Study On The Preparation And Performance Of Carbon-silicon Polypropylene Foam Stabilizer

PP foams have been attracting more and more attention as lightweight and recyclable materials suitable for a variety of applications ranging from protective equipment,auto parts,cushions,construction components and electromagnetic wave insulators.However,during the foaming process of polymer,the surface tension will increase,which is a process of increasing Gibbs free energy.This phenomenon is not conducive to the generation of bubbles,leading to the problem of fewer cells and insufficient cell size.The foam stabilizer is a kind of surfactant,which plays an important role in the foaming process.First,the foam stabilizer has an emulsifying effect.Compatibility of the raw materials in the foam formula is poor.The foam stabilizer possesses a lipophilic and hydrophilic molecular structure,which can emulsify foaming raw materials and improve compatibility which allows the foaming and solidifying reaction to proceed smoothly.Second,the foam stabilizer reduces the surface tension of the material,which makes the formation of air bubble nuclei easier.During foaming,the foam stabilizer stabilizes the cell wall by reducing the stress in the cell wall to prevent the foam from collapsing.As a result,the stable foam body can be obtained.This topic is to develop a carbon-silicon type foam stabilizer for PP.This type of foam stabilizer can make the foam evenly mixed during the PP foaming process,reduce the surface tension of the system to promote nucleation and play a role in supporting the foam.The main research contents are as follows:(1)The foam stabilizer is prepared by a simple one-step strategy using fatty acid and amino silicone oil as reactants(FA-SI).The foam stabilizer is characterized by infrared spectroscopy and elemental analysis.In the foaming process of PP,the synthetic foam stabilizer is used to obtain foamed PP foam,and its mechanical properties,apparent density,and cell morphology are studied.The foam stabilizer significantly reduces density and cell diameter of the foam.When the amount of foam stabilizer is 1.0wt%,the density drops to 0.958g/cm3,about 2.8%lower vs.foam generated without stabilizer.The tensile strength increases to 18.4MPa from 16.1 MPa,and the elongation at break increases to 495%from 328%.(2)The foam stabilizer is prepared by a simple one-step strategy using maleic anhydride grafted polyethylene and amino silicone oil as reactants(PE-SI).In the foaming process of PP,the synthetic foam stabilizer is used to obtain foamed PP foam,and its mechanical properties,apparent density,and cell morphology are studied.The foam stabilizer significantly reduces density and cell diameter of the foam.When the amount of foam stabilizer is 1.0wt%,the density drops to 0.948g/cm3,about 5.0%lower vs.foam generated without stabilizer.The tensile strength increases to 18.9MPa from 16.1 MPa,and the elongation at break increases to 523%from 328%.