SOME STUDIES ON THE BLENDS OP POLY (VINYL ACETATE) AND POLY(ETHYL METHACRYLATE).
SOME STUDIES ON THE BLENDS OP POLY (VINYL ACETATE) AND POLY(ETHYL METHACRYLATE).
No Thumbnail Available
Date
1984-07
Authors
IBIYEYE, MARGARET KUDIRAT
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Studies have been conducted on blending of
Polyvinylacetate with Polyethylmethacrylnte.
Polyvinylacetate and Polyethylmethacrylate samples
were prepared using emulsion polymerisation method
under different conditions to obtain polymers of
varying molecular characteristics. The viscosity
average molecular weight of each polymer was determined.
Four different methods were used to assess and
characterise the type of interaction taking place in
the two polymers when blended together.
Study of the blends of PVAc and PEMA by dilute
solution viscosity revealed two types of interactions
viz PVAc - PEMA intermolecular interaction which
increases with molecular weight of PEMA and molecular
weight ratio of the polymers. This type of interaction
leads to formation of blends with co-operative forces
of stabilisation which are superior to those of the
pure polymers.
The other type of interaction is the PVAc or PEMA
intramolecular interaction which leads to independent
behavior of the two polymers, and decreases with increase
in molecular weight of PEMA and the molecular weight
ratio of the polymers.
viii
From the Melt Flow Index study of the melt form of
PEMA and PVAc blends, one form of interaction
predominates, namely the PVAc - PEMA intermolecular
interaction which increases with the molecular weight
of PEMA and therefore leads to an improvement in the
melt flow characteristics of either of the two polymers.
Also a mode of interaction has been suggested in
which PEMA acts as a surface on which FVAc is arranged,
thus improving the macromolecular arrangement in the
melt.
Mechanical study of films of the blends were
carried out on the Instron testing Machine. Two types
of interaction existed between the polymers namely the
PVAc - PEMA intermolecular interaction which leads
to blends which are strong and of superior properties
to those of the individual polymers, and the other from
weak Vander Waals forces due to the PVAc or PEMA
intermolecular and possibly intramolecular attractions
between the molecules of the polymers, leading to the
formation of inferior blends. These properties are
strongly depended on the molecular weight ratio (Mv)
for the two polymers i.e. MV
PEMA
/MV
PVAC.
Optical microscopy was also used to aid in
determining not only the presence but the connectivities
of the phases representing each polymer.
Description
A THESIS SUBMITTED TO THE POSTGRADUATE SCHOOL, AHMADU
BELLO UNIVERSITY, IN PARTIAL FULFILMENT OF THE REQUIREMENTS
FOR THE DEGREE OF MASTER OF SCIENCE IN POLYMER SCIENCE AND
TECHNOLOGY.
Keywords
STUDIES, BLENDS, POLY, (VINYL ACETATE), ETHYL METHACRYLATE).