Premium
Polymer Effects on the Chemorheological and Drying Behavior of Alumina–Poly(vinyl alcohol) Gelcasting Suspensions
Author(s) -
Huha Marsha A.,
Lewis Jennifer A.
Publication year - 2000
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.2000.tb01497.x
Subject(s) - vinyl alcohol , materials science , polymer , hydrolysis , aqueous solution , chemical engineering , composite material , casting , polymer chemistry , organic chemistry , chemistry , engineering
A new gelcasting system based on aqueous alumina (Al 2 O 3 )–poly(vinyl alcohol) (PVA) suspensions cross‐linked via titanium ion complexation has been developed as a feedstock for bulk casting and solid freeform fabrication (SFF) routes. Its chemorheological properties, as measured by stress viscometry and oscillatory techniques, exhibited a strong dependence upon polymer hydrolysis and molecular weight. The gelation time of systems of constant PVA volume fraction (φ PVA soln ) and cross‐linker concentration decreased with increasing degree of hydrolysis and molecular weight, whereas their steady‐state elastic modulus ( G′ ) exhibited the opposite dependence. Stress evolution during drying of gelcast layers was measured in situ using a controlled‐environment, cantilever deflection apparatus. Both the maximum and residual drying stresses increased with increasing degree of hydrolysis, with only a modest molecular weight effect observed.