Method of preparing carbon nanofiber reinforced polymethacrylimide foam through suspension polymerization

Abstract

The invention discloses a method of preparing carbon nanofiber reinforced polymethacrylimide foam through suspension polymerization. The method comprises the steps that firstly, a dispersion medium and a suspension agent are added into a first reactor, and stirring is performed; secondly, monomers are added into a second reactor, the second reactor is heated to a reaction temperature, then an initiator and carbon nanofibers are added, and then the second reactor is placed in an ultrasonic dispersion instrument for ultrasonic dispersion under a constant-temperature condition; thirdly, a mixed liquid obtained after dispersion in the second reactor is poured into the first reactor which is heated to the reaction temperature, stirring is performed for a suspension polymerization reaction, anda prepolymer is obtained; fourthly, a cross-linking agent and a foaming agent are added into the prepolymer, and an extruding machine is adopted to extrude the mixture; and fifthly, the extruded mixture is placed in a mold for foaming heat treatment molding, and the carbon nanofiber reinforced polymethacrylimide foam is obtained. The foam has the advantages that mechanical properties are excellent, reaction time is short, the finished product rate is high, and large-scale production is easy.

Description

technical field [0001] The invention belongs to the field of materials, and relates to a preparation method of polymethacrylimide foam, in particular to a method for preparing nanometer carbon fiber reinforced polymethacrylimide foam by suspension polymerization. Background technique [0002] Polymethacrylimide (PMI) foam is currently under the same density, the strength and stiffness of PMI foam are significantly better than other foam materials, and its density and mechanical properties make it widely used in the aerospace field, mainly as a core material Form a sandwich structure with composite materials. PMI foam was used for the first time on the main load-bearing structure of the A380 aircraft, and it was applied to the rear pressure frame and inner and outer ailerons. In the future, higher requirements will be put forward for the mechanical properties of polymethacrylimide foam. The traditional method of increasing the mechanical properties by increasing the density ...

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Problems solved by technology

The invention patent with the application number 201310502487.9 discloses a preparation method of graphene-enhanced polymethacrylimide foam material, which obtains foam material with better mechanical properties through graphene-enhanced polymethacrylimide foam material. However, when graphene is combined with a polymer, the graphene surface is inert, does not contain any active groups, and has very little interaction with the polymer matrix. Therefore, the most critical step is to uniformly disperse graphene into the polymer matrix. However, ultrasonic dispersion cannot ensure the maximum contact surface between graphene and polymer matrix, which will directly affect the mechanical properties of composite materials.

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