Research on the novel hybrid polymerization system of hexamethoxymethyl melamine (HMMM)-polyol-acrylate-acid has been reviewed. The hybrid system involves a condensation reaction of HMMM and free radical polymerization of acrylate

although there is no free radical initiator in the compositions．It is suggested that active methylene groups can be oxidized to the corresponding hydroperoxide through a charge transfer complex (CTC) between HMMM and O2 in the air．Catalyzed by acid

the hydroperoxide decomposes rapidly

generates free radicals and then initiates the free radical polymerization．There are some synergetic effects between the radical polymerization and condensation reaction．First

the curing rate could be enhanced greatly．Secondly

DSC trace of the hybrid polymerization system demonstrates that there is obvious energy compensation effect in the system．The released energy of the free radical polymerization of acrylate can be transferred to the endothermic condensation reaction of HMMM．Thirdly

the properties of cured film

such as mechanical properties and solvent-resistance

are gready improved．It is demonstrated that the improvement is caused by the formation of polymer alloys with IPN (Interpenetrating polymer network) structure in-situ via dynamic mechanical thermal analysis (DMTA) and transmission electron microscope (TEM)．In addition

acrylate can adjust the viscosity of the formulation and reduce the use of volatile organic compound (VOC)．To make the formulation more flexible

some new compounds containing very active methylene groups and hydroxyl group such as diethylene glycol allyl ether and diethylene glycol benzyl ether were synthesized and used as the crosslinker-initiators in the hybrid polymerization system. To increase the shelf-time of the formulation

latent acid catalysts trans-2-hydroxycyclohexyl-p-toluenesulfonate and pyridine p-toluenesulfonate

were used as the source of acid in the hybrid formulations．The application of hyperbranched polymers in hybrid polymerization system is under study．Consequently

the hybrid polymerization system of HMMM-polyol-acrylate-acid is promising to formulate a high curing rate

low solvent content

energy conservation and high quality coating．