Polymethacrylimide Foam Material Performance And Density Relation Research

As a new type of polymer foam materials,polymethacrylimide (PMI) foam with characteristics of light weight, high strength, high heat resistance, high temperature creep resistance and so on, replacing of cellular materials, has always been used as complement of carbon fiber to form skin fiber laminated composite materials. Because of its excellent heat resistance, PMI can implement one-time curing with skin under the harsh condition of 180/0.7MPa, which other commercial foam cannot achieve. At the same time, it can be used as the core composite material integrating structure and function. Comparing with the honeycomb, PMI foam has great advantage of high edgewise compressive strength and low cost. So PMI foam material is increasingly widely used in wind power generation, locomotive, new energy vehicles, and ships, aerospace, medical and sports equipment and other fields.Now the studies of the PMI foam are mainlv focused on the performance and application of ROHACELL (?)MI produced by Rohm &Hass Company. Studies of preparation and application of the PMI in China started relatively late, and the focus is mainly on the chemical structure and produce of the PMI foam. Yet studies on the localization of PMI foam is rare. To solve this problem, this paper studies on KHPMI-RS foam material, which developed and industrialized by the Institute of chemistry of Chinese Academy of Sciences, and discusses the performance and user-concerned use of KHPMI-RS foam Then compare the performance with similar products abroad. The main content of this paper are as follows.By comparing the plastic and rigid foam materials testing standards, we determine the methods in testing mechanical properties, thermal properties and heat deformation temperature and creep resistant properties of the PMI foam products; we also study the connection between process parameters and properties of the products, which provides theoretical basis to improve the comprehensive properties of the product; besides, as to the problems users care about, we study the storage environment effect on the properties of the material and how to reduce this influence.After comparing and analyzing the different positions, same batch and different batch of the 50RS、75RS、110RS dimensional KHPMI foam, we find that, KHPMI-RS’s density meets the requirements of±10; Thermal deformation temperature and density is not closely related, the thermal deformation temperature of different versions of KHPMI foam varies from 210℃ to 230℃; Mechanical properties and creep resistance are closely related with density. With the increase of density, KHPMI RS’s mechanical properties and creep resistance both improve; The compression strength of 50RS、75RS、110RS is respectively 0.8MPa, 1.8MPa,3.7MPa. The creep resistance of different versions of KHPMI foam is Less than 2%, the test temperature of 50RS、75RS、110RS are respectively 130℃.150℃、180℃.In order to guide the users to use KHPMI foam more efficiently,this paper studies KHPMI-RS’s storage stability, and discussed how to eliminate the effect that moisture absorption decrease the material performance by using heat treatment. For example, under the condition of 25℃ and 50% humidity,110RS’s compression strength is 3.1 MPa, and it can last for 180days. After 4 hours of 130℃ drying process, its compression strength is 3.3 MPa.