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The effect of surface properties of Boron Nitride on polymer processability Rathod, Nimish

Abstract

In commercial polymer processing operation such as extrusion, film blowing and blow molding, product quality and production rate are limited by the appearance of flow instabilities. This flow instability is manifested as distortions on the extrudate surface (melt fracture), usually observed at high production rates. Fluoropolymers have long been used as processing aids for surface melt fracture treatment of polyolefin extrudates. Recent developments have shown that a small amount of Boron Nitride (BN) powder successfully eliminates surface melt fracture and also delays the onset of gross melt fracture. It is also observed that a combination of BN and Fluoropolymer enhances the performance of the extrusion even further. The main objective of the present work is to estimate surface properties of BN mainly surface energy and adsorption capacity to understand its influence in the performance of different grades of BN as processing aids. Based on this study, it can be concluded that surface energy plays a very important role in deciding the possible interaction between the processing aid, polymer melt and the extruding surface. It is observed that lubricious nature of BN along with an optimum balance of surface energy and polarity makes BN (grades: AS 612 and CTF5) successful in both sharkskin as well as gross melt fracture regions.

Item Metadata

Title
The effect of surface properties of Boron Nitride on polymer processability
Creator
Rathod, Nimish
Publisher
University of British Columbia
Date Issued
2003
Description
In commercial polymer processing operation such as extrusion, film blowing and blow molding, product quality and production rate are limited by the appearance of flow instabilities. This flow instability is manifested as distortions on the extrudate surface (melt fracture), usually observed at high production rates. Fluoropolymers have long been used as processing aids for surface melt fracture treatment of polyolefin extrudates. Recent developments have shown that a small amount of Boron Nitride (BN) powder successfully eliminates surface melt fracture and also delays the onset of gross melt fracture. It is also observed that a combination of BN and Fluoropolymer enhances the performance of the extrusion even further. The main objective of the present work is to estimate surface properties of BN mainly surface energy and adsorption capacity to understand its influence in the performance of different grades of BN as processing aids. Based on this study, it can be concluded that surface energy plays a very important role in deciding the possible interaction between the processing aid, polymer melt and the extruding surface. It is observed that lubricious nature of BN along with an optimum balance of surface energy and polarity makes BN (grades: AS 612 and CTF5) successful in both sharkskin as well as gross melt fracture regions.
Extent
3821744 bytes
Genre
Thesis/Dissertation
Type
Text
File Format
application/pdf
Language
eng
Date Available
2009-10-28
Provider
Vancouver : University of British Columbia Library
Rights
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.
DOI
10.14288/1.0058988
URI
http://hdl.handle.net/2429/14300
Degree
Master of Applied Science - MASc
Program
Chemical and Biological Engineering
Affiliation
Applied Science, Faculty of; Chemical and Biological Engineering, Department of
Degree Grantor
University of British Columbia
Graduation Date
2003-11
Campus
UBCV
Scholarly Level
Graduate
Aggregated Source Repository
DSpace

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Rights

For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.