膨胀单体（Expansion monomer）.docVIP

膨胀单体（Expansion monomer） Study on epoxy resin with new expansion monomer Abstract: When a relatively strong and compact body is transformed into relatively fixed and compact form, volume contraction usually occurs. In practical applications, the polymerization shrinkage and shrinkage caused by shrinkage stress brought a series of problems, such as precision casting, high strength adhesive, prestressed plastic, rubber sealant, dental materials etc.. At this point, it is very important to have a monomer that can expand polymerization, reduce or even eliminate the volume contraction in the polymerization process. W.J.Bailey[1,2] and other studies have found that the polymerization of spiro compounds, such as spiro carbonates and spiro esters, occurs in the process of ring opening polymerization, resulting in the expansion of the volume of the polymerization system. In this paper, a new expansion monomer 3,9- hydroxymethyl-2 -3synthesized 9- two isopropyl -1,5,7,11- four oxaspiro [5,5] eleven in two alkane, chloroethane, using BF3.OEt2 as the catalyst can double ring cationic polymerization. This monomer can be used in the modification of epoxy resin. Introduction： Epoxy resin (EP) is one of the most important thermosetting resins. Each molecule contains two or more than two epoxy groups of [3]. It is the most widely used matrix resin for polymer composites. It is a kind of high molecular synthetic resin with excellent properties. Epoxy resin has excellent adhesive properties, wear resistance, mechanical properties, electrical insulation performance, chemical stability, high and low temperature performance, and low shrinkage, easy processing, molding and low cost and so on. [4]. It has been widely used in adhesives, electronic instruments, light industry, construction, machinery, aerospace, coatings, electronic and electrical insulation materials and composite materials, [3,5]. However, the shrinkage of epoxy resin will inevitably lead to a certain residual stress when i