Scholarly
    Communications Project


Document Type:Master's Thesis
Name:Indrajit Ghosh
Email address:ighosh@vt.edu
URN:1998/00788
Title:BLENDS OF BIODEGRADABLE THERMOPLASTICS WITH LIGNIN ESTERS
Degree:Masters of Science
Department:Wood Science and Forest Products
Committee Chair: Wolfgang G. Glasser
Chair's email:wglasser@vt.edu
Committee Members:Richey M. Davis
Charles E. Frazier
Keywords:Biodegradable, polymer, blend, miscibility, compatibility lignin, ester, cellulose, polycaprolactone, starch, polyhydroxybutyrate, cellulose acetate butyrate
Date of defense:April 22, 1998
Availability:Release the entire work immediately worldwide.

Abstract:

Thermoplastic blends of several biodegradable polymers with lignin (L) and lignin esters were prepared by solvent casting and melt processing. Among the biodegradable thermoplastics were cellulose acetate butyrate (CAB), poly-hydroxybutyrate (PHB), poly-hydroxybutyrate-co-valerate (PHBV), and a starch-caprolactone blend (SCL). Lignin esters included acetate (LA), butyrate (LB), hexanoate (LH), and laurate (LL). Blend characteristics were analyzed in terms of thermal and mechanical properties. The results indicate widely different levels of interaction between two polymer constituents. Melt blended samples of CAB/LA and CAB/LB were compatible on a 15-30 nm scale when probed by dynamic mechanical thermal analysis, and the glass transition temperatures of the blends followed Fox equation, whereas those of CAB/LH and CAB/LL showed distinct broad transitions on the same scale. Melt blending produced well dispersed phases whereas large phase separation evolved out of solvent castings. Crystallinity and melting points of PHB and PHBV were affected by the incorporation of lignin component, revealing some interaction between the blend constituents. Blends of SCL with L and LB revealed significant effect on crystallinity and melting temperatures of poly-caprolactone component, revealing polymer-polymer interaction between SCL and lignin components. An increased degree of crystallinity was observed in the case of higher-Tg L compared to lower Tg LB. Improvememt in modulus (and in some cases strength also) was observed in almost all blends types due to the glassy reinforcing behavior of lignin.

List of Attached Files

CHAPTERI1.PDF CHAPTERII1.PDF CHAPTERIII1.PDF
CHAPTERIV1.PDF CHAPTERV1.PDF CONTENT2.PDF
VITA3.PDF


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