The manufacturing of auxetic and conductive foam composites utilizing a novel kinetic model
Topic(s) : Material science
Co-authors :
Yoon Min OH (KOREA, REPUBLIC OF), Kyeong Mo KANG (KOREA, REPUBLIC OF), Jin Soo CHOI (KOREA, REPUBLIC OF), Ineui JEE (KOREA, REPUBLIC OF), Woong-Ryeol* YUAbstract :
Polymer foam, with its exceptional properties like light weight, compressibility, shock absorption, chemical stability, and thermal insulation, is gaining much attention across diverse industries like automotive, aerospace, construction, and healthcare. Polyurethane, PVC, and epoxy commonly serve as the matrix material, while recent research strives to enhance foam properties by incorporating nano-fillers like carbon black or graphene into composite materials. The blowing agents used in manufacturing polymer foam can be broadly categorized into two types: physical blowing agents injecting strong gases and chemical blowing agents generating foaming gas through reaction Chemical blowing agents generating foaming gas through heat- or light-triggered reactions are particularly popular in research due to their simple processes, uniform foam production, and quantifiable reaction analysis. On the other hand, recent research emphasizes the use of thermally and chemically stable thermosetting polymers in foam production. Here, synchronizing the timing of polymer curing and foaming agent expansion is crucial. If the foaming reaction is too rapid, the foam might lose its shape before curing, while excessively fast curing could hinder expansion by solidifying the polymer skeleton. Establishing kinetic models for curing and foaming reactions forms the foundation for designing foam materials based on these reactions.
However, using conventional kinetic modeling approaches, distinguishing between curing and foaming reactions becomes challenging when they occur simultaneously in a similar temperature range, as observed in the foam production process. To address this, firstly this study defines the degree of curing using base materials without blowing agents. Second, the extent of expansion of the material is characterized by observes real-time pressure changes within a sealed pressure cylinder during the reaction. Using these two data, kinematic modelling combining curing and expansion as functions of time and temperature was performed, enabling to predict the foaming behaviour of material precisely. Recent attention has been directed towards developing composite structures of auxetic foam, known for their negative Poisson's ratio, but there has been scarce research dedicated to kinetic modeling in this context. Therefore, a new molding process has been explored to manufacture auxetic and conductive foams in a mold at a once using graphene and developed kinematic modelling.
However, using conventional kinetic modeling approaches, distinguishing between curing and foaming reactions becomes challenging when they occur simultaneously in a similar temperature range, as observed in the foam production process. To address this, firstly this study defines the degree of curing using base materials without blowing agents. Second, the extent of expansion of the material is characterized by observes real-time pressure changes within a sealed pressure cylinder during the reaction. Using these two data, kinematic modelling combining curing and expansion as functions of time and temperature was performed, enabling to predict the foaming behaviour of material precisely. Recent attention has been directed towards developing composite structures of auxetic foam, known for their negative Poisson's ratio, but there has been scarce research dedicated to kinetic modeling in this context. Therefore, a new molding process has been explored to manufacture auxetic and conductive foams in a mold at a once using graphene and developed kinematic modelling.