Industry liaison program "Emulsion Polymerization"

Backgrounds and Summary

The principle of emulsion polymerization has been applied for decades in the production of polymer materials. Progress and competition have led the producers of these polymers to further optimize their products and to develop new ones. Within this context, the opportunities typically offered by dispersed (emulsion) systems have gained much interest. The latter include new methods of determining and controlling copolymer microstructure (random, alternating, block and graft copolymers) and particle morphology (core-shell, "currant bun", doublet, void, non-spherical, etc.). These developments have revealed that knowledge in some fundamental aspects of emulsion polymerization is lacking and that, generally speaking, academic researchers have strongly neglected this important area.

The above considerations have inspired the Polymer Chemistry Group at Eindhoven University of Technology (TU/e) to start an industry liaison program in "Emulsion Polymerization". The organisation set up in 1988 for this purpose is the foundation "Stichting Emulsion Polymerization" (SEP). This research organization is designed to advance basic as well as innovative research in the area of emulsion polymerization by bringing together the university and the polymer (and allied) industries.

Member companies will have the opportunity to influence the research program through their representative on the Advisory Board of SEP. Exposure to the emulsion polymer research at the participating Emulsion Research Groups (ERG) will extend the facilities and capabilities of the research establishment of the participating companies. Further details on the benefits to the industry members are given below. Participating companies will support the research program with a contribution to SEP of seventeen thousand Euro (€ 17.000) per year for minimum four-year periods.

Introduction

High performance polymeric materials often are required to possess a high modulus as well as high impact strength. This is usually accomplished by the incorporation of a finely dispersed rubbery component; examples are ABS, HIPS, rubber-filled nylon, impact resistant polycarbonate, etc. The dispersed rubber phase has to meet very high requirements with respect to, i.a. degree of crosslinking, particle size, particle size distribution, grafting, and surface functionalization. Similar considerations are valid for the effects of pigment and filler particles on the properties of polymer materials.

In copolymers, important properties like the heat distortion temperature, the decomposition temperature, and toughness do not only depend upon the molecular weight distribution, but also strongly upon the chemical composition distribution, i.e. the inter- and intramolecular distribution of monomeric units. Moreover, the chemical composition distribution of a copolymer will have a pronounced effect on its compatibility with other (co)polymers, and thus through particle morphology on product properties. Also the addition of particles with a specific core-shell morphology may lead to very high performance composite materials.

In the manufacturing of these high performance materials increasingly stringent environmental requirements will have to be met with regard to production process, product stability/durability, residual monomer content, and reuse.

The paint- and surface-coating industry shows an increasing interest in replacing the conventional solvent-based paints by water-borne (latex) paints. Beside the technological advantages during production, this move is mainly dictated by environmental arguments. The performance of water-based paints is determined by many factors. Without any claim to completeness, some important factors are:

• the chemical and microstructural properties of polymer binder particles,
• the physical and chemical condition of the particle surface,
• the morphology (core-shell), size and size distribution of the latex particles,
• the interaction between binder and pigment/filler particles,
• the stability of paint dispersions,
• rheological properties of coating dispersions,
• film formation behaviour,
• the nature of the surfactant system,
• the possibility of triggering crosslinking reactions after film formation,
• properties of the paint film, such as adhesion to the substrate, mechanical and optical properties (gloss!), resistance against chemical and physical degradation, etc.

Moreover, product properties are strongly influenced by process conditions, polymeric (micro)structure and latex behaviour in the manufacturing of latexes for i.a. paper coatings, textile finishes, adhesives, and carpet backings.

At first sight, the heterogeneous polymerization techniques required to manufacture advanced materials merely seem to add many complications in understanding and controlling the processes involved.

On the other hand, it should be realized that, apart from the technological advantages, the principle of heterogeneous (co/ter)polymerization offers unique opportunities not available in homogeneous systems. These include the intrinsic possibilities of exploiting the heterogeneity of the system to control the heterogeneity at the molecular level (co/terpolymer blockiness, monomer sequence distribution, composition drift, etc.) as well as to control the heterogeneity at the particle size (morphology) level (core-shell, compositional gradient, domain structure, IPN, surface modification, etc.).

In the past, however, emulsion polymerization has mainly been applied in an empirical manner and the understanding of the kinetic and mechanistic processes involved, model development and theoretical insights are strongly lagging behind.

The implementation of controlled radical polymerisation in emulsion polymerisation is a new and challenging area where fundamental understanding is aiding the development of new latex particles morphologies with interesting new applications.

A number of universities have a strong tradition in fundamental research on physical aspects of colloidal systems, but they usually neglect the chemical aspects and relations between reaction (process) conditions, structure (molecular as well as morphological), and properties of the resulting latexes and materials.

The chain of knowledge offered by the Emulsion Research Groups participating in SEP is unique in placing a major broad emphasis on emulsion polymerization, i.e. focuses on chemistry, reactions, kinetic and mechanistic aspects, and polymerization processes, in close relation with the resulting molecular structures, particle morphologies and product properties.

The SEP organization is designed to promote precompetitive research in the area of emulsion polymerization and emulsion polymers by bringing together the pertaining Emulsion Research Groups and interested industry partners.

Main objectives of SEP

• The "Stichting Emulsion Polymerization" (SEP) is designed to promote research as well as education in the area of emulsion polymerization by bringing together the university and the polymer (allied) industries.
• SEP will stimulate and advance application-oriented, basic and innovative research, to be conducted by the participating Emulsion Research Groups (ERG), in areas of common precompetitive interest to the industry partners.
• SEP will enhance research activities in this field of common interest, i.a. by contributing to the availability of modern experimental facilities and capable personnel, required to perform high-quality research work in the ERG.
• In doing so SEP will also create a fertile soil for bilateral collaboration between the ERG and separate industries, a construction that would allow further confidentiality.
• SEP will promote the training of M.Sc. ("Ir.") and Ph.D. students of the ERG in modern theory and practice of polymer chemistry and technology, with emphasis on emulsion polymerization.
• SEP will offer training to selected personnel from the member companies by organizing courses and seminars in the field of mutual interest.
• SEP will offer consultancy and the use of experimental facilities (both to a limited extent).
• SEP will promote a rapid transfer of knowledge and all other relevant information acquired by the ERG to participating companies.

Benefits to industry members

• Each member company may nominate a representative on the Advisory Board of SEP. Through their representative the members will have the opportunity to influence the research program of SEP.
• Exposure to the emulsion polymer research at ERG will extend the facilities and capabilities of the research establishment of the participating companies.
• The member companies may send personnel to attend the SEP-seminars, organised semi-annually. At these meetings the research results, latest advances, significant discoveries, the status of the research program, and the future plans will be presented by ERG faculty members and advanced students.
• SEP members will have rapid access to the research results and expertise acquired by the ERG within the context of the SEP research program, as well as to the non-confidential results and expertise obtained from all other research activities of the ERG. This information includes graduation reports, Ph.D. theses, scientific publications, internal reports, information on new developments and experimental techniques, information on oncoming conferences, and all other information considered of importance to SEP members.
• Company members have priority (against reduced rates) when entering into bilateral contract research agreements with the ERG, on a confidential basis if required.
• Member companies are entitled to three days of consulting per annum by any of the ERG-members without cost (except for travel expenses), on a confidential basis.
• Member companies are entitled to the use of ERG's experimental facilities (after a short introduction by ERG-members, in principle operated by the company's own personnel) at reduced rates and, if required, on the basis of confidentiality. This service will be available to SEP members by priority. However, the extent may have to be limited in regard of other research and training obligations of the ERG.
• SEP members may send selected personnel to the annual course (ca. 5 days in May/June) and to the English condensed course (ca. 3 days in May) on emulsion polymerization, given by ERG-personnel and external lecturers, without cost.
• SEP offers in-house courses as a service to the SEP-members (travel costs and housing supplied by company), for each company once every four years. Additional in-house courses at a reasonable rate can be organized.
• Emulsion related software, for modelling and controlling emulsion (co/ter)polymerization, that have already been developed and those that will be developed by the ERG during a company's membership, will be made available to the member free of charge.

Research facilities of the ERG (also available to SEP members)

• Reactors for emulsion (co/ter)polymerization. Available sizes up to 5 litres reaction volume, and up to 25 bar working pressure. Batch, semi-continuous and continuous operation. (Semi-)batch fully automated stirred tank reactor, 10 liter scale based on Belatec equipment.
• Equipment and techniques for on-line measurement and process control. Available are: GC, HPLC, Densitometry, Tensiometry, Conductometry, Raman Spectroscopy, and Reaction Calorimetry, (Mettler-Toledo RC1e-HP60 reactor).
• Particle size and particle size distribution measurements. Instruments available include TEM, Dynamic Light Scattering, Static Light Scattering, Dark Field Microscopy, Disc Centrifuge, and Capillary Hydrodynamic Fractionation.
• Cryo-TEM facilities.
• Molecular weight characterization. The equipment used includes SEC(GPC), with different detectors (UV, RI, ELSD, Viscometry, LALLS), Solution Viscometry and MALDI-TOF-MS.
• Particle morphology and (co/ter)polymer characterization. The techniques available comprise TEM including Cryo-TEM, SEM (and associated staining techniques), Ultracentrifuge, UV-, VIS-, and FTIR-spectroscopy, (co/ter)polymer crossfractionation techniques based on SEC-HPLC, NMR (300 - 500 MHz), MALDI-TOF-MS, HPLC and LC-MS (HPLC-ESI-MS, HPLC-APCI-MS) for oligomer analysis, DSC, TGA, and various Dynamic Mechanical Analyzers.
• Latex and film characterization. Tensiometry, Rheometry, Viscometry, Zeta-sizer, Surface Group Analysis (i.a. Titration), MFFT-bar, total reflection (FT)IR, Gloss measurements.
• Equipment for preparation of artificial latexes and miniemulsions. Homogenizer for emulsion preparation, ultrasound probes.
• Equipment for obtaining basic kinetic data. The techniques available comprise ESR (radical concentrations), pulsed laser equipment (direct determination of k_p), stopped-flow equipment, and pulsed electron beam equipment (determination of monomer concentration in latex particles).
• Surface/interfacial tension. Contact angle instrument (dynamic contact angle, sliding angle, etc.), surface tension of liquid (Wilhelmy plate method).
• In-situ monitoring of reaction. Confocal Raman spectroscopy, ATR-FTIR (with photocuring facility).
• Zeta-potential meter and sizing.
• Characterization of coatings, Film hardness, impact resistance, scratch resistance, etc.

ERG personnel

The Emulsion Research Groups (ERG) comprises three laboratories collaborating in the area of emulsion polymerization research.

1.   Laboratory of Polymer Chemistry (Prof. Dr. A.M. van Herk, Prof. Dr. C.E. Koning)

Programme leader: Prof. Dr. A.M. van Herk, Professor in General Chemical Engineering

Other programme members:

Prof. Dr. C.E. Koning, Professor in Polymer Chemistry and Technology;
Prof. Dr. Ir. A.L. German, Professor in Polymer Chemistry;
Prof. Dr.Ir. L. Klumperman, part-time associate professor
Dr. Ir. H. Heuts, Assistant Professor;
Mr. W.J. Kingma, Laboratory Assistant;
Mrs. R.M.W.J. Knoop, Laboratory Assistant;

Ph.D. Research Students in the relevant field: 6.

2.   Laboratory of Process Development

Process and Product Development focused on Dispersed (Polymer) Systems and Fine Chemicals Production

Programme leader: Prof. Dr. J. Meuldijk, Professor in Chemical Engineering

Other programme members:

Ph.D. Research Students in the relevant field: 3

3.   Laboratory of Materials and  Interface Chemistry (Prof.dr. G. de With)

Programme leader: Prof. Dr. G. de With, Professor in Materials Science

Other programme members:

Prof.dr. R.A.T.M. van Benthem, Professor in Coatings Technology
Dr. J. Laven, Assistant Professor;
Dr. W. Ming, Assistant Professor;

Ph.D. Research Students in the relevant field: 4.

Operational structure

The "Stichting Emulsion Polymerization" (SEP), Eindhoven Chamber of Commerce nr. S090735, acts as an intermediate between the companies participating in the industry liaison program and the University Research Groups (ERG).

The present composition of the Board of the Foundation is as follows:

Chairman                                           Prof. Dr. A.M. van Herk
Secretary                                            Prof. Dr. J. Meuldijk
Treasurer                                            Mr. G.N.M.J. Verschuren
Member                                              Prof. Dr. Ir. A.L. German
Member                                              Prof. Dr. C.E. Koning

The Advisory Board members have the opportunity to influence the direction of the ERG's research and related activities, through interaction with the members of the SEP-Board and with ERG personnel at the semi-annual SEP-seminar and at the connecting meeting of the Advisory Board.
Moreover, the Advisory Board receives the annual financial report of SEP and is entitled to examine the financial situation of SEP at all times.

Technology and know-how developed in SEP-projects is owned by SEP. All member companies are equally entitled to use the results and information developed in SEP-supported projects.
A major objective of the ERG is publication (M.Sc. reports, Ph.D.-theses, journals, lectures, etc.) of the results of the pertaining precompetitive research projects.
On the other hand, SEP will maintain in confidence and will not disclose to non-members without permission from the Advisory Board, results acquired from SEP-supported research.
SEP may decide, after consulting the Advisory Board, to patent certain findings resulting from the SEP-supported projects. Member companies then will have first opportunity to be granted a non-exclusive, royalty-free licence. Only if none of the members would be interested in obtaining a licence-agreement, SEP may offer, under certain conditions, a licence-agreement to non-members.

Industry membership is open to companies or institutes engaged in the manufacture, research, development or use of polymer dispersions and related products. The acquisition of new SEP-members will only take place after hearing the Advisory Board.

Member companies will support the research program with a contribution to SEP of seventeen thousand Euro (€ 17.000) per year (price level 2007) for minimum four-year periods.

Concluding remark: in case of any possible incompleteness or discrepancy, the text and formulations used in the official (uniform) contracts between SEP and its industry members will prevail over the information provided in the above.

For further information please contact:

Prof. Dr. A.M. van Herk, or
Mrs. C.J.W. van Os-Rovers, organisational co-ordinator
Laboratory of Polymer Chemistry and Technology
Eindhoven University of Technology
P.O. Box 513
5600 MB Eindhoven, The Netherlands
Telephone: -31 (0)40 2472840
Telefax:      -31 (0)40 2463966
e-mail:        This e-mail address is being protected from spam bots, you need JavaScript enabled to view it  
http://www.emulsion-polymerization.info

Eindhoven, May 2007