Preparation, characterization, and properties of poly(thioether imide)s from isomeric bis(chlorophthalimide)s and bisthiophenols

Abstract

A series of isomeric poly(thioether imide)s (PTIs) containing thioether linkages were prepared by aromatic nucleophilic substitution reaction of isomeric bis(chlorophthalimide)s (BCPIs) and bisthiophenols. The glass transition temperatures ( Tgs) of the isomeric PTIs were 190–264°C, the 5% weight loss temperature ( T5%) reached up to 441–508°C under nitrogen and 472–520°C in air atmospheres, respectively. It was found that the Tg values of the PTIs from three isomeric BCPIs with the same bisthiophenol increased in the order of 4,4′-BCPI < 3,4′-BCPI < 3,3′-BCPI, while the T5% values gradually decreased in the order of 4,4′-BCPI > 3,4′-BCPI > 3,3′-BCPI. Flexible films that could be cast from the polymer solutions exhibited good mechanical properties with tensile strengths of 91–121 MPa, elongations at break of 8–12%, and tensile moduli of 2.2–2.6 GPa. The minimum melt viscosity of isomeric PTIs decreased with increasing the content of asymmetric 3,4′-substituted phthalimide unit, and the PTI (2c) showed the lowest melt viscosity about 760 Pa·s at 264°C among these isomeric polymers.

Synthesis and characterization of new poly(diketone imide)s derived from 1,4-bis(3,4-dicarboxybenzoyl)benzene dianhydride and various diamines

“…One of the successful approaches to improve their solubility and processability is the introduction of flexible groups, such as O, S, SO 2 , CH 2 , (CH 3 ) 2 C, and (CF 3 ) 2 C moieties into the polymer backbone. [5][6][7][8][9][10][11][12][13][14][15][16][17][18] It is also recognized that ketone links inserted in the polyimide backbone could improve their solubility and mold ability, and various poly(ketone imide)s have been developed from the dianhydride or the diamine component containing ketone moieties. [19][20][21][22][23][24][25][26][27] In addition, several poly(diketone imide)s (PDKIs) using the dianhydride [28][29][30][31][32] or diamine [33][34][35][36][37][38] monomers containing diketone groups were also investigated.…”

New transparent and thermally stable cardo poly(ether imide)s derived from 10,10-bis[4-(4-amino-2-pyridinoxy)phenyl]-9(10H)-anthrone

“…20 –28 To our knowledge, although various colorless PIs have been reported in the last decade, it is still a challenge to develop new PIs with a combination of high T g , excellent optical transparency, good solubility, and high mechanical properties. It is well-known that the presence of flexible ether linkages into the molecular backbone presents the corresponding poly(ether imide)s (PEIs) 29,30 good solubility and processability, but some of their advantageous properties such as thermal stability and mechanical property were somewhat sacrificed. It has been demonstrated that the introduction of rigid heteroaromatic pyridine ring into the polymer main chains could endow it excellent thermal and thermooxidative stability, which is useful in decreasing the negative effects resulting from the incorporation of flexible linkages in the PI backbones.…”

Organosoluble and transparent cardo polyimides with high Tg derived from 9,9-bis(4-aminophenyl)xanthene

“…Therefore, many efforts have been made to overcome the above problems through the chemical structure modification of PIs. Some approaches such as the introduction of flexible linkages [7][8][9] into the polymer backbone and the incorporation of pendent substituents [10][11][12] along the polymer backbone for increasing their solubility and processability have led to considerable success. However, comparison of these approaches for increasing heat resistance and solubility showed that some of them impaired the others.…”