ISSN:
1572-8935
Keywords:
Bis(p-aminophenoxy)biphenyl
;
Polyimides
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
Abstract Three biphenyl unit-containing diamines,4,4′-bis(p-aminophenoxy)biphenyl (IIIa), 2,2′-bis(p-aminophenoxy)biphenyl (IIIb), and 3,3′,5,5′-tetramethyl-4,4′-bis(p-aminophenoxy)biphenyl (IIIc), were prepared by the chlorodisplacement ofp-chloronitrobenzene with 4,4′-biphenol (Ia), 2,2′-biphenol (Ib), and 3,3′,5,5′-tetramethyl-4,4′-biphenol (Ic), respectively, giving the corresponding bis(nitrophenoxy) compounds IIa-c, followed by catalytic reduction with palladium (Pd) and hydrazine. Three series of polyimidesp-PI,o-PI, and Me-PI were prepared from diamines IIIa-c and aromatic tetracarboxylic dianhydrides via a two-stage procedure that included ring-opening polyaddition to give poly(amic acid)s followed by thermal cyclodehydration to polyimides. The resultant three series of poly(amic acid)s had inherent viscosities of 1.09–2.83, 0.78–1.93, and 1.55–3.09 dL/g, respectively. Almost all the poly(amic acid)s could be solution-cast and thermally converted into transparent, flexible, and tough polyimide films. All the polyimides were characterized by solubility, tensile test, wide-angle X-ray scattering measurements, differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). Effects of the structures of aromatic diamines and dianhydrides on the properties of polyimides were investigated.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01493428
Permalink