Low-phosphorus maleic acid and sodium ρ-styrenesulfonate copolymer as calcium carbonate scale inhibitor

Synthesis, characterization and properties of a novel environmentally friendly ternary hydrophilic copolymer

A novel environmentally friendly scale inhibitor was synthesized by the free radical polymerization of itaconic acid (IA), acrylamide (AM), and sodium p-styrene sulfonate (SSS). The structures of the copolymers were characterized using FTIR, UV, and ¹H-NMR, which proved successful in obtaining the expected target structures. The synthesis conditions such as monomer ratio, initiator dosage, titration time, and reaction temperature were optimized by the static scale inhibition method, and the expected polymeric scale inhibitor with a competent scale inhibition performance was obtained. The copolymer conversions at different temperatures were obtained indirectly by bromination titration, and the relationship between the molecular weight of the polymer and the scale inhibition performance at different reaction temperatures was also investigated by GPC. The results showed that the copolymer had a good ability to control calcium carbonate scaling, and the inhibition rate of CaCO₃ reached 84.7% at a dose of 30 mg L^-1. The microscopic morphology and structure of calcium scales were analyzed by SEM, FTIR, and XRD, and it was concluded that the copolymer could change the crystallization path of calcium carbonate from stable calcite to vaterite. That could be dispersed in water. The proposed inhibition mechanism suggests that surface complexation between polymer functional groups and Ca²⁺ leads to excellent solubility of the complexes. These findings suggest that the prepared green copolymers have great potential for oilfield applications.

Biodegradability as an Off-Ramp for the Circular Economy: Investigations into Biodegradable Polymers for Home and Personal Care

ConspectusConsumer pressure for globe-conscious products is pushing brand-owners big and small to provide transparency on the origin and fate of their ingredients. One such market where sustainable product growth has outpaced market growth is in home and personal care. Products in this space clean or care for our bodies, our homes, our environments, and the materials we encounter every day. Many of these materials are used and then washed down the drain, making the fate of these products a tangible end point for the consumer. Life cycle assessment (LCA) is a well-established methodology for determining potential environmental impacts of products and can be used to quantify the overall carbon footprint of the raw materials, the process to manufacture, and the transportation of the product around the globe. LCAs are calibrated to one metric, often kilograms of carbon dioxide (CO₂) equivalents, to capture the overall carbon footprint. One aspect notably absent from many LCAs is the end of life for the product. Interestingly, consumers are driving a push for biodegradable materials that would not persist in the environment, but as materials biodegrade, they release carbon dioxide to the atmosphere. This release of CO₂ places the benefits of biodegradation on the ultimate fate of raw materials in contradiction with carbon reduction methods such as carbon capture and carbon recycling that improve the LCA of a given product. In this Account, we describe the impact of biodegradation on the circular economy and discuss the development of natural, modified natural, and synthetic polymers to provide biodegradable alternatives to less degradable materials in the home and personal care markets. Building a chemical toolbox which can meet the functional and economical requirements of products on the market today while improving their sustainability profile is a huge challenge, which will not have a single answer. Among many current internal research initiatives, one vignette will be highlighted to showcase the research on a synthetic polymer with improved biodegradability for the dish care market. This novel polyelectrolyte, a copolymer of itaconic acid, acrylic acid, and vinyl acetate, was designed to break down into digestible daughter products in a wastewater treatment plant while demonstrating stability both on the shelf and in the dishwasher.

Probing the effects of polymers on the early stages of calcium carbonate formation by stoichiometric co-titration

Potentiometric titrations are a powerful tool to study the early stages of the precipitation of minerals such as calcium carbonate and were used among others for the discovery and characterisation of key precursors like prenucleation clusters. Here we present a modified procedure for conducting such titration experiments, in which the reactants (i.e. calcium and (bi)carbonate ions) are added simultaneously in stoichiometric amounts, while both the amount of free calcium and the optical transmission of the solution are monitored online. Complementarily, the species occurring at distinct stages of the crystallisation process were studied using cryogenic transmission electron microscopy. This novel routine was applied to investigate CaCO₃ nucleation in the absence and presence of polymeric additives with different chemical functionalities. The obtained results provide new insights into the critical steps underlying nucleation and subsequent ripening, such as the role of liquid mineral-rich phases and their transformation into solid particles. The studied polymers proved to interfere at multiple stages along the complex mineralisation pathway of calcium carbonate, with both the degree and mode of interaction depending on the chosen polymer chemistry. In this way, the methodology developed in this work allows the mechanisms of antiscalants - or crystallisation modifiers in general - to be elucidated at an advanced level of detail.

Synthesis and Application of CCQDs as a Novel Type of Environmentally Friendly Scale Inhibitor

Carbon quantum dots (CQDs) are promising nanomaterials since they have smaller particle size, excellent biocompatibility, and low toxicity. However, no  one has found their high-scale inhibition performance so far. In this article, a new kind of green scale inhibitor, carboxyl carbon quantum dots (CCQDs), was synthesized through a simple method of thermal decomposition of citric acid. The as-prepared CCQDs have excellent scale inhibition performance for CaSO₄ and BaSO₄. With a static test of scale inhibition at a temperature of 0-80 °C, the antiscaling efficiency can reach 100% with low additions of CCQDs.

Linear-dendritic block copolymers as a green scale inhibitor for calcium carbonate in cooling water systems

Water-soluble monomer APEG-PG-(OH)n were produced and the Structure of APEG-PG-(OH)5 were identified by ¹H-NMR. APEG-PG-(OH)n were copolymerized with maleic anhydride (MA) to synthesize no phosphate and nitrogen free calcium carbonate inhibitor MA/APEG-PG-(OH)n. The structure and thermal property of MA/APEG-PG-(OH)5 were characterized and measured by ¹H-NMR, GPC and TGA. The observation shows that the dosage and n value of MA/APEG-PG-(OH)n plays an important role on CaCO₃ inhibition. MA/APEG-PG-(OH)5 displays superior ability to inhibit the precipitation of calcium carbonate, with approximately 97% inhibition at a level of 8 mg/L. The effect on formation of CaCO₃ was investigated with combination of SEM and XRD analysis.

Scale inhibitors with a hyper-branched structure: preparation, characterization and scale inhibition mechanism

In order to improve the scale inhibition efficiency of existing scale inhibitors for industrial water and to reduce the phosphorus pollution of water bodies, a new type of scale inhibitor with a hyper-branched structure has been developed.

Double-Hydrophilic Block Copolymer as an Effective and Environmentally Friendly Inhibitor for Phosphate and Carbonate Scales in Cooling Water Systems

In this paper, a series of linear-dendritic block copolymers allyloxy poly(ethylene glycol) polyglycerol (APEG-PG-(OH)n) copolymer, was synthesized by anionic polymerization of glycerol using allyloxy poly(ethylene glycol) (APEG). The polymers were characterized by FT-IR and 1H NMR. The polymers were tested as novel environment-friendly inhibitors for industrial cooling water circulation. The performance of AA/APEG-PG-(OH)n on inhibition of calcium phosphate and calcium carbonate precipitation was studied by static scale inhibition tests. It was shown that AA/APEG-PG-(OH)n exhibited excellent ability to control inorganic minerals, with approximately 99 % calcium phosphate inhibition and 85 % calcium carbonate inhibition at levels of 4 and 10 mg/L AA/APEG-PG-(OH)n, respectively. The effect on formation of calcium phosphate and calcium carbonate was investigated with combination of scanning electronic microscopy (SEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD) analysis, respectively.