Lyocell Fiber-Reinforced Cellulose Ester Composites-Manufacturing Considerations and Properties

Biodegradable thermoplastic composites were prepared using high modulus lyocell fibers and cellulose acetate butyrate (CAB). Two reinforcement fiber types: fabric and continuous fiber tow were used. Fabric had advantages of uniform alignment and easier processing, but lacked the use as a unidirectional reinforcement and a continuous method of matrix application. Three different matrix application methods were screened for both fiber types. Matrix application by suspension of particles in water was not feasible because of particle sizes > 15 &micro m. The other disadvantages were high moisture absorption during matrix application and void formation during consolidation. Melt processing technique using alternating sandwich structure of fabrics and CAB films produced composites with impressive appearance, low void contents and low moisture absorption. However, SEM results revealed interfacial failure and extensive fiber pull out. Relatively larger fiber and matrix regions were present on the scale of 10^-3m. Solution prepregging technique using methyl ethyl ketone (MEK) as a solvent for CAB and continuous fibers as reinforcement produced composites with uniform matrix distribution, high tensile strengths and high modulus, and even wetting of fibers by CAB. A maximum tensile modulus of 21.5 GPa and a maximum strength of 251.7 MPa were achieved for a continuous fiber reinforced composites at a volume fraction of 66.5% compared to 0.8 GPa and 76 MPa for the matrix, respectively. Void contents and water absorption were relatively high compared to comparable carbon fiber composites.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Chemical Engineering

Department dc:contributor.department

Chemical Engineering

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

1999

Author dc:creator

• Ghosh, Indrajit

Chair dc:contributor.committeechair

• Glasser, Wolfgang G.

Committee members dc:contributor.committeemember

• Frazier, Charles E.
• Davis, Richey M.

• biodegradable composite
• cellulose
• cellulose ester
• fiber
• cellulose acetate butyrate
• lyocell
• solution prepregging
• high modulus.
• Composite

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Dc Identifier Other

etd-091199-201727

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/35023