Through experiment, the phenomena on frost boil of roads in spring results from the forming of assembled ice layer under the road bed which water heads to during the soil s freezing in winter, from the roadbed bear strength declining due to ice s melting in spring and from the truck load.

A novel freezing polymerization method of synthesizing macroporous poly(N-isopropylacrylamide)(PNIPA) hydrogels was proposed.

The histories of experimental and theoretical development of all kinds of SMP, such as polynorbornlene, trans polyisoprene, crosslinked polyethylene and polyurethane were given and the applications of SMP in medical treatment, packaging, building, toy, autocar and equipment of alarm were presented.

And summed the histories of experimental and theoretical development of all inds of shape memory polymers,such as trans-polyisoprene(TPI),crosslinked polythylene(XLPE)polynorbornlene,polyurethane(PU),gelatin system and others.

Based on principle of shape memory, performanceand application of the polymers includingpolynorbornylene,anti-polyisorprene,styrene-butadiene copolymer and polyurethane are discussed,and the developing prospects of them are given.

Shape-memory resin is a new type of functional macromolecular material, now, the exploited varieties are polynorbornylene, homo-anti-polyisoprene, butyl-phenyl copolymer, and polyurethane.