Strong Yet Tough Transparent Paper with Superb Foldability.

Area of Science:

• Materials Science
• Biomaterials Engineering
• Sustainable Chemistry

Background:

• Transparent paper from wood fibers offers a sustainable alternative to plastics.
• Challenges remain in fully characterizing and optimizing the mechanical properties of wood-based transparent papers.
• Developing high-performance transparent paper requires innovative fiber modification techniques.

Purpose of the Study:

• To prepare a strong, tough, and highly transparent paper from wood fibers with enhanced mechanical properties.
• To investigate the role of fiber structure modification in improving paper performance.
• To provide a viable route for wood-based materials to replace nonrenewable plastics.

Main Methods:

• Utilized microwave-assisted deep eutectic solvent (DES) pulping (choline chloride/lactic acid) to isolate spruce wood fibers.
• Partially disrupted the S1 layer of fibers, creating microfibrils to enhance cellulose accessibility.
• Applied carboxymethylation treatment to create uniformly swollen carboxymethylated wood fibers (CM fibers) for improved inter-fiber interactions.

Main Results:

• Achieved 90% light transmittance at 550 nm.
• Demonstrated superior mechanical properties: folding endurance > 26,000, tensile strength of 248.4 MPa, and toughness of 15.6 MJ m⁻³.
• The modified fiber structure and improved interactions led to enhanced paper performance.

Conclusions:

• Successfully manufactured a high-performance transparent paper from wood fibers.
• The developed method offers a promising strategy for creating sustainable materials with properties competitive against plastics.
• This advancement opens possibilities for wood-based materials in applications traditionally requiring high-performance plastics.