+44 (0)1509 263171
Please use this identifier to cite or link to this item:
|Title: ||Processing, structure and properties of plasticized PVC|
|Authors: ||Patel, Shirish V.|
|Issue Date: ||1983|
|Publisher: ||© Shirish V. Patel|
|Abstract: ||The fusion and rheologica1 behaviour of PVC compounds play
a dominant role in the processing operations and in the development
of physical properties in the processed material. These
phenomena are governed by the complex morphological structure of PVC resin, compound composition and processing-conditions which
in turn affect the physical properties of the final product.
The fusion process of flexible PVC compounds was investigated
by a combination of several techniques. Samples with varying
states of fusion were prepared using shear-and temperature as
the processing variables in extrusion, Brabender Plastograph and
compression moulding. The degree of fusion of processed compounds
was characterized by rheology, thermal analysis, acetone test,
optical microscopy, tensile strength and extrudate appearance.
The formulation of a PVC compound has a strong influence on
the rheological properties of the melt. Hence several plasticizers
were chosen from a wide activity range and compounded at three
plasticizer concentrations of 30, 50 and 70 phr. These compounds
were processed at five different temperatures (150-20QOC) in a
Banbury mixer. They were further processed in an extruder or on a
two-roll mill followed by compression moulding.
In assessing the state of fusion a universal method was found
which could define the fusion state adequately for a given PVC
sample wbich had undergone any processing condition. Rheometer
studies were found useful in assessing state of fusion of samples
from specific formulation and processing conditions with processing
temperature as the variable. Differential scanning calorimetry
results showed that more understanding was needed to interpret
the results. However, it proved to be a versatile method in
determining the maximum temperature a sample would have reached,
irrespective of its formulation or processing history. Higher speed mixing data proved to be useful commercially since
increased plasticizer concentration gave decreased blending times.
Davenport extrusion pressure, tensile properties, morphology and
extrudate surface texture showed significant differences between'
plasticizers. An identical trend for ease of smooth extrudate
formation and its glossy texture was observed.|
|Description: ||A Doctoral Thesis. Submitted in partial fulfilment of the requirements for the award of Doctor of Philosophy of Loughborough University.|
|Appears in Collections:||PhD Theses (Materials)|
Files associated with this item:
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.