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Synthesis and comparative study on polyetherimides from isomeric 4,4′‐isopropylidenediphenoxy bis(phthalic anhydride)s
Author(s) -
Jiang Hongyu,
Jiang Hanzhou,
Chen Guofei,
Fang Xingzhong
Publication year - 2021
Publication title -
journal of polymer science
Language(s) - English
Resource type - Journals
eISSN - 2642-4169
pISSN - 2642-4150
DOI - 10.1002/pol.20210111
Subject(s) - phthalic anhydride , phthalimide , solubility , phthalonitrile , polymer chemistry , ultimate tensile strength , materials science , polyetherimide , chemistry , organic chemistry , polymer , composite material , catalysis , phthalocyanine
Two isomers of commercial 4,4′‐(4,4′‐isopropylidenediphenoxy) bis(phthalic anhydride) (4,4′‐BPADA), that is, 3,4′‐(4,4′‐isopropylidenediphenoxy) bis(phthalic anhydride) (3,4′‐BPADA) and 3,3′‐(4,4′‐isopropylidenediphenoxy) bis(phthalic anhydride) (3,3′‐BPADA), were synthesized through aromatic nucleophilic substitution from nitrophthalonitrile and bisphenol A. 3,4′‐BPADA was first synthesized from two intermediates, that is, 3‐(4‐[4‐hydroxyphenylisopropylidene] phenoxy) phthalonitrile (3‐BPADN) and 3,4′‐(4,4′‐isopropylidenediphenoxy) bis(phthalonitrile) (3,4′‐BPATN). The corresponding three series of polyetherimides (PEIs) were prepared with two representative aromatic diamines (4,4′‐oxydianiline and m ‐phenylenediamine ( m ‐PDA)) via two‐step procedure and chemical imidization. Isomeric polyimides showed T g s from 206 to 256°C in nitrogen and T d5% s from 488 to 511°C in argon, good mechanical properties (tensile moduli of 2.3–3.3 GPa, tensile strengths of 70–96 MPa, and elongations at break of 3.2%–5.1%), and good solubility. With the introduction of 3‐substituted phthalimide unit, PEIs displayed higher T g values, lower strengths and elongations, better solubility and larger d ‐spacings. The rheological properties of thermoplastic polyimide resins based on the BPADA isomers were investigated, which showed that polyetherimide PEI‐3b derived from 3,3′‐BPADA and m ‐PDA had the lowest melt viscosity among the isomers, indicating that the melt processibility had been greatly improved.