| 摘要 |
A process is provided for preparing a graft polymermodified cellulose pulp filler from cellulose sulfite pulp having an R18 value greater than 80%, which comprises adding to the pulp a redox initiator; washing the pulp with water having a pH below 5 in an amount sufficient to adjust the redox initiator cation content to within the range from about 5 to about 1000 ppm of cellulose sulfite pulp; adding hydrogen peroxide in an amount to provide within the range from about 0.1% to about 4% H2O2 by weight of the sulfite pulp; and then reacting the pulp with at least one monomer having the formula: <IMAGE> in which: R1 is hydrogen or methyl; and R2 is selected from the group consisting of nitrilo -CN, <IMAGE> and COOR3 groups, wherein R3 is selected from the group consisting of methyl, ethyl, n-butyl, isobutyl and 2-ethylhexyl; at a temperature at which grafting of the monomer onto the cellulose polymer molecule proceeds but below about 70 DEG C. for a time less than twelve hours under an inert atmosphere in a grafting ratio within the range from about 1 to about 40% and an average degree of polymerization within the range from about 20 to about 4000; and then recovering the graft polymer-modified cellulose sulfite pulp. The resulting cellulose pulp is adapted for use as a filler for thermosetting resins, imparting to the resins increased impact strength and structural strength, improved resistance to heat distortion and shrinkage, and decreased water absorptivity. |
