Microcellular polyetherimide/graphene‐polysiloxane composite foam: intercalation structure, mechanical and thermal properties

• Published in: Polymer international 2018-12, Vol.67 (12), p.1655-1663
• Main Authors: Sun, Xuejie, Ye, Lin
• Format: Article
• Language: English
• Subjects: Bulk density; Cell size; Cytology; Graphene; High temperature; intercalation structure; mechanical property; microcellular foam; Organic chemistry; PEI/RGO composites; Phase separation; Polyetherimides; Size distribution; Storage modulus; Thermal degradation; thermal stability; Thermodynamic properties; Thickness; Water vapor
• ISSN: 0959-8103; 1097-0126
• DOI: 10.1002/pi.5690

Based on the industrialized reduced graphene oxide (RGO) product, polyetherimide (PEI)/RGO composite foam was prepared by a water‐vapor‐induced phase separation process by incorporation of polysiloxane (SI) as a compatibilizer. It was found that PEI/SI molecules were intercalated into the RGO layers through strong interfacial interaction and RGO with increased layer thickness was uniformly distributed in the PEI matrix. The composite foam possessed a homogeneous spherical‐like cell structure with narrow cell size distribution and low apparent density. In the range of 0–1 wt% RGO‐SI content, the area under the stress–strain curves increased dramatically, indicating the significantly increased toughness of the composite foam, while the tensile strength reached a maximum of 14.5 MPa at 1 wt% RGO‐SI as a result of the reinforcing effect of RGO‐SI on the foam. The addition of RGO‐SI led to a remarkable increase in Tg. Compared with neat PEI foam, the thermal degradation temperature and char yield of the composite foam clearly increased, while in the range of 0.5–3 wt% RGO‐SI a high storage modulus was maintained at high temperature, reaching about 300 MPa at 200 °C, indicating a remarkable improvement of the thermal mechanical stability of the foam. © 2018 Society of Chemical Industry Polyetherimide (PEI)/reduced graphene oxide (RGO) polysiloxane (SI) composite foam was fabricated via a water‐vapor‐induced phase separation process. RGO‐SI with a uniform dispersion in the matrix presented a thermal stabilizing and reinforcing effect on PEI.