Heat‐resistant polymers with thianthrene analog units. II . Aromatic polyamides

Abstract

A series of polyamides which contained thianthrene, phenoxatiin, and dibenzo‐p‐dioxin units was synthesized from tricyclic fused‐ring diamines and aromatic diacid chlorides by solution polycondensations at a low temperature. The amorphous polyisophthalamides were highly soluble in polar organic solvents, whereas some of the polyterephthalamides with a fair degree of crystallinity were insoluble. The solubility of the series of polyamides increased in the order of the dibenzo‐p‐dioxin‐containing polymers < phenoxatiin‐containing polymers < thianthrene‐containing polymers. The thermal stability increased in the reverse order and the dibenzo‐p‐dioxinpolyamides were more thermostable than the corresponding open‐chain polymers with diphenyl ether linkages. The polyamides derived from 2,8‐oriented tricyclic diamines showed somewhat lower glass transition temperatures than those from 2,7‐oriented diamines.

Thianthrene as an activating group for the synthesis of poly(aryl ether thianthrene)s by nucleophilic aromatic substitution

“…Polydithiathianthrenes have been made in which the backbone of the polymer consists completely of thianthrene units 29. Numerous thianthrene and thianthrene tetraoxide containing polyimides30–33 and polyamides34, 35 have also been studied. This article reports the first demonstration of incorporating a thianthrene group into the backbone of poly(aryl ether)s. Furthermore, the thianthrene heterocycle is investigated as the activating group for S N Ar in forming the poly(aryl ether thianthrene)s.…”

Thianthrene-Containing Polymers: Polyimides, Aramids, and Polybenzoxazoles

“…Reacting thianthrene diamines with terephthalic and isophthalic acid chlorides at low-temperature in Nmethylpyrrolidinone (NMP) gave novel aramids. 27,33 X-Ray diffraction indicated that the polyterephthalamides had significant crystallinity, whereas the polyisophthalamides were amorphous. The amide functionality increased solubility compared to polyimides containing thianthrene, benzo-p-dioxin and diphenyl sulfide units.…”

“…27,28 Several examples include reactions of substituted bis(o-iodophenyl) disulfide with copper, 29 thermal cyclization of substituted 2-mercaptophenyl phenyl sulfide, 30 aprotic diazotization of substituted 2-(phenylthio)phenyl-2-aminophenyl sulfide, 31 and thermal elimination of nitrogen from substituted 1,2,3-benzothiadiazole. 32 The advantage of using these reactions is the possibility of controlling the position of substitution.…”

Poly(arylene sulfide)s by nucleophilic aromatic substitution polymerization of 2,7‐difluorothianthrene

“…Polymers containing the thianthrene group have been prepared that exhibit good semiconducting properties for applications in light emitting diodes 16, 17. The nonplanar conformation of the thianthrene heterocycle has been shown to improve solubility and processability of many polyamides18, 19 and polyimides15, 20, 21 by hindering crystallinity in these materials and decreasing polymer chain packing. Numerous other thianthrene containing polybenzoxazoles,22 polyquinolines,23 and poly(aryl ether)s24 have also been prepared.…”