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A modified phenol-formaldehyde (PF) resin was synthesized under alkaline condition in varying proportion of borax up to 21% (w/w). All the prepared resin were characterized by free phenol content, free formaldehyde content as well as hydroxymethyl content. It was proved by Fourier transform infrared spectrometer (FTIR) that B-O bond had been successfully introduced into the structure of PF resin. Thermo gravimetric analyzer (TGA) and different scanning calorimetry (DSC) were used to characterize the thermodynamic characteristics of the PF resin. The result showed that when the mass fraction of borax was 9wt.% of PF resin, the heat resistance was the best and the curing temperature of the modified PF resin was higher than that of the unmodified PF resin.

In this work, we concentrate on the preparation of oxidized starch modification reagent by enzymatic hydrolysis pretreatment, preparation of the urea-formaldehyde resin with low toxicity. The performance of modified urea-formaldehyde resin depend on the oxidation degree of oxidized starch and whether using enzymatic hydrolysis pretreatment or not. 100-PH9-HOS(the starch enzymatic hydrolysis then oxidized in 100°C with pH 9) synthetized modified urea-formaldehyde resin (100-PH9-HOS-UF) only with a free formaldehyde content of 0.14%, the lowest formaldehyde emission of 0.6078mg/L. Infrared spectroscopy test results show that samples at 3350cm-1 p-hydroxyl hydrogen bonds of association half-peak width minimum hefeng, amino-hydroxy hydrogen bond of association that samples are the weakest and with maximum cross-linking degrees; The modified urea-formaldehyde resin by oxidized starch curing properties of impact factors show that: the deeper drgree of oxidation, the higher curing temperature and the lower enthalpy.

The formaldehyde emission test of MDF decorated with a paper sheet impregnated thermosetting resin was done under the simulated indoor conditions. The results showed that formaldehyde emission decreases after being placed under the condition of high temperature and relative humidity. In addition, the formaldehyde emission of medium density fiberboard with paper impregnated thermosetting resins (MDFPs) increases along with the increase of furniture-bearing ratio.

Simulation of the common application environment of furniture were carried out, effects of different processing methods, storage time and airtight time were investigated. The results showed that the longer storage time or shorter airtight time was, the lower formaldehyde emission was. While the shedding of edge banding and metal connecting parts would increase the formaldehyde emission.

Low formaldehyde emission and high bonding strength were two basic criterions of a good urea-formaldehyde resin adhesive (UFRA). In our study, melamine modified methylolurea solution (MUS), was synthesized and used as modifier for UFRA. The bonding strength and formaldehyde emission of urea-formaldehyde resin adhesives(UFRA) were influenced by some factors such as F/U molar ratio of the main resin, F/U molar ratio of modifier, melamine content, mixing ratio of main resin with modifier, which were investigated by a series of single-factor experiments. The results showed that the best adhesive bonding strength of UFRA was 0.93MPa and the lowest formaldehyde emission was 0.43mg / L, when F/U molar ratio of the main resin was 1.5, F/U molar ratio of the MUS was 0.5, the mass fraction of melamine addition level was 5wt.% of MUS, and the mixing mass ratio of methylolurea solution (MUS) to the main UF resin was 20:80.

The phenol-melamine-urea-formaldehyde (PMUF) cocondensed resin adhesive was prepared by using phenol, urea, melamine and formaldehyde as reactants. It was characterized by 13C NMR and the results indicated that the PMUF could reduce the content of free formaldehyde, and it could make wood-based panel with high water resistance and weatherability. Sodium carbonate (Na2CO3) was able to shorten the curing time by 40% when applied to the plywood process. The addition of Na2CO3 as the curing accelerator of a PMUF had little influence on the bonding strength of waterproof layer and could shorten the hot-press time.

Hexamethoxymethyl melamine (HMMM) was used to modify UF resins to obtain good performance with low formaldehyde emission. The effect of urea to formaldehyde ratio, HMMM content on the properties of UF resin was studied in detail. The results suggested that urea to formaldehyde ratio to be 1:0.9 and 20% HMMM content is the optimum formulation to afford desired UF resin. The viscosity, solidification time, bond strength and formaldehyde emission of the modified UF resins were also studied. The results revealed that the performance of the modified UF achieved the chinese standard.