Novel hydroxyl‐containing and thermo‐dehydrocyclizable polycondensation polymers for multifunctional materials: Synthesis, properties, application

Abstract

Novel poly(amide‐imide)s and poly(amide‐o‐hydroxy‐imide)s were synthesized in the process of low‐temperature polycondensation of diacid chloride of 2‐(4‐carboxyphenyl)‐1,3‐dioxoisoindoline‐5‐carboxylic acid with a single diamine of 5,5′‐methylenebis(2‐aminophenol (DADHyDPhM) or of 4,4′‐methylenebis(benzeneamine) (DADPhМ), and also with a mixture of named diamines (molar ratios of DADHyDPhM to DADPhМ being equal to 7:3, 1:1, and 3:7). The influence of hydroxy‐imide modifying units (fragments) introduced into the basic poly(amide‐imide) on its thermal stability (the processes of polymers destruction proceed intensively in the temperature range from 400 to 600°C and has a complex character); parameters of pervaporation through heat‐resistant films prepared from polymer solutions were analyzed. Polymer films are rigid materials (modulus of elasticity–3 to 4 GPa) with a strength above 100 MPa. Heating up to 300°C leads for all three compositions to a noticeable increase in the elastic modulus and to a pronounced tendency to increase the strength characteristics.

Effect of Hydroxyl-Containing Fragments on the Structure and Properties of Membrane-Forming Polyamide-Imides

“…In each of these cases, 40 mol% more than one of the monomers (diamines) is introduced into the reaction zone. Such features of the reaction should, in any case, lead to the production of copolymers enriched in one of the components since, as shown in our previous article [ 13 ], in all cases, the composition of the copolymers corresponds to the amount of components introduced into the reaction. We observed a similar effect in the synthesis of polyamide-imides containing carboxyl groups in the diamine component [ 11 ].…”

“…In this work, we studied the structure and properties of (co)polymers synthesized according to a procedure previously developed by us in a prior work [ 13 ]; we also studied the products of their modification via thermal dehydrocyclization. A specific feature of this series of (co)polymers is the decrease in the number of hydroxyl groups in macromolecules upon passing from Hy-coPAI I (m = 1) to Hy-coPAI II–IV (m = 0.7, 0.5, 0.3) and PAI V (m = 0).…”

“…Poly(o-hydroxyamide-imides) (Hy-PAI I and Hy-coPAI’s II–IV) and Poly(amide-imide) (PAI V) with the chemical structures shown in Figure 1 were synthesized according to a previously described procedure [ 13 , 38 ].…”

“…This approach to polymer design can yield non-porous polymeric membranes of complex morphology, which can be characterized by both micro- and macro-heterogeneous supramolecular structures. This gave significant positive results in the development of proton-conducting, pervaporation, and gas separation membranes [ 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 ].…”

“…Another attempt to control the hydrophilic–lipophilic balance of a polymer membrane was made in one of our more recent works [ 13 ] by introducing hydroxyl-containing fragments into the polyamide-imide macrochain. In this work, the novel modification of polyamide-imides was carried out; the fragments (units) containing hydroxyl (hydrophilic) groups in the ortho-position to the amide bond were introduced into the macromolecule.…”