S. Andre et al., Novel synthesis of polyimide-polyhybridsiloxane block copolymers via polyhydrosilylation: Characterization and physical properties, J POL SC PC, 39(14), 2001, pp. 2414-2425
Citations number
37
Categorie Soggetti
Organic Chemistry/Polymer Science
Journal title
JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
The insertion of soft polysiloxane segments into a polyimide backbone intro
duces changes in its properties (processability, low surface tension, gas p
ermeability, and lower dielectric constant). Generally, these polyimide-pol
ysiloxane copolymers are synthesized by the condensation of a dianhydride w
ith an aromatic diamine and an amine telechelic polysiloxane, or by transim
idization between an aminopyridine-terminated oligoimide and an amine end-c
apped oligosiloxane. This study investigated another route to obtain perfec
tly alternating polyimide-polyhybridsiloxane (PI-PHSX) block copolymers. Th
e hydrosilylation, widely studied previously, was performed to elaborate co
polymers from an allyl telechelic polyimide and a hydrosilane telechelic po
lyhybridsiloxane. The use of a telechelic polyhybridsiloxane as a soft segm
ent brought better thermostability and better chemical resistance in compar
ison with an oligosiloxane based on Si(CH3)(2)-O- units. Using the same all
yl telechelic polyimide moiety but varying the size of the hybrid siloxane
part, we obtained different PI-PHSX block copolymers, leading to thermoplas
tic elastomers (TPE). We investigated the effect of the soft-segment length
on the thermal resistance, activation energy of thermal degradation, mecha
nical behavior, and surface properties of a series three PI-PHSX block copo
lymers containing 36, 54, and 75 wt % polyimide. (C) 2001 John Wiley & Sons
, Inc.