The invention discloses a production method of a composite
fiber cement board, and belongs to the technical field of building materials. The production method comprises the following steps: mixing
microcrystalline cellulose with a
sodium hydroxide solution, cooling the obtained solution, adding a precooled
urea solution, stirring and mixing the obtained solution, centrifuging the obtained solutionto obtain a
microcrystalline cellulose solution, dropwise adding an etherifying agent to the
microcrystalline cellulose solution, performing constant-temperature stirring and reacting, cooling the obtained solution, adding
urease and a
calcium nitrate solution, continuing a reaction, concentrating the obtained reaction solution,
drying the concentrated reaction solution to obtain etherified
microcrystalline cellulose, performing a constant-temperature and constant-pressure reaction on the etherified
microcrystalline cellulose and a
sodium methoxide solution, cooling the obtained reaction solution, adding
chloromethane, performing a constant-temperature and constant-pressure reaction, carrying out reduced pressure concentrating,
drying the obtained concentrate to obtain modified
microcrystalline cellulose, mixing
cement, the modified microcrystalline cellulose, a
water reducer and a
defoamer, carrying out injection molding, and curing the molded mixture to obtain the composite
fiber cement board. The composite
fiber cement board obtained in the invention has excellent mechanical properties.