Thermal and mechanical properties of blended polyimide and amine‐functionalized poly(orthosiloxane) composites

Abstract

Nanocomposite films were prepared through the blending of polyimide (PI) with octaphenyl silsesquioxane (OPS) and an amino-functionalized analogue, octaaminophenyl silsesquioxane (OAPS), with a solution-casting method. Although the PI-OPS composites showed visible phase separation at 5 wt %, the PI-OAPS composites were transparent with visible phase separation occurring only at 50 wt % OAPS. The interfacial interactions and homogeneity of the composites were characterized with scanning electron microscopy (SEM) and dynamic mechanical analysis. SEM analysis showed a uniform fracture surface for OAPS composites at concentrations up to 20 wt %. Interestingly, OAPS-rich particles with sizes of less than 1 lm were formed within the PI matrix for the 50 wt % composite. The PI-OAPS composites showed higher glass-transition temperatures (T g 's) than the pure PI. The PI-OPS composites showed a T g lower than that of the pure PI, and this suggested poor interfacial interactions. The slightly enhanced thermal stability of PI-OAPS composites (up to 20 wt %) was attributed to the inherent thermal stability of OAPS at higher temperatures. There were small increases in the modulus and strength for the composites with respect to the base polymer.

Segmental dynamics in hybrid polymer/POSS nanomaterials

“…The effect of POSS is non-uniform ranging from strong deceleration to moderate acceleration of dynamics ( Figure 21). (MDA) polyimide [150]. A slight plasticization occurred due to increase of free volume, later confirmed by gas permeation experiments in [151].…”

Synthesis Improvement and Characterization of Polyhedral Oligomeric Octa(aminophenyl)silsesquioxane

“…由于惰性取代基 POSS 与聚合物的 相容性较差, 分子之间并未形成共价键, 而反应性基团 可使其通过接枝或聚合反应与聚合物之间以化学键结 合在一起, 实现分子层次上的均匀分散. 近年来, 越来 越多的研究者倾向于合成和研究带有活性基团的 POSS 纳米分子 [4,5] . 2 结果讨论 …”

The effect of amine substituent chain length on POSS/Polysulfone mixed matrix membrane

“…With the research available, it was shown that the addition of octaphenyl POSS (molecular silica) and octaaminophenyl POSS (multi-functional POSS) into polyimide matrix have led to the formation of phase separation with the former while exhibiting a homogenous morphology with the latter [27]. Another research showed that the addition of poly(ethylene glycol) (PEG) functionalized POSS (multi-functional POSS) in polymer intrinsic microporosity (PIMs) membrane had also led to the formation of phase separation [28].…”