Phenylethynyl-terminated polyimide, exfoliated graphite nanoplatelets, and the composites: an overview

Abstract

In efforts to characterize and understand the properties and processing of phenylethynylterminated imide (LaRC PETI-5, simply referred to as PETI-5) oligomers and polymers as a high-temperature sizing material for carbon fiber-reinforced polymer matrix composites, PETI-5 imidization and thermal curing behaviors have been extensively investigated based on the phenylethynyl end-group reaction. These studies are reviewed here. In addition, the use of PETI-5 to enhance interfacial adhesion between carbon fibers and a bismaleimide (BMI) matrix, as well as the dynamic mechanical properties of carbon/BMI composites, are discussed. Reports on the thermal expansion behavior of intercalated graphite flake, and the effects of exfoliated graphite nanoplatelets (xGnP) on the properties of PETI-5 matrix composites are also reviewed. The dynamic mechanical and thermal properties and the electrical resistivity of xGnP/PETI-5 composites are characterized. The effect of liquid rubber amine-terminated poly(butadiene-co-acrylonitrile) (ATBN)-coated xGnP particles incorporated into epoxy resin on the toughness of xGnP/epoxy composites is examined in terms of its impact on Izod strength. This paper provides an extensive overview from fundamental studies on PETI-5 and xGnP, as well as applied studies on relevant composite materials.Key words: polyimide, exfoliated graphite nanoplatelets, carbon fiber, composite, properties Phenylethynyl-Terminated Imide PolymerPolyimides have been extensively used in the electronics industry [1] as coatings, films, or adhesives and also in composite applications [2] as a primary or secondary structural material. When incorporated with organic or inorganic fibers, including carbon fibers and glass fibers, they can potentially be applied as a sizing material for high-temperature uses. In advanced applications, one of the most desirable advantages of polyimides, especially the aromatic polyimides, is their excellent high-temperature performance. Their thermal characteristics, including high temperature stability and cure behavior, are critical to successful processing and to the final properties of the resulting polyimide. For aerospace and aircraft applications, advanced polymer materials must successfully maintain their properties at high service temperatures over a long exposure time [3][4][5].The important parameters influencing the heat resistance of a polymeric material are its glass transition temperature (T g ), melting point (T m ), thermal stability, and etc., which may depend on its thermal history. Accordingly, polymers that are used to fulfill such high temperature performance should exhibit a high T g or T m and have excellent thermal stability. Even though some polyimides meet the high temperature requirement, their uses have been limited due to processing difficulties, such as poor solubility in common solvents, the release of volatiles, brittleness, and high processing temperature [6,7].Aromatic polyimides, especially acetylene or ethynyl-terminated polyimides, have been extensiv...

A special filler for epoxy resin to enhance the T peel strength of adhesive

“…[ 39,40 ] Meanwhile, it could also provide physical adsorption of polar groups, resulting in higher strength and bending strength than pure EP. [ 41–43 ] Similar to T peel strength, the impact strength and bending strength of TDI 17 ‐GO 0.5 /EP composite material were higher those that of ATBN 25 /EP composite, which resulted from changing interface structure between GO and EP and the force of chemical bond produced by surplus ‐NCO groups. [ 44,45 ] As for ATBN 25 ‐TDI 17 ‐GO 0.5 /EP composite, surplus ‐NCO groups reacted with EP to form a chemical bond and physical adsorption from ATBN, which provide higher bond energy.…”

Developing Highly Tough, Heat-Resistant Blend Thermosets Based on Silicon-Containing Arylacetylene: A Material Genome Approach

“…For example, the PSA resins were modified by dipropargyl ether from melt blending or blended with benzoxazines to improve the toughness. , Despite a series of attempts, there is still a gap from the expected performanceeither the thermal stability is significantly decreased or the toughness is not sufficiently improved. Polyimide, especially thermosetting polyimide capped by reactive end groups, shows excellent comprehensive properties such as pretty good thermal stability, high toughness, and strong adhesion with reinforced fibers. − Compared to the PSA resins, the polyimides exhibit lower thermal stability but better mechanical properties. Because the PSA resins contain alkynyl groups, − the acetylene-terminated polyimide can be selected as a blend to toughen PSA resins via the reaction of the terminal alkynyl groups of two resins during the curing process.…”