Additive compositions for papermaking

A method of preparing a drainage-optimized additive composition for papermaking, comprising:

• I) preparing a cationic acrylamide (cAM) prepolymer having at least one predetermined physical property selected from cationic monomer content, reduced solution viscosity (RSV), charge density, and zeta potential;
• and
• II) selectively glyoxalating the cAM prepolymer by controlling the concentration of the cAM prepolymer in an aqueous media during glyoxalation to give a glyoxalated polyacrylamide (gPAM) resin having a weight average molecular weight (Mw) of at least about 5 MDa, thereby preparing the additive composition,
• wherein (II) selectively glyoxalating the cAM prep comprises reacting the cAM prepolymer (A) and the glyoxal (B) in an aqueous media and wherein:
• (i) the cAM prepolymer (A) is present in the aqueous media at an initial concentration of from about 0.9 to about 5.7%;
• (ii) the cAM prepolymer (A) and the glyoxal (B) are reacted in a dry weight (w/w) ratio of from about 75:25 to about 95:5 (A):(B);
• or
• (iii) both (i) and (ii), and
• wherein selectively glyoxalating the CAM prepolymer gives the glyoxalated polyacrylamide (gPAM) resin in the aqueous media at a solids content (%) of about X+0.3, where X is the initial concentration of the cAM. polymer (A) in the aqu cous media.

A method of preparing a drainage-optimized additive composition for papermaking, comprising:

• I) preparing a cationic acrylamide (cAM) prepolymer having at least one predetermined physical property selected from cationic monomer content, reduced solution viscosity (RSV), charge density, and zeta potential;
• and
• II) selectively glyoxalating the cAM prepolymer by controlling the concentration of the cAM prepolymer in an aqueous media during glyoxalation to give a glyoxalated polyacrylamide (gPAM) resin having a weight average molecular weight (Mw) of at least about 5 MDa, thereby preparing the additive composition,
• wherein:
• (i) the gPAM resin has a zeta potential within about 10% of the zeta potential of the cAM prepolymer (A);
• (ii) the gPAM resin has a charge density within about 10 of the charge density of the cAM prepolymer (A);
• or
• (iii) both (i) and (ii).

A method of preparing a drainage-optimized additive composition for papermaking, comprising:

• I) preparing a cationic acrylamide (cAM) prepolymer having at least one predetermined physical property selected from cationic monomer content, reduced solution viscosity (RSV), charge density, and zeta potential;
• and
• II) selectively glyoxalating the cAM prepolymer by controlling the concentration of the cAM prepolymer in an aqueous media during glyoxalation to give a glyoxalated polyacrylamide (gPAM) resin having a weight average molecular weight (Mw) of at least about 5 MDa, thereby preparing the additive composition,
• wherein the gPAM resin is present in an amount of from about 1.2 to about 6% solids, based on the aqueous media.