Time：2018/9/14 Check：53
Unsaturated polyester resin, usually by unsaturated or saturated dibasic acid dibasic acid glycol unsaturated glycol polycondensation of with ester bond of linear polymers and unsaturated double bond. Usually, polyester melt polycondensation reaction was conducted in 190 ~ 220 ℃, until the desired acid value (or viscosity), at the end of the polyester melt condensation reaction, add a certain amount of vinyl monomer, match into sticky liquid, the polymer solution is called unsaturated polyester resin.
Curing of unsaturated polyester resin is a function of linear macromolecular through crosslinking agent, a stereoscopic shape network process, but doesn't consume all the active double bond in resin curing process and curing degree of up to 100%. It is difficult to achieve full meaning of the resin curing degrees. Late the cure reaction of the reason for this is that, the system viscosity increases sharply divided the diffusion and hampered. Normally only according to the material performance stable, is considered to be cured completely. Impact on the performance of glass fiber reinforced plastic resin in the curing degree. The higher the curing degree, the mechanical properties of glass fiber reinforced plastic products and give full play to the physical and chemical performance. (someone doing experiment, the different stages of UPR resin after curing physical testing, the results show that the bending strength as the growth of the time period of growth, has been stable until a year later. In fact, for fiberglass products have been put into use, a year later, due to aging, such as heat, light and medium corrosion etc, mechanical properties gradually decline again.)
The influencing factors of unsaturated polyester resin curing degree has a lot of, the composition of the resin itself, the amount of initiator, promoter, curing temperature, curing temperature and curing time after etc can all influence of polyester resin curing degree.
