Hornification of Softwood and Hardwood Pulps Correlating with a Decrease in Accessible Surfaces.

Area of Science:

• Cellulose science
• Materials science
• Paper chemistry

Background:

• Hornification is a critical process affecting cellulosic pulp properties.
• Understanding hornification mechanisms is key to optimizing pulp and paper production.
• Previous research suggests temperature-dependent hornification mechanisms.

Purpose of the Study:

• To investigate the relationship between hornification and accessible surface area in cellulosic pulps.
• To elucidate the mechanisms of hornification in hardwood and softwood pulps.
• To assess the impact of temperature on hornification.

Main Methods:

• Cellulosic pulps (hardwood and softwood) were subjected to sequential high-temperature drying cycles to induce varying degrees of hornification.
• Water retention was measured to assess the degree of hornification.
• Accessible surface area was quantified using xyloglucan adsorption.

Main Results:

• A linear decrease in water retention correlated closely with reduced accessible surface area for both pulp types.
• Distinct linear relationships between hornification and accessible surface area were observed above and below 100 °C.
• Hornification led to reduced fiber width in softwood pulps and reduced fiber length in hardwood pulps.

Conclusions:

• The findings support the hypothesis of different hornification mechanisms occurring at different temperatures.
• Accessible surface area is a reliable indicator of hornification extent.
• Hornification impacts cellulosic fiber dimensions, with type-specific effects on width and length.