From the bouncy tires on your car to the protective coatings on your walls, latex is everywhere! But this versatile material is far more than just those familiar applications. Let’s dive into the fascinating world of latex, exploring its history, its surprising versatility, and the cutting-edge research shaping its future.
Beyond Rubber Trees: The Latex Revolution:
The word “latex” might conjure images of rubber trees, and for good reason. Natural latex, harvested from these trees, has a long and storied history. But today, the term “latex” encompasses a much broader range of materials—primarily synthetic latexes created through a process called emulsion polymerization. This revolutionary technique allows us to create a vast array of materials with tailored properties, far surpassing the capabilities of natural latex alone.
A Versatile Material, Endless Applications:
The applications of latex are seemingly endless. Its unique properties—ranging from elasticity and strength to water resistance and adhesion—make it a star performer in a wide range of industries:
- Synthetic Rubber: Tires, hoses, belts—latex is the backbone of many essential products.
- Synthetic Plastics & Resins: Providing flexibility, durability, and water resistance in countless applications.
- Coatings & Adhesives: Protecting surfaces and binding materials together.
- Textile Aids: Improving the feel, performance, and durability of fabrics.
- Oilfield & Water Treatment Aids: Playing a crucial role in various industrial processes.
Polyacrylate Latex: A Star Performer:
Among the many types of synthetic latex, polyacrylate latex stands out for its versatility and exceptional properties. Scientists are constantly pushing the boundaries of polyacrylate latex technology:
- Latex Modification: Fine-tuning its properties through innovative modifications to meet specific application needs.
- Bio-Based Monomers: Developing more sustainable and environmentally friendly versions using renewable resources.
- Dynamic Covalent Bonds: Creating latexes with unique self-healing and adaptable properties.
- Degradable Polyacrylate Latex: Designing latexes that break down naturally, minimizing environmental impact.
The Future is Liquid:
Despite significant advancements, the journey of latex innovation continues. Researchers are striving to create even more sophisticated models to predict the behavior of latex during emulsion polymerization, paving the way for even more precisely tailored materials. Addressing challenges like the environmental impact of raw materials and the need for biodegradable polymers remains a key focus. The future of latex is bright, promising a world of sustainable and innovative applications. So next time you encounter a product made with latex, remember the rich history, incredible versatility, and exciting future of this amazing material!
Latex originally referred to natural rubber, and later with the maturity of synthetic latex technology, it was gradually extended to refer to a class of polymer colloids dispersed in water. It is a broad concept and is generally used as a description of emulsion polymerization products and natural rubber products. The term “emulsion” is also commonly used in the industry to describe latex. The most common synthetic latex is made of vinyl monomers such as ethylene, vinyl acetate, vinyl chloride, etc., or conjugated olefin monomers such as acrylic derivatives, styrene, butadiene, acrylonitrile, etc. Some foreign literature will also refer to waterborne polyurethane as polyurethanelatex, but it is relatively rare overall. Other resins, such as epoxy resins, silicone resins, and other water-based dispersions, are rarely called latex. To avoid confusion, the latex discussed in this article generally refers to synthetic latex and natural rubber prepared by emulsion polymerization.
The synthesis technology and application of latex can be traced back to the early 20th century and developed rapidly during World War II. From 1940 to 1980, a large number of papers on the kinetics of emulsion polymerization were published, the most famous of which is the Smith-Edwart theory and model, but in practice, most emulsion polymerization systems are far more complex than the Smith-Edwart model. Prior to 2008, emulsion polymerization kinetic models were continuously reported and simulated using computers. However, most of the models are only applicable to the aggregation of specific monomers and specific surface activities, and are only applicable to homopolymerization systems, binary or at most ternary copolymerization systems. When hydrophilic monomers, especially water-soluble monomers, are introduced into the polymerization system, the oligomers generated by the polymerization of hydrophilic monomers will form very complex colloidal behavior, which will lead to significant changes in kinetics, and the experimental results will deviate greatly from the original kinetic model. In addition, a large number of other complex processes will occur in oligomers grown from hydrophilic monomers, such as changes in the adsorption equilibrium between them and surface activity, precipitation from water covering the surface of other particles, formation of water-soluble polymers, or polymerization-induced self-assembly and complex morphology, which seriously affect the viscosity of the system. Therefore, in the past studies on the polymerization kinetics of emulsions, few researchers would consider water-soluble monomers such as acrylic acid and hydroxyacrylate for mathematical model design. However, in practical application, it is often necessary to use a variety of monomer copolymerization, and contain water-soluble monomers such as acrylic acid and hydroxyacrylate to achieve satisfactory application results, and it is difficult to apply the model in the literature. In fact, emulsion polymerization is a complex system involving four phases of oil, water, solid, gas and more, and the flow field is constantly changing. So far, there has been no reliable universal kinetic model that can predict emulsion polymerization. After 2010, the traditional study of emulsion polymerization kinetics has become very rare, and it seems to have become a research field that has been shelved because it cannot be solved for the time being. However, around 2000, the practical technology of emulsion polymerization and the application of synthetic latex products have been quite mature, and the industry has always been in a state where practice is ahead of theory. At that time, synthetic latex has been widely used in synthetic rubber, synthetic plastics, resin impact modifiers, coatings, adhesives, textile auxiliaries, oilfield auxiliaries, water treatment auxiliaries and other fields.
1 Common polyacrylate latex modification types and preparation methods
In order to adapt to a variety of application scenarios, a variety of industrialized modification types or preparation methods of waterborne polyacrylate latex have been developed in the past 30 years, such as core-shell/multi-level structure latex, hydroxyl polyacrylate latex, fluorosilicone modified latex, nanoparticle/polymer latex composite system and hybrid system of acrylic resin and other resins, which are relatively mature in research.1.1 Core-shell/multi-level structure latex
The main purpose of core-shell/multi-level structure emulsion is to achieve the coating of inorganic nanoparticles, specific polymer phase separation structures, or to improve the film-forming effect of emulsions. The coating of nanoparticles is generally to improve the interface and dispersion between inorganic particles and polymers, and the common method is to modify the surface of nanoparticles with lipophilicity, and then use the fine emulsion method for in-situ polymerization coating or Pickering emulsion polymerization coating. Specific phase separation structures can achieve specific optical or mechanical properties. From a preparation point of view, it is necessary to consider the type of polymer and the degree of cross-linking of the core layer, as well as the type of monomer of the shell. In essence, the shell monomer is required to have poor swelling ability of the core layer polymer, which can usually be achieved by polymer species and cross-linked core layers. The particle fusion in the process of latex film-forming mostly depends on the mutual diffusion of polymer segments in latex particles, and the latex particle structure of hard-core soft shell can effectively improve the film-forming performance of latex.1.2 Hydroxyl polyacrylate latex
Waterborne hydroxy-containing polyacrylate secondary dispersions or hydroxy-containing polyacrylate latex (hereinafter referred to as “hydroxypropylene dispersions” and “hydroxy-acrylic latex”) are an important component of waterborne two-component polyurethane (2K-PU). In terms of polymer properties and preparation process, hydroxypropylene dispersion is easier to obtain smaller particle size, higher hydroxyl content and smaller relative molecular weight than hydroxypropylene latex, and generally has a better curing effect. However, hydroxypropylene latex is limited by the characteristics of emulsion polymerization kinetics (especially the difficulty of free radical abortion and homogeneous nucleation in latex), and it is difficult to prepare products with narrow distribution, low relative molecular weight and high hydroxyl content. In recent years, the market has gradually favored “low hydroxyl fast drying” and low-cost products, so hydroxypropylene latex with larger particle size, higher relative molecular weight and easy preparation still has certain advantages. How to avoid the instability of emulsion polymerization caused by the homogeneous nucleation of a large number of hydrophilic hydroxyl monomers in the formulation is a key problem in the preparation of hydroxypropylene latex. In addition, the core-shell structure design to enrich the hydroxyl monomer on the surface of the particles is a reliable method to increase the effective hydroxyl content of hydroxypropylene latex.1.3 Fluorosilicone modified latex
There are many reports of fluorosilicone-modified polymer latex at home and abroad, and most of them are aimed at achieving hydrophobic, anti-fouling, chemical resistance and improving adhesion. The raw materials used involve polysiloxane, silane (monomer), fluorine-containing monomer, fluorosilicon modified nanoparticles, etc. However, there are some synthesis problems or application pitfalls in the fluorosilicon-modified latex system: (1) the fluorosilicon monomer has poor swelling ability of polyacrylic acid latex during emulsion polymerization, which is easy to cover the surface polymerization of latex particles, and reduces the charge density/hydration barrier layer on the surface of latex particles, so as to form a gel during the polymerization process; (2) The presence of surfactants makes the effect of fluorosilicon compounds in reducing surface energy “twice the effort”; (3) The macromolecular fluorosilicon compound segments in the copolymer/grafted state could not effectively migrate to the surface, so the expected effect could not be achieved. The above problems should be considered in the preparation and application of fluorine-silicon modified latex.1.4 Nanoparticle/polymer latex composite system
The purpose of preparing nanoparticle/polymer latex composite systems is usually to strengthen the polymer, build the surface roughness, or obtain the functional properties of the nanoparticles. Among them, obtaining the functional properties of nanoparticles is the most important, and it is also one of the most widely studied branches of emulsion composite systems. For example,TiO2, ZnO and other particles with photocatalytic properties can be applied to self-cleaning and antibacterial coatings; Two-dimensional nanoparticles such as zirconium phosphate, boron nitride, Mxene and graphene oxide can be used as shielding fillers to improve the barrier properties of coatings. In addition, nanoparticles are used to obtain photothermal response, infrared reflection, superhydrophilic surfaces, and conductive functions. The wide variety and complete functions of nanoparticles make the field of nanoparticle/polymer latex composite systems very broad. However, how to improve the dispersion/arrangement of nanoparticles in latex systems and give full play to their functional properties has always been the focus of work in this field.1.5 Hybrid system of waterborne polyacrylic resin and other resins
The hybrid system of waterborne polyacrylic resin and other resins is commonly found in polyurethane resins, epoxy resins, alkyd resins, amino resins and tackifying resins, including grafting, interpenetrating network construction and physical blending. In industrial applications, since polyacrylates and these resins can be chemically crosslinked during the drying process, direct blending can also achieve good compatibility and application results in most paint baking scenarios, so physical blending is generally used as the main means. Similarly, the preparation of hybrid resin systems is quite rich in types and means, and the unique properties of hybrid resins can be obtained as long as the dispersion and compatibility are solved.
2 Recent research progress in polyacrylate latex
The above introduces several aspects of the popular research of polyacrylate latex system in the past 30 years, and the research of these types of latex has entered a relatively mature stage, and all of them have been widely used in industry. The following types of polyacrylate latex are in the stage of hot research, and there is a trend of preliminary industrialization attempts or gradual expansion of industrialization. These types of polyacrylate latex include: latex prepared by controllable/active radical polymerization, latex containing bio-based monomers, latex containing dynamic covalent bonds, and backbone degradable polyacrylate latex.2.1 Polymerization of controllable/active radical emulsions
Controlled/reactive radical polymerization has developed rapidly in the past 20 years. Common examples include nitrogen oxide radical (mediated) polymerization (NMP), atom transfer radical polymerization (ATRP), and reversible addition-chain transfer (RAFT) radical polymerization. However, there are many subtle differences, such as the limited type of monomer applicable to NMP, the metal salts and ligands of ATRP are affected by the oil-water partition ratio, and the polymerization kinetics of RAFT is significantly affected by the relative molecular weight. These characteristics become more complex in the ionic-rich, multi-phase, and isolated systems of emulsion polymerization, and a series of reviews by Professor Zetterlund describe the properties of active radical polymerization in emulsion polymerization and dispersion polymerization systems. RAFT polymerization has the characteristics of wide monomer applicability and low influence of water and ions, so it is convenient to directly apply most traditional systems in emulsion polymerization (especially semi-continuous production processes). Therefore, among the three types of methods, the research on latex prepared by RAFT polymerization is the most common and the closest to the production application, and the following is an introduction to the application of polyacrylate copolymers prepared by RAFT emulsion polymerization.
Structurally structured amphiphilic polymers: Due to the flexible design of the RAFT reagent, the long-chain alkane hydrophobic segments can be designed on the RAFT reagent and then copolymerized with the hydrophilic monomer to obtain the amphiphilic structure. or introduce hydrophilic segments (polyoxyethylene segments) or groups (carboxylates, sulfonates or ammonium salts) into the RAFT reagent in advance, and then copolymerize with hydrophobic monomers; Or directly and successively carry out the dropwise addition of hydrophilic/hydrophobic monomers to prepare block copolymers to obtain amphiphilia. Such methods can easily enable the polymerization of soap-free emulsions, or the preparation of highly efficient wetting and leveling agents. Professor Ma Jianzhong’s review work has a detailed summary of this.
Polymerization-induced self-assembly: On the basis of the preparation of amphiphilic polymers by RAFT radical polymerization, the hydrophilicity of the polymer chain gradually deteriorates during the process of chain growth by appropriately adjusting the length of hydrophilic chain segments and the type of hydrophobic monomers, so that nanoparticles are precipitated into nanoparticles of various morphologies in water, and this process of forming nanoparticles is called polymerization-induced self-assembly (PISA). The morphology of nanoparticles generated by PISA is diverse, the most common are spherical, worm-like and vesicles, as well as rod-shaped, lamellar and jellyfish-like, etc., and the morphology can usually be regulated by the structure of the polymer (monomer type, relative molecular weight, etc.), the polarity of the dispersion medium and external stimuli (pH, temperature, microwave, etc.). At present, the most promising application of PISA-structured nanoparticles is in the biomedical field, such as the viscosity of the colloidal system will increase sharply in the process of spherical to worm-like transformation, which can be applied to gel embolic agents; The formation and destruction of hollow vesicle structures can realize drug embedding and delivery; The embedding of biological enzymes within the vesicle structure and the specific permeability of the vesicles can form a microreactor.
Phase separation block copolymers: RAFT polymerization is very convenient for the construction of regular block polymers, when the polymers in different segment regions are incompatible (e.g., polystyrene-butyl polyacrylate-polystyrene), such polymers themselves will undergo phase separation, depending on the monomer type, block sequence, and heat treatment conditions. Block polyacrylate polymers with phase-separated structures have the mechanical properties of strength, high resilience and low stress relaxation, and can also be used to prepare optical materials.2.2 Contains bio-based monomer latex
With the increasing awareness of sustainable development and environmental protection in the industry and the public, the search for bio-based raw materials independent of petrochemical sources to prepare synthetic polymer latex has become a hot topic in polymer synthesis research in recent years. The research on this topic is generally the use of compounds extracted from plants and by-products from industrial processing processes of related plant-based materials as part or all of the monomers (or raw materials) of polymer synthesis. For polymer latex, it seems to be back to the starting point of the original natural rubber, but in fact, the bio-based derivatives that can be used in polymer latex are quite abundant, and compounds such as alkenes, esters, acids, phenols and alcohols extracted from various plants can be derivatized and then become monomers suitable for emulsion polymerization. Different bio-based derivatives can introduce a variety of different groups to prepare polymer latex with different properties, which is far richer than natural latex collected directly from rubber trees.
At present, there have been many reports of bio-based raw materials directly related to polymer latex. The Sylvain Caillol group of the Charles Gerhardt Institute in France has done a lot of research in this field, they prepared the corresponding methacrylate monomers with three eugenol isomers and derivatives, and synthesized their homopolymerized latex, and compared the polymerization effects of different derivatized functional groups and different initiators (to investigate the conversion rate, latex stability, gel rate, etc.). The study concluded that ethoxy-derived dihydroeugenol corresponds to methacrylates with better polymerization and can be copolymerized with butyl acrylates to form stable latex. In one of their follow-up work, the acrylate prepared by ethoxy-derived dihydroeugenol was further studied, and at the same time, it was combined with Chuangyu lignanol and soybean oil to prepare latex and used as a coating resin, but the performance of the prepared resin was average, the tensile strength was only 0.25~1.25MPa, and the hardness of the pendulum was only 5~35s.
Another common bio-based raw material is cardanol, which is also derived from acrylates and subsequently used in emulsion polymerization to prepare latex. In addition to the two types of raw materials mentioned above, there are also polymer latex prepared from ferulicacid, myrcene, oleic acid, and galactoglucomannan as raw materials. Since acrylate-derived methods are the most versatile and mature, these bio-based raw materials are generally prepared as vinyl monomers for polymerization in the form of acrylate-derivative. However, most of the bio-based polymer latex reported in the literature cannot achieve the effect of conventional copolyacrylate latex in terms of conversion rate and performance. It is conceivable that any bio-based alkene, ester, acid, phenol and alcohol compound can be derived into acrylate monomers in one or two steps without any difficulty in terms of chemical viability, with the focus on improving their synthesis efficiency, the performance of polymer generation and the commercial viability of bio-based feedstock sources.
Research on bio-based monomers is not limited to the paper reporting stage, in fact, there are commercial products at this stage. (Isobornyl methacrylate) is a relatively special acrylic monomer that was commercialized earlier and is now available at allnex to provide isobornyl methacrylate from a bio-based source. Companies such as Procter & Gamble (P&G), BASF, Archer Daniels Midland (ADM) and Arkema (Arkema) have patents for the fermentation of bio-derived (metha)acrylic acid (esters), and the raw materials used for fermentation and production of (methacrylic acid) include lactic acid, acetic acid, methanol, ethanol, propylene glycol and glycerol, etc., which have been applied for patents and laid out intellectual property rights between 2008 and 2019. Polyacrylic acid emulsions prepared from bio-based raw materials have been sold as commercial products by Dow, Wanhua and allnex.
The preparation of polymers from bio-based raw materials is more concerned with the concept of sustainable development than the concept of environmental protection. At present, the emissions of many bio-based raw materials in the actual extraction and derivation process are sometimes greater than those of similar products produced by traditional refining and chemical production. In addition, bio-based raw materials cannot endow polymers with degradable properties, and most of the bio-based compounds after derivatization can no longer enter the microbial metabolism cycle, while the degradation of polymers essentially depends on the interruption of chemical bonds, and it is still necessary to introduce chemical structures that can be destroyed by organisms, environments or artificial production environments to achieve the degradable properties of polymers.2.3 Polymeric latex with dynamic covalent bonds
Dynamic bonds, as the name suggests, are chemical bonds that have their own equilibrium reactions and can undergo equilibrium movement or rate change under different conditions. In recent years, dynamic chemical bonds have been widely introduced into the design of polymers, which has greatly enriched the synthesis, properties and applications of polymer materials. The dynamic bonds in polymers can undergo active exchange reactions or equilibrium bond formation and bond breaking under specific conditions (e.g., temperature, pH), which directly leads to significant changes in the chemical structure and motion laws of polymer chains. This chemical change and change in chain segment dynamics enables the preparation of various functional materials such as self-healing polymer materials, shape memory materials, reprocessable cross-linked polymers, and controllable degradable materials.
Although there are many studies on polymers containing dynamic covalent bonds, there are few reports directly applied to the design of polymer latex, and these reports are all recent years (2020-2023). Gao et al. prepared a polyacrylate latex containing small molecules of furan methanol and bismaleimide, because furanmethanol and bismaleimide were dissolved by solvent and added to the latex system, without the need for free radical copolymerization of acrylates, the Diels-Alder reaction would not be destroyed by free radicals, and the introduction of dynamic covalent bonds could be realized. Based on this system, they have also developed this latex into a self-healing leather finish. Ahmed et al. prepared a waterborne polyurethane-polyacrylate latex containing sterically hindered urea structure, which can unravel sterically hindered urea bonds at 120°C and promote the repair of the polymer. Tajbakhsh et al. used a fine emulsion polymerization method to copolymerize borate ester double-bonded monomers and acrylic monomers into latex, which could increase the addition amount of double-bonded monomers containing dynamic covalent bonds to a high level (molar fraction 15%), and the polymer still had good performance of repeated processing at high cross-linking levels.
These works mainly discuss the widely known properties of self-healing/reprocessable cross-linked polymers, which are optimized for latex systems in specific aspects, but lack the further exploration of the specificity of dynamic covalent bonding in latex systems and the analysis of intrinsic details or kinetic parameters. The coalescence of latex particles into a film is actually equivalent to the interfacial self-healing properties at the microscopic level. On the basis of this viewpoint, Prof. Xinya Zhang’s research group used an efficient vibrationally resolved fluorescent probe as a tool to study the polymer diffusion kinetics in non-crosslinked, permanently cross-linked and dynamic disulfide bond cross-linked emulsion films, and concluded that dynamic disulfide bonds can promote polymer diffusion between cross-linked latex particles and improve latex film formation when activated.2.4 The main chain is degradable polyacrylate latex
The degradability and durability of polymers are often in a contradictory and balanced relationship, which needs to be selected in different applications. For example, for disposable products and consumables, it is more desirable that they degrade quickly after achieving their functions; For new energy battery adhesives, architectural coatings, adhesives and other application fields, it is hoped that they are durable and reliable. Many bio-based polymer designs also tend to introduce dynamic covalent bonds, which impart controllable chemical degradation properties to polymer resins.
In recent years, the risk assessment of micro-nano plastic particles on the marine environment and human health has been increasingly emphasized. Degradation properties are important and even necessary for polymer latex and their applications. Specifically, polymer latex is widely used in the civilian field, and there are a large number of untrained construction personnel in the application scenario, and even self-coating. In such cases, it is inevitable that polymer latex will be discharged fugitively in the form of waste liquid, and polymer latex itself is a micro-nano plastic particle, which poses an environmental risk. In addition, polymer latex is also widely used in adhesives, inks and coatings for consumables such as disposable products and printed products, and a large number of consumables are discarded, causing immeasurable microplastic pollution.
Polyester materials are currently the first choice for degradable polymers, but most polymer latex is derived from vinyl polymers, and because the synthesis of polyester is not suitable for emulsion polymerization, degradable polymer latex is not common in the early years. In addition, the backbone of vinyl polymers is carbon-carbon backbone, which is not sensitive to most degradation factors such as biological enzymes and environmental hydrolysis. Recently, the technology of ring-opening radical polymerization has been paid attention to, and it has been used for copolymerization with vinyl monomers to prepare carbon chain backbone polymers containing fragile chemical bonds such as ester bonds and thioester bonds on the carbon chain backbone. The nature of these fragile bonds is actually dynamic bonds, which enable rapid breakage under certain conditions, resulting in efficient degradation of polymers.
The most widely studied ring-opening radical comonomers are cyclicketeneacetals (CKAs) and thionolactones. The research history of cyclic acetal is relatively long, but it has recently been re-emphasized; Thiolactones are a relatively new class of ring-opening radical polymeric monomers. They are all capable of ring-opening polymerization by free radical attack and can undergo free radical copolymerization with vinyl monomers such as vinyl acetate, styrene, and acrylates. Homopolymerization occurs during the radical polymerization of enketone cycloacetals, and there is also competition between ring-opening polymerization and ring-retaining polymerization, and only the polymerization in the ring-open form can introduce ester bonds into the polymer backbone to achieve hydrolysis of the backbone. CKAs with different structures will have different ring-opening tendencies, and some KKAs can achieve 100% ring-opening polymerization. Among them, the most studied and mature CKA is 2-methylene-1,3-dioxepane (MDO), which is relatively simple to synthesize and has a good copolymerization effect with unconjugated vinyl monomers such as vinyl acetate. Dow Chemical Co., Ltd. uses MDO, an enone cycloacetal, to copolymerize with vinyl acetate to prepare latex for waterproof coating of disposable paper products. The latex has mild water and oil repellency after film formation, and is expected to be used for the surface coating of disposable paper tableware, and at the same time, it can achieve rapid degradation under alkaline conditions. The MDO monomer for this work was supplied by Wacker Chemie and Kuraray’s patent for MDO production can also be found, so the industrial production of MDO has already begun.
Thiolactones, on the other hand, do not self-polymerize and do not produce free radical polymerization that retains rings, which can effectively introduce thioester bonds into polymers, and their hydrolysis conditions are milder than ester bonds, and they are sensitive to the redox environment, which can achieve redox degradation. A typical and most widely studied thiolide, dibenzo[c,e]oxepane-5-thione (DOT), which breaks from the thioester bond when it opens the ring, and maintains the activity of free radicals to participate in copolymerization, and when copolymerized with styrene, it can prepare polystyrene with a broken backbone. Lansalot and D’Agosto’s research group reported that DOT was copolymerized with styrene and butyl acrylate to prepare latex, and the synthesized latex had good appearance and particle morphology. However, the introduction of DOT will reduce the reaction rate and the conversion rate of other monomers, and the resulting polymer emulsion can be efficiently degraded in an alkaline solution of 1,5,7-triazabicyclo[4.4.0]decyl−5-ene (TBD), and the relative molecular weight is reduced to 10%. In addition, the application of cyclic acetal and thiolactone has also been tried in the field of polymerization-induced self-assembly.
3 Conclusion
As the largest branch of water-based resin, polyacrylate latex has sustained and vigorous vitality in theoretical research and engineering applications. At present, the basic theory of emulsion polymerization has a guiding and explanatory role, but it cannot fully predict the results of industrial production. The emulsion preparation method has shown the role of inspiring and leading the development of downstream applications, but it involves many interdisciplinary fields, which require careful analysis and screening by practitioners based on their own experience.
For core-shell/multi-level structure latex, hydroxyl polyacrylate latex, fluorosilicone-modified polymer latex, nanoparticle/polymer latex composite system and hybrid system of acrylic resin and other resins have been developed for many years, practitioners can compare the successful commercial products and combine their own experience to screen out more reasonable and correct information from a variety of literature reports.
For the latest technological advances such as latex prepared by controllable/active radical polymerization, latex containing bio-based monomers, and degradable polyacrylate latex containing dynamic covalent bonds and backbones, there are few products that have been successfully commercialized, and most of them are still trying to commercialize or are still some distance away from industrial production.