Skip to main content

The Science and Technology of Long Chain Branching in Polyolefins and their Process Control

Objective


The project exceeded expected level and quantity of deliverables in most aspects, especially in the development of a suite of model materials and conceptual/theoretical tools for modelling and interpreting LCB rheology. Fewer industrial resins were designed than originally intended, but this enabled more careful planning and execution than would otherwise have been the case. The extensional rheology and neutron scattering were carried out on fewer samples than originally intended. Several very exciting particular results have emerged - in particular a new analytical method "dilution rheology" emerging from the project has caused considerable global interest. It also proved possible to calculate the rheology of certain industrial LCB polymers from the reactor conditions via full molecular structure statistics.
However, the achievements would have fallen well short of those planned had the imposed financial cut from the commission not been made good by other financial resources of the partners. It is therefore not possible to credit the commission with 100% of the exciting and applicable outcomes of the project.
In more detail
* A successful new industrial polyethylene resin was designed, extruded into film and tested at the downstream users' site, showing enhanced properties.
* An extensive suite of model polymers was synthesised, and theoretical models developed to predict their behaviour in linear and non-linear flows, including the first model able to capture all the facets of the strange behaviour of LCB melts.
* A unique neutron-scattering flow cell was designed and build, and used to measure molecular deformation in extensional flows - raising new scientific questions on melt structure under strong deformation.
A toolbox of methods was delivered for both forward rheological prediction and reverse analysis of LCB structure in commercial resins, and tested extensively on model and industrial materials of the project.
Objectives and content
This project will develop new science and technology for
product innovation in the commodity-product polyethylene
film industry in Europe. It brings together two
elements:
A unique Europe-wide scientific expertise in structureproperty relations of branched polymer melts, represented
by an academic team which includes synthesis, bulk and
molecular physical analysis and theoretical modelling.
The technological capacity to produce for the first
time bulk quantities of polyolefins of designed molecular
structure afforded by the new metallocene catalysis
technology. This is represented by a vertical 3-industry
partnership of producer, processor end-user, all R&D and
market leaders in the field.
The aims are to put in place by the end of the project
new analytical techniques and modelling capability, which
may be used to develop the next generation of tailored
polymers 3-5 years later. These techniques will be
mainly extensions of novel rheological methods, together
with supporting molecular modelling. The new polymers
will have controlled processing and final properties,
enabling thinner film to be used than at present for many
bulk packaging applications, giving market and
environmental advantages. Initial target structures
identified within the project will be tested for
processing and end use by the "vertical" industrial
partnership.
The technical programme works via a parallel study of
synthetic "model" polymers of exact structure, testing
their modelling by rheology and neutron scattering, and
industrial polymers of less well-characterised structure.
Expertise developed with the model system is transferred
to the industrial scale materials.
The science and technology is pre-competitive in that the
industrial partners would not engage in the fundamental
molecular science at this stage without EC support, but
with it the time-to-market of new advanced plastics for
designed processing is likely to be greatly shortened.
The technology is particularly relevant to the European
market, where the stress is on flexibility of polymer
processing machinery.
The higher total cost than anticipated within a BR
Programme is justified because:
the project has exceptional European impact and
dimension (see sections 7 and 8),
we already know that it is perceived as possessing the
very highest technical merit,
there is extra value in maintaining the momentum of the
project and making contact with related programmes by
relaunching it now,
previous referee's advice commends it as a "basic
research" project,
the total cost to the EC is no higher than in many
projects below the limit due to the 50% cost recovery of
a major academic partner (partner 3).

Funding Scheme

CSC - Cost-sharing contracts

Coordinator

University of Leeds
Address
.,Woodhouse Lane
LS2 9JT Leeds
United Kingdom

Participants (5)

DOW Benelux NV
Netherlands
Address
5,Herbert Dowweg
4530 AA Terneuzen
Forschungszentrum Jülich GmbH
Germany
Address
Wilhelm-johenstraùe
52428 Jülich
UNIVERSITY OF SHEFFIELD
United Kingdom
Address
Brook Hill
S3 7HF Sheffield
UPM-Kymmene Corporation
Finland
Address

37601 Valkeakoski
Windmfller & Holscher Kommanditgesellschaft
Germany
Address
50,Munsterstrasse
49525 Lengerrich