Preparation And Study On The Electrical Conductive Polyurethane Foam

With polyether polyol as matrix, high structure nano-carbon black as electrical conductive filler, triethylenediamine and dibutyltin dilaurate as compound catalyst, chelating coupling agent of organic titanate as interface modifier, a new kind of water blown free rise electrical conductive foam, the volume resistivity of which is 108-109Q .cm is obtained. Characterized by electrical conductivity and excellent polyurethane foam quality , the new functional material is worth studying and enjoys a promising application future.Serving as the electrical conductive filler , CB, for its special surface quality, seriously affects the reaction process, and mechanical or electrical properties . And CB also functions as solid powder emulsifer , nucleating agent (bubble nucleating agent crystal nucleating agent) , solid powder stabilizer agent and so on through the whole reaction process .Considering disadvantageous effects of CB , we focus our study on the formula ,the interface intermiscibility of CB / polyether polyol , the dispersion and the influence of CB to the properties of the foam, and the influence on foaming behavior and microphase separation .We also build a model of emulsion and stabilization .Our experiment is subdivided into study on modifying function of coupling agent through surface(interface) chemical principal, the degree of microphase separation through IR and DMA,the mechanical properties through tensile test and the electrical property through measuring the volume resistivity, respectively.The results indicate that CB greatly enhances the viscosity of the disperse system, and also seriously affects the foaming behavior and workability. And the affection will be greater with smaller size and higher structure endowing foam with good electrical conductivity .As bubble nucleating agent, CB causes the number of the bubbles in foam to increase, breaks the equilibrium between foaming reaction and gelatination , and decreases the mechanical properties of the foam; As crystal nucleating agent ,CB brings about the early arrival of microphase separation, increases the separation level, and finally leads to a low opening rate.The uneven dispersion of CB in foam results in higher volume resistivity. The studies show: we can endow the electrical conductive foams with good physical and electrical properties by filling 2%super electrical conductive carbon black into the matrix , using chelating coupling agent of organic titanate with content of 2%-3% to promote the interface intermiscibility, suitably increased the amount of dibutyltin dilaurate and choosing higher activate stabilizer to lessen negative affections to foaming process.