How can low molecular polyamide resin be used?
Low molecular polyamide epoxy resin with good compatibility, not volatile, for a long period, low shrinkage of cured (<0.03%), good dimensional stability, excellent electrical performance, good water resistance, heat resistance and solvent resistance but worse. Almost non-toxic, does not irritate the skin and mucous membranes. Although low molecular polyamide can cure epoxy resin at room temperature, it takes a long time and the reaction is not complete. The reaction is only complete at 60 degrees celsius. When the room temperature is lower than 0 degrees, low molecular polyamide is difficult to react with epoxy resin. It can be added 1~3 parts of DMP-30 or 3% ~ 5% phenol (or two methylamine ethanol) to promote the curing reaction and shorten the curing time.
Low molecular polyamide, also called amino polyamide. The molecular weight of 1000~1500, light yellow viscous liquid density (75 C) fand 0.92~0.96g/cm. The amine value is 230~260mg KOH/g. Viscosity (75 DEG C) 3000~1000mPa.s. The composition of low molecular polyamide is complex, containing primary amine, secondary amine and amide group. It can cure epoxy resin at room temperature, and has good adhesion to metal, glass, ceramics, wood and so on. Low molecular polyamide molecules also have a longer aliphatic carbon chain, which can play an internal toughening effect, so that the cured epoxy resin has a certain toughness, therefore, low molecular polyamide is both a curing agent and a toughening agent. Amine value is the indication of low molecular polyamide activity. The higher the amine value is, the greater the activity is, and the reaction speed with epoxy resin is fast, the dosage is little, and the application time is short. Vice versa。
200 low molecular polyamide used as a toughness curing agent for epoxy resin adhesive. The reference dosage is 50~100 parts. The curing conditions are /7d or 65 /3h at room temperature. When the E-51/200=100/55 (mass) 25~O cured 7d, the thermal deformation temperature was 77~80 DEG C; if E-51/200=100/50, adding 3.8 parts of two amino benzene, 150~C/4h curing, the thermal deformation temperature of the cured material was 104~C. Heating and curing can effectively improve the physical and mechanical properties of the cured products. For example, the cured parts 23~C/16h+100~c/2h, the thermal deformation temperature of the cured products is 118 degrees, and the tensile strength is 32MPa. 200 low molecular polyamide is also used as tackifier for PVC sols. It can be used as epoxy resin curing agent, epoxy resin 100 parts, low molecular polyamide resin 100--150 parts
