Title Promoter Affiliations Abstract "Plast-i-Com: Efficientreuse of contaminated polymers and polymer blends through compatibilisation andstabilisation" "Isabel De Schrijver" "R&D Plastic Characterization, Processing & Recycling" "Project goalsOne of the biggest challenges of the industry is to produce in a sustainable way. As a consequence, the reduction, re-use, and upgrade of waste is becoming increasingly important. Moreover, the raising prices of raw materials are pushing the industry to economize on raw materials and energy. Some companies are already experienced in the re-use of intern polymer waste without a significant downgrading of mechanical properties. However, it becomes more difficult when companies have to recycle waste which might be contaminated by amounts of other polymers. In these cases, the recyclates often demonstrate poor mechanical properties, since most polymers are not compatible and therefore difficult to mix homogeneously and with a well-defined fine distribution in one another. In other cases, the presence of another polymer can lead to a severe degradation due to the instability of some materials at high temperatures or a catalytic effect of contaminants on further degradation. Detection of impurities, sorting and separation of different polymers makes the recycling process more expensive and rarely offers a 100% guarantee on the removal of all impurities. Activitites and results Because of the unsatisfactory quality of mixed recyclates, they are recycled into less valuable products (downgrading) or not recycled at all. In the latter case, waste is e.g. deposited into landfill or incinerated with or even without energy recovery. A route to improve processability and to optimize the polymer quality is offered by the so-called “compatibilization”. Polymer blends can be compatibilized by creating an interphase interacting with both polymer phases. Mostly copolymeric compatibilizers or even reactive compatibilisers are proposed. Although these principles have already been known for decennia, compatibilisation is hardly applied on an industrial scale, and certainly not in the processing of recycled polymers. Looking at plastic waste, many streams consist of polymers which are immiscible or so-called not-compatible. Within the project ‘plast-i-com’, it was evaluated whether specific additives, called compatibilizers, could be used to convert non-usable, ‘ready-to-incinerate’ streams into more valuable recyclate materials. This evaluation was approached from three different angles. First of all, a theoretical approach was applied, wherein chemical models were used to predict the compatibilizing efficiency of additives for the studied blends. To this end, solubility parameters were estimated for the polymers of interest, based on the Hoftyzer-Van Krevelen method. Secondly, experimental work was performed to evaluate the actual performance of the additives in different polymer blends. Processing techniques such as injection moulding and textile extrusion were used to produce the desired test samples, whereafter mechanical testing could be performed. Finally, in a third step, numerical simulations were performed of the polymer processing of (non-)compatibilized blends, either in injection moulding or extrusion, using flow and thermal behaviour properties as input data. Based on the company’s interest, different market-relevant blends were selected for evaluation, including polyolefin (PO) blends, PET- and PA contaminated PO blends, PMMA-based blends, as well as other more niche blends. For the polyolefin blends, it seemed that ethylene copolymers were most effective to increase the mechanical properties, whereas for the PET and PA-based blends reactive compatibilizers such as glycidyl methacrylate- (GMA) and maleic anhydride- (MAH) based compatibilizers proved to be very successful. For PE/PA blends for example, the PA contamination resulted in a 4 times lower impact strength compared to pure PE material. On the other hand, as also predicted by the chemical models, MAH-based compatibilizers could increase the impact strength with 200% compared to the non-compatibilized blends. Chemical modelling also showed that for the PP/PET blends the most suitable compatibilizer candidate is not available on the market yet. Nevertheless, existing grades are able to increase the mechanical properties, although to a lesser extent compared to the PE/PA blend. In general, it could be concluded that compatibilizers positively affect the elongation and impact properties of the blends, as well as the morphological distribution of the contaminant phase inside the polymer matrix. The material stiffness on the other hand was most of the times affected in a negative way. In an attempt to restore the stiffness losses, nucleating agent were evaluated, but they only seemed effective in case of virgin non-compatibilized blends. It should also be emphasized that the material source (virgin, post-industrial vs. post-consumer grades) has a significant influence on the final compatibilization success. Next to the mechanical and morphological properties, compatibilizers could also contribute to the esthetical performance of the polymer blend. Apart from evaluating the recycled blends on an end-product performance level, their stability on a processing level could also be considered. In the current project, a research strategy was developed for a company specific case to understand the acceptable variations in viscosity to still end up with the desired end-product quality after injection moulding." "Development and Application of Polymeric Membranes for CO2 Separation" "Bart Van der Bruggen" "Process Engineering for Sustainable Systems Section" "In this study, two high performance commercial polyimide polymers, Extem and U-Varnish, and an ultra-performance polyamide-imide polymer, Rhodeftal, were selected to be employed as new materials for the preparation of membranes for CO2 separation. The phase separation behaviour of Extem/water/solvent systems for various solvents and Extem/NMP/non-solvent systems for different types of coagulants was investigated. Ternary phase diagrams were constructed based on cloud point data obtained by titration at room temperature. N methyl-2-pyrrolidone (NMP), dimethylacetamide (DMAc), dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) were employed as solvent and water was used as coagulant. The morphology of the membranes prepared from Extem/solvent/water systems (except Extem/DMSO/water) showed a finger-like sub-layer, while a sponge-like structure was observed for the Extem/DMSO/water system, which was unexpected. Water, methanol, and glycerol were employed as coagulants and NMP was selected as solvent. Using methanol as coagulation medium resulted in a thick dense layer over a macroporous sub layer, while a fully sponge-like structure with microporous skin layer was obtained for the Extem/NMP/glycerol system. In order to explore the source of these unexpected observations, several parameters that can have an effect on the membrane morphology such as binary interactions between solvent/non-solvent, heat of mixing, viscosity and diffusion rate, were thoroughly studied. It was found that in the Extem/DMSO/water system, due to the higher viscosity of the casting solution along with the lower diffusion rate, the solvent exchange process occurs at a lower rate compared to other systems, which has led to delay demixing.The performance of selected polymers in terms of plasticization was analyzed by measuring the permeability of pure CO2 at 35 oC and pressures up to 20 bar. The results showed that Rhodeftal has the highest resistance to plasticization among all tested polymers because of strong intra-molecular interactions between adjacent chain segments. In order to better understand the plasticization phenomenon, the sorption of CO2 in selected polymers was calculated by using a mathematical model based on statistical analysis. In order to improve the gas separation performance of the selected polymers, they were blended with some commercial polymers such as Matrimid and Torlon. The miscibility, inter-molecular interactions, thermal stability and crystallinity (d-spacing) of membrane blends were investigated by different analytical techniques such as DSC, FTIR and XRD. The characterization results indicated that Extem/Torlon and Extem/Matrimid do not form a miscible pair in all studied compositions, while Extem/U-Varnish and Matrimid/Rhodeftal constitute miscible polymer blends. The separation performance of membranes synthesized with these blends was investigated for a gas mixture containing 15% vol. CO2 (balanced with N2). In the case of partially miscible blends, the selectivity significantly increased, while the permeability decreased. In the case of miscible blends, the permeability and selectivity range fall between those of the pure polymers, which was expected.Finally, the HSP was employed to study the miscibility of two polymers based on polymer-polymer interaction and to find a suitable solvent for both polymers. The results revealed that the calculation of the HSP based on individual solubility parameters can predict the miscibility of two polymers better than the total solubility parameter; it was found that the total solubility parameter is not able to predict the miscibility between polymers successfully. DMF showed the highest affinity with all studied blend polymers, and thus it was used for the preparation of blend solutions." "Production of Potable Water for Small Scale Communities using Low-Cost Filtration Membrane" "Bart Van der Bruggen" "Process Engineering for Sustainable Systems Section" "The use of ultrafiltration (UF) technology in treating groundwater for the supply of potable water in the impoverished rural Tshaanda village is demonstrated in this dissertation, along with the potential of using novel membranes derived from plastic waste. The technical and administrative processes critical for the successful installation of the pilot plant were developed. Given the rural nature of Tshaanda (the study area), the cultural and traditional protocols were observed. Preliminary results of the water quality of untreated water and the permeate are presented. Escherichia coli in the untreated water during the dry season (i.e., June & July) was 2 cfu/100 ml and" "Plasticised: Innovation inbiopolymerapplication by using optimized plasticisers and new processingtechniques " "Brecht Demedts" "R&D Textile functionalisation and surface modification" "Goals Both textile extrusion (fiber, monofilaments, multi-filaments, tapes) and plastics companies (foil, profile, injection molding) can implement the extrusion formulations in their productions. The newly to be developed coating formulations will become available for companies active in coating, finishing, impregnating and printing on various raw materials. Not only textiles but also applications on metal, plastic, paper or cardboard are eligible. An important input and valorization potential is also provided for companies from the preliminary stage, namely producers of biopolymers, potential (bio) plasticizers, other additives, formulators. Targeted demonstration cases will demonstrate industrial usability for company-specific applications. PLA is a bio-based polymer that has been rising sharply in production volumes and applications in which it is used in recent years. PLA, however, also exhibits negative properties of which the high rigidity and especially brittleness at temperatures below the glass temperature (Tg) is one of the most important. For certain applications, this brittleness is an important obstacle to achieving a broadening of employability. Plasticizers in particular have the potential to absorb the brittleness of PLA. The core objective within PLAsticized is to develop optimized plasticizer formulations in function of the application and to apply them in both existing PLA applications and in newly developed applications within the coating, printing and hot-melt technology. Both an improvement in the user characteristics and a far-reaching broadening of the usability of the renewable PLA raw materials are targeted. Within PLAsticized, the selection and usability of optimized plasticisers for PLA is mapped for extrusion of yarns, films, coatings on textiles and injection molded products as well as their effects on Tg, flexibility and related properties. The impact on the processing and all quality and use parameters such as paintability, maintenance options, migration parameters, UV stability, fire resistance is determined and this in function of the specific targeted applications. This forms the basis for providing specific advice on implementation in the broad domain of the melt processing applications for PLA Applications where TPS or mainly PO are currently being used are also being targeted New extrusion applications for the plasticized PLA such as for extrusion coating on yarn or fabric level or on metal wires are being targeted, for which PLA offers a potential alternative for some PVC as PO applications In addition, new application techniques and application domains are being developed, in which the use of plasticizers is crucial.Dispersions of PLA powders in water and plastisol will be evaluated in various coating techniques (dip coating, squeegee coating, possibly foam coating). ing). The addition of plasticizers will lead to easier and more homogeneous blending (gelling) to a dense coating layer. Such formulations are also eligible for use via printing technology. Such PLA applications offer a potential alternative to some PVC, PU or acrylic coatings. Flexible low-melting plasticized formulations are also evaluated for their usability for hot-melt applications that can be used as an adhesive layer or a finishing layer.Activities and results During the first project years, the focus was primarily on identifying plasticizers for PLA. Because the project studied different product types, this was realized for different PLA grades. These were semi-crystalline PLA types for application extrusion and amorphous types for coating applications. Important differences can also be found in the process parameters. For extrusion, for example, more attention was paid to validating the thermal stability, so that process processing during compounding and extrusion was guaranteed for a longer period of time at high temperatures, while for coating applications the stability of the coating pastes was also mainly considered. A compatibility study with PLA was also conducted for the identified plasticizers, followed by migration tests. This provided an overview of which types of plasticizer are better suited for which processes and about the stability of the products. Specific attention has been paid to the characterization of the obtained plasticized materials. For yarn applications, these were mainly dimensional stability, elongation at break and tensile strength, while for coating applications, an evaluation of flexibility and durability (washing, abrasion) was studied. This was done on the basis of cyclical flexibility tests and microscopy. These techniques are complementary because sometimes flexible PLA coatings with good visual scoring showed microscopic micro-cracks. The coating component of the project was very ambitious. At the start of the project, there was no worldwide example of PLA coated textile articles. Only extrusion coating for cardboard (drinking cups) was available. All possible processing routes were therefore tested during the project. These were hot melt coating, water-based emulsions, solvent-based coatings and plastisol coatings. From thorough characterization it was decided that mainly hot melt coating and plastisol coatings showed promising results. The choice for this is obvious. Hot melt coatings are an environmentally friendly alternative to coating processes, but had the disadvantage that prior compounding with plasticizers is required and the viscosity during processing is on the high side for conventional hot melt installations. For future projects we therefore look with interest at the extrusion coating application. This is currently not yet applied in the Belgian textile industry, but can be a promising addition. The plastisol coatings are further elaborated for various applications ranging from composite, via inks to flat coatings. During the last project years, the focus shifted mainly to application-oriented research. Demonstrators were developed for different markets, studies were made on which parameters they meet and where improvements are still required. The improved yarn level properties were further characterized for monofilament, multifilament and staple fiber. As a result, applications ranging from clothing to packaging to technical textiles come to the possibilities. For coating applications, plastisol inks are mainly considered because they can be processed with the current equipment. Because this application is very new, product-specific developments are currently being studied further at companies. Specific focus has also gone to foaming PLA. Foaming is a common technique for a variety of reasons, ranging from insulation, through price efficiency to lightweight applications. Many different methods of foaming are possible and the different methods (chemical, physical) have been optimized with and without the use of plasticizers. All research has shown that the choice of plasticizer has a very strong influence on the properties of the final product. An important factor here is biodegradability. PLA in itself is industrially biodegradable, meaning that it has a temperature of at least 60 ° C before it is degraded. Biodegradability could be accelerated through the use of specific plasticizers, which is important for many applications. The biggest disadvantage of plasticized PLA remains the limited choice of bio-based plasticizers. The usual choices are highly susceptible to migration, which of course hinders their applications. A number of plasticizers were identified during the project where little to no migration was observed. These plasticizers are of course an interesting choice and can also be used in blends to meet various requirements. One of the most important conclusions of the project is that the development of products based on PLA is very product-specific. The most important parameters that have an influence on the choice of PLA grade, plasticizer and processing process are therefore the desired strength, biodegradability and stability of the product. This weakness is immediately a strength because PLA lends itself to the manufacture of products that have to break down quickly in nature and at the same time it can also be used to manufacture products with a long service life."