Fundamental Measurements in Online Polymerization Reaction Monitoring and Control with a Focus on ACOMP

Polymer Colloids: Current Challenges, Emerging Applications, and New Developments

Polymer colloids are complex materials that have the potential to be used in a vast array of applications. One of the main reasons for their continued growth in commercial use is the water-based emulsion polymerization process through which they are generally synthesized. This technique is not only highly efficient from an industrial point of view but also extremely versatile and permits the large-scale production of colloidal particles with controllable properties. In this perspective, we seek to highlight the central challenges in the synthesis and use of polymer colloids, with respect to both existing and emerging applications. We first address the challenges in the current production and application of polymer colloids, with a particular focus on the transition toward sustainable feedstocks and reduced environmental impact in their primary commercial applications. Later, we highlight the features that allow novel polymer colloids to be designed and applied in emerging application areas. Finally, we present recent approaches that have used the unique colloidal nature in unconventional processing techniques.

Advances in continuous polymer analysis in flow with application towards biopolymers

Biopolymers, polymers derived from renewable biomass sources, have gained increasing attention in recent years due to their potential to replace traditional petroleum-based polymers in a range of applications. Among the many advantages of biopolymers can be included their biocompatibility, excellent mechanical properties, and availability from renewable feedstock. However, the development of biopolymers has been limited by a lack of understanding of their properties and processing behaviours. Continuous analysis techniques have the potential to hasten progress in this area by providing real-time insights into the properties and processing of biopolymers. Significant research in polymer chemistry has focused on petroleum-derived polymers and has thus provided a wealth of synthetic and analytical methodologies which may be applied to the biopolymer field. Of particular note is the application of flow technology in polymer science and its implications for accelerating progress towards more sustainable and environmentally friendly alternatives to traditional petroleum-based polymers. In this mini review we have outlined several of the most prominent use cases for biopolymers along with the current state-of-the art in continuous analysis of polymers in flow, including defining and differentiating atline, inline, online and offline analysis. We have found several examples for continuous flow analysis which have direct application to the biopolymer field, and we demonstrate an atline continuous polymer analysis method using size exclusion chromatography.

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Review of quantitative and qualitative methods for monitoring photopolymerization reactions

Authomatic in-situ monitoring and characterization of photopolymerization.

Polymer Molecular Weight Determination via Fluorescence Lifetime

Control of polymer molecular weight is critical for tailoring structure-function properties; however, traditional molecular weight characterization techniques have limited ability to determine the molecular weight of polymers in real time without sample removal from the reaction mixture, with spatial resolution, and of insoluble polymers. In this work, a fluorescence lifetime imaging microscopy (FLIM) method was developed that overcomes these limitations. The method is demonstrated with polynorbornene and polydicyclopentadiene, polymers derived from ruthenium-catalyzed ring-opening metathesis polymerization (ROMP). The polymer M_w, ranging from 35 to 570 kg/mol as determined by gel-permeation chromatography, was quantitatively correlated with the fluorescence lifetime. The revealed correlation then enabled time-resolved measurement of M_w during an ongoing ROMP reaction, requiring only 1 s per measurement (of a 45 μm × 45 μm polymer sample area), and provided spatial resolution, resulting in simultaneous characterization of polymer morphology. To provide the fluorescence signal, the initial reaction solutions contained a very low doping of a reactive norbornene monomer labeled with fluorescent boron dipyrromethene (BODIPY), such that 1 in every 10⁷ monomers contained a fluorophore. The resulting FLIM visualization method enables the rapid determination of the molecular weights of growing polymers without removal from the reaction mixture and regardless of polymer solubility.

Activation of homogenous polyolefin catalysis with a machine-assisted reactor laboratory-in-a-box (μAIR-LAB)

Catalysis discovery is typically limited to specialized labs – this work demonstrates an Artificially Intelligent Microreactor Lab in a Box applied to investigate the chemistry of different co-catalysts for zirconocene-catalyzed olefin polymerization.

Enabling technologies in polymer synthesis: accessing a new design space for advanced polymer materials

This review discusses how developments in laboratory technologies can push the boundaries of what is achievable using existing polymer synthesis techniques.

A review on modeling and control of olefin polymerization in fluidized-bed reactors

This is a detailed review on olefin polymerization models, and the most recent process control approaches used to control these nonlinear systems are presented. Great focus has been given to the various approaches of fluidized-bed reactor (FBR) modeling. Currently, there has yet to be a single model that blends these modeling aspects together into one single formulation. In this article, the classification of models works by looking at their assumption in considering the phases inside the system. Researchers have been unraveling vast information to narrate in detail the relations between various variables that can be found in FBRs. Although it is not difficult to understand about the basics of modeling polymer properties, a gap exists for future researchers to justify in detail the phenomena and reduce the gap between model predictions and the actual data. The various controlling approaches to control these FBRs have also been reviewed and categorized depending on the method they used to control significant parameters of this nonlinear system. The progress that can be expected in this field leads to the creation of more efficient reactors and minimizing waste.

Tracer microrheology study of a hydrophobically modified comblike associative polymer

The viscoelastic properties of associative polymers are important not only for their use as rheology modifiers but also to understand their complex structure in aqueous media. In this study, the dynamics of comblike hydrophobically modified alkali swellable associative (HASE) polymers are probed using diffusing wave spectroscopy (DWS) based tracer microrheology. DWS-based tracer microrheology accurately probes the dynamics of HASE polymers, and the extracted microrheological moduli versus frequency profile obtained from this technique closely matches that obtained from rotational rheometry measurements. Quantitatively, however, the moduli extracted from DWS-based tracer microrheology measurements are slightly higher than those obtained using rotational rheometry. The creep compliance, elastic modulus, and relaxation time concentration scaling behavior exhibits a power-law dependence. The length scale associated with the elastic to glassy behavior change is obtained from the time-dependent diffusion coefficient. The Zimm-Rouse type scaling is recovered at high frequencies but shows a concentration effect switching from Zimm to more Rouse-like behavior at higher concentrations.

Living Radical Polymerization by the RAFT Process – A Third Update

This paper provides a third update to the review of reversible deactivation radical polymerization (RDRP) achieved with thiocarbonylthio compounds (ZC(=S)SR) by a mechanism of reversible addition-fragmentation chain transfer (RAFT) that was published in June 2005 (Aust. J. Chem. 2005, 58, 379). The first update was published in November 2006 (Aust. J. Chem. 2006, 59, 669) and the second in December 2009 (Aust. J. Chem. 2009, 62, 1402). This review cites over 700 publications that appeared during the period mid 2009 to early 2012 covering various aspects of RAFT polymerization which include reagent synthesis and properties, kinetics and mechanism of polymerization, novel polymer syntheses, and a diverse range of applications. This period has witnessed further significant developments, particularly in the areas of novel RAFT agents, techniques for end-group transformation, the production of micro/nanoparticles and modified surfaces, and biopolymer conjugates both for therapeutic and diagnostic applications.