Dissertation Defenses

Doctoral Dissertation Announcement

Candidate: Lokendra Pal

Degree of: Doctor of Philosophy

Department: Paper Engineering, Chemical Engineering, and Imaging

Title: Sustainable Barrier SBS Paperboard Coatings Using Shape Engineered Pigments and In-situ Polymerization

Committee:
Dr. Margaret K. Joyce, Chair
Dr. Paul D. Fleming
Dr. Dave E. Knox

Date: Thursday, November 16, 2006 2:00 p.m. – 4:00 p.m. Parkview Campus, Room B122

Abstract: This study concentrates on the development, application, characterization and optimization of shape engineered pigments and in-situ polymerized sustainable coatings to provide solid bleached sulfate (SBS) board with a barrier against water, water vapor, and gasses. In contrast to off-line extrusion coating with petroleum based products, conventional and in-situ polymerized shape engineered pigmented dispersion coatings were used to improve barrier, surface, optical and mechanical properties of an SBS board.

It is very important for package and disposable food service ware made from coated SBS board to maintain barrier and mechanical properties at high humidity and temperature applications. The coated SBS board should protect the foodstuff from gasses such as oxygen and water, water vapor, and also from microorganisms and other contaminants from various sources. The coated SBS board should also maintain the mechanical properties such as flexural stiffness while the end-user handles the package or disposable food service ware made from the board.

Paperboard packages are commonly extrusion coated off-machine with petroleum based products such as polyethylene, polypropylene & polyethylene terephthalate, etc. to improve its barrier against gasses, water and water vapor. Unfortunately, the recycling of petroleum based products coated on SBS paperboard is extremely difficult. Manufacturers, retailers, and consumers awareness to use environmentally friendly packaging assemblies has created a large and expanding market for renewable, recyclable and/or biodegradable materials. The need to reduce the amount of non-disposable materials is ever increasing.

Thus, the paper manufacturer’s desire to produce paperboard for barrier applications on-machine in a single run and consumer pressure to reduce the amount of non-recyclable petroleum based products, has created a need for research in dispersion coatings for barrier applications.
This study is an attempt to limit or replace the above-mentioned materials with nanostructured environmental friendly shape engineered pigments. Shape engineered pigments based barrier coatings provided significantly improved barrier and other property enhancements. The developed barrier coatings have lower water and water vapor sensitivity, and permeability to gases without affecting the mechanical properties. All these property improvements could be used to impart barrier properties to packages.