs with improved solubility and processability through the introduction of sulfur‐containing linkages (—S—, —SO— or —SO 2 —), non‐coplanar structures and bulky pendant groups into the polymer backbones . It was found that the incorporation of both hydrogen‐bonded amide groups and flexible thioether linkages resulted in poly(amide imide)s (PAIs) with enhanced solubility and processability . Aromatic PAIs possess desirable characteristics as they retain good mechanical properties at high temperatures when compared with aromatic PIs.…”

“…A series of solution‐processable PAIs were prepared by polycondensation of DIDA with various aromatic diamines. The structure–property relationships of these PAIs due to the presence of phenyl substituents were studied by comparison with the reported analogous polymers containing methyl groups …”

Synthesis and properties of polyamides derived from 4,6-bis(4-chloroformylphenylthio)pyrimidine and 3,6-bis(4-chloroformylphenylthio)pyridazine

“…In particular, the introduction of the sulfur atom is an effective way to prepare high refractive index polymers for its high molar refraction and low optical dispersity of refractive index. There have been many reports on sulfur‐containing optical polymers including epoxies, polyurethanes, polymethacrylates, polyarylenethioethers and polyimides . Among them, polyimides (PIs) are promising candidates for advanced optical applications.…”

Synthesis of aminothiazoles: polymer-supported approaches

“…25 This class of compounds is well known as a prodrug for the treatment of type-2 diabetes, 26 and aminothiazole-4-carboxylate derivatives are known as active compounds against Mycobacterium tuberculosis H37Rv and aketoacyl-ACP synthase mtFabH. 27 Aminothiazoles are also useful in the synthesis of polymers 28,29 and dyes. 30,31 Due to the multi-dimensional importance of aminothiazoles and their derivatives, several methods have been reported in the literature for their synthesis.…”