Study Of Phenol-Starch Resin And Its Moulding Materials

Phenolic resins and their moulding materials of low cost and greenness are made by replacing poisonous matters of high cost with green natural resources of low cost, which is critical in the development of the phenolic resins and plastics industry of next generation. Based on the comprehensive review of the history and the newest progress of the studies on phenolic resins and their moulding materials at home and abroad, in view of these problems how to reduce cost, poisonousness and pollution of phenolic resins and their moulding materials, the developed studies focused on the making of phenol-starch resin and its moulding materials by replacing formaldehyde and part of phenol with starch, which speedily promote the preparative technique of phenolic resins and plastics of low cost and greenness at home, increase a kind of new type products of phenolic resins and their moulding materials, establish the study base of phenol-starch and its moulding materials , and provide necessary technical store and guarantee for phenol-starch resin and its moulding materials from laboratory to realistic application.Phenol-starch resin is a new type phenolic resin of the one-step synthesis by polycondensation with phenol, starch as raw materials under catalysis of sulfuric acid. In the thesis, the effects of amount of catalyst, raw materials mass ratio, reaction temperature and reaction time on the resin synthesis were discussed, the optimum raw materials formula and synthetic technology were determined, the resin structure was characterized, the resin synthetic reaction mechanism and curing reaction mechanism were expounded, the effects of hexamethylene-tetramine use weight, molecular weight, water content, free phenol content, magnesium oxide use weight and temperature on the resin curing were analyzed, the characterization and study of the resin properties were conducted; the brittleness of phenol-starch resin were modified by nylon 6, the raw materials formula and synthetic technology of the modified resin were determined, its properties was tested. The results show that the optimum technological conditions of the resin synthesis are that the raw materials formula (mass portion) is phenol : starch : sulfuric acid = 550 : 600 : 4.95, the control parameters of time and temperature are room temperature-60℃/15min+60℃/50min+60-105℃/30min +105℃/70min+105-115℃/20min+115-165℃/120min+165℃/60min+165-130℃ /30min+130℃/30min, vacuum degree 0.08-0.09MPa for drawing liquid phenol, vacuum degree 0.04-0.05MPa for taking off waste fluid; the synthetic reaction mechanism may be that starch produces glucose, further glucose produces hydroxymethylfurfural and the polycondensation reaction takes place between hydroxymethylfurfural or glucose and phenol to yield phenol-starch resin under function of sulfuric acid catalyst and heat, the resin containing a great many of the structure of 1,2,6-benzene ring is the thermoplastic phenolic resin; it is large that the effects of amount of catalyst, reaction temperature, reaction time and phenol/starch mass ratio on the resin properties, the resin is similar in the properties to the thermoplastic phenol-formaldehyde resin, specially it has very good heat resisting property; the resin is cured speedily by hexamethylene-tetramine of 17% resin mass at over 165℃, curing reaction rate relate to amount of hexamethylene-tetramine and magnesium oxide , chemical composition of the resin, water and free phenol content in the resin and temperature, among them the greatest effect factor is temperature, and then factors are chemical composition of the resin and water and free phenol content; by comparison with the phenol-formaldehyde resin, the cost of raw materials is reduced by 24.5%, amount of waste fluid is reduced by 43.8%. The raw materials formula (mass portion) of the modified resin is phenol : starch : nylon 6 :sulfuric acid = 300 : 330 : 35 : 2.00,the control parameters of time and temperature are room temperature⁶0℃/15min+60℃/50min+60-105℃/30min+105℃/60min+105-115℃/20min+115-160℃/110min+160℃/80min+160-130℃/25min+130℃/45min, vacuum degree 0.08-0.09MPa for drawing liquid phenol, vacuum degree 0.04-0.05MPa for taking offwaste fluid; its flexural strength is increased by 22.5%, its impact strength is increased by 18.2%.Phenol-starch moulding materials are a kind of new type phenolic moulding materials prepared by the method of rolling with phenol-starch resin, hexamethylene-tetramine, wood flour, calcium carbonate, magnesium oxide, zinc stearate, stearic acid, Oil Aniline Black and ultramarine as raw materials, developed three type moulding materials are PF2A1, PF2A2 and PF2C4. PF2A1 belongs to versatile phenolic moulding materials for making articles for daily life use, PF2A2 belongs to versatile phenolic moulding materials for making insulating structural parts of low voltage electrical equipments, PF2C4 belongs to heat resisting phenolic moulding materials for making insulating parts of low voltage electrical equipments,In the thesis, the effects of raw materials mass ratio and moulding temperature on strength of their test specimens were discussed, their optimum raw materials formulas, preparing technologies and moulding technologies were determined, methods of their quality control were put forward, their properties and economic advantage were analyzed, application popularization was conducted. The results show that optimum raw materials formulas (mass portion) of PF2A1^â‘ /PF2A2^â‘¡/PF2C4^â‘¢are differently phenol-starch resin : hexamethylene- tetramine : wood flour : calcium carbonate : magnesium oxide : zinc stearate : stearic acid : Oil Aniline Black : ultramarine=37.0 : 6.4 : 48.0 : 6.0 : 0.6 : 0.6 : 0.4 : 0.5 : 0.5^â‘ / 40.5 : 6.9 : 45.0 :4.8: 0.8: 0.6 : 0.4 : 0.5: 0.5^â‘¡/ 37.0 : 6.4 :30.0 : 24.0 : 0.6 : 0.6 : 0.4 : 0.5 : 0.5^â‘¢;majorcontrol technological parameters of preparation are differently raw materials except resin mixing time≥10min,all raw materials mixing time≥50min, temperature of the working roller 85-95℃^â‘ /100-110℃^â‘¡/90-100℃^â‘¢,temperature of the idle roller 145-155℃^â‘ / 140-150℃^â‘¡/145-155℃^â‘¢,distance of the two rollers 2.3-2.5mm^â‘ / 2.2².5mm^â‘¡/ 2.0-2.5mm^â‘¢,warm-up time 4-5min, moulding materials combining batch time≥45min; quality of these products is controlled by bright outward appearance of sheet materials of moulding materials and Raschig flow properties 70-120mm^â‘ /80-120mm^â‘¡/80-120mm^â‘¢of moulding materials; major control parameters of moulding technology are differently preheating temperature 100-110℃,preheating time 10-15min, moulding pressure≥25MPa, moulding temperature 175-180℃^â‘ /175-180℃^â‘¡/180-185℃^â‘¢,moulding time 0.8-1.0min·mm^-1,exhaust≥3 times;by comparison with the same type thermoplastic phenol-formaldehyde moulding material, the cost of raw materials is reduced differently by 20.4%^â‘ / 21.4%^â‘¡/20.9%^â‘¢.The properties of PF2A1 come up to the national standard of raw versatile phenolic moulding materials A1,specially its thermal deformation temperature 170℃surpass greatly the national standard, insulating resistance 5.0×10¹²Î©,dielectric strength6.7MV·m^-1,dielectric loss tangent 0.03, red heat resistance 14s are excellent, it shows excellent electric properties in moist environment, and it excels obviously original similar phenolic moulding material in impact strength, thermal distortion temperature, insulation resistance and dielectric strength; the properties of PF2A2 come up to the national standard of raw versatile phenolic moulding materials A2, specially its thermal deformation temperature 171℃,insulating resistance 3.0×10¹²Î©,dielectric strength 5.9MV·m^-1,dielectric loss tangent 0.03 surpass greatly the national standard, the red heat resistance 15s is excellent, it shows excellent electric properties in moist environment, and it excels obviously original similar phenolic moulding material in thermal distortion temperature, insulation resistance and dielectric loss tangent; the properties of PF2C4 come up to the national standard of raw heat resisting phenol-formaldehyde moulding materials C4, specially its thermal deformation temperature 174℃,red heat resistance 11s, insulating resistance 6.0·10¹²Î©,dielectric strength 6.7MV·m^-1 surpass greatly the national standard, the dielectric loss tangent 0.03 is excellent, it shows very good electric properties in moist environment, and it is about equal to original more high-grade PF2C3 in flexural strength, thermal distortion temperature, insulation resistance and dielectric strength. Suitable hexamethylene-tetramine/resin, wood flour/resin mass ratio and moulding temperature are keies that test specimens obtain high strength.The industrialization design of phenol-starch resin and its moulding materials were studied. Based on the design demands, i. e. production capacity 410t·a^-1 resin and 1000t·a^-1 moulding material, work-time 24h·d^-1 and work-day 250d·a^-1,production methods of intermittent method and continuous method, the design contents including raw materials consumption quota, installations and layout, plant buildings, water, electricity and gas, posts and men, products quality standard and factory test items, investment estimate, the effluents treatment, et al were made. In disposing synthesis distillate fluid of phenol-starch resin, a new method was explored out, which 90.16% phenol is recovered by cooling crystallization and remaining fluid is made into disinfectant and preservative belong among type phenolic. Application popularization proves that the industrialized design has a lot of characteristics, and it is a feasible design.