Dodecyl Methacrylate Research Articles

Dodecyl methacrylate (DM) dispersion-assisted surface modification approach for increasing crystallinity of coir fibers

Coir fiber crystallinity is crucial since it widens the range of possible uses for natural fiber. To increase the crystallinity of coir fiber, the study describes an easy-to-use, simple-to-implement method that is cost-effective, eco-friendly, and highly productive. With the help of dodecyl methacrylate disperson, hydrocarbon molecules of varying chain lengths are covalently attached to the surface of coir fibers, modulating their surface wettability. There are a few different long-chain hydrocarbon compounds employed, including n-butyl methacrylate, n-octyl acrylate, and dodecyl methacrylate (DM), but DM has shown to be the most effective. The degree of grafting yield alteration is determined gravimetrically. It has been found that grafting yields of 28–30 wt.% can be used to convert hydrophilic coir fibers into water repellent crystalline fibers (water contact angle 148°). A total of 15 nm of dispersion, a disperson rate of 2 nm/min, DM concentration of 20%, and water content of 10% are fixed as key reaction parameters. Thermal and mechanical analyses show no significant changes in the fiber structure during alteration. The grafting and changes in surface wettability are well supported by the surface morphology of pure and modified coir fiber, which can be seen using scanning electron microscopy.

Polymer-Coated Nanoparticles and Pickering Emulsions as Agents for Enhanced Oil Recovery: Basic Studies Using a Porous Medium Model

Globally the overall oil recovery factors for primary and secondary recovery range from 35% to 45%, and a tertiary recovery method that can enhance the recovery factor by 10–30% could contribute to the energy supply. The use of nanoparticles in enhanced oil recovery (EOR) processes comprises an emerging and well-promising approach. Polymer-coated nanoparticles (PNPs) were synthesized through the free radical polymerization (FRP) of the monomers 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPSA) and dodecyl methacrylate (DMA) on the surface of acrylic-modified spherical silica nanoparticles. The obtained PNPs were characterized using Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR) and thermogravimetric analysis (TGA). Dispersions of PNPs were prepared in salt (NaCl, CaCl2) aqueous solutions, the static oil/water interfacial tension were measured using the Du Nouy ring method, and changes caused based on the oil/water contact angle were recorded optically. The PNP dispersions were used to stabilize and characterize shear-thinning oil-in-water Pickering emulsions. The capacity of the PNP dispersions and Pickering emulsions to mobilize the trapped ganglia of viscous paraffin oil, which remained after successive tests of drainage and primary imbibition, was tested with visualization experiments of the secondary imbibition in a transparent glass-etched pore network. The synthesized SiO2-P(AMPSA-co-DMA) nanoparticles were stable even at high temperatures (~200–250 °C) and displayed excellent stability in aqueous dispersions at high ionic strengths with the presence of divalent cations, and their dispersions generated stable oil-in-water Pickering emulsions with a shear-thinning viscosity. The oil-recovery efficiency is maximized when the most viscous Pickering emulsion is selected, but if energy cost factors are also taken into account, then the less viscous Pickering emulsion is preferable.

Triple physical cross-linking cellulose nanofibers-based poly(ionic liquid) hydrogel as wearable multifunctional sensors

A novel triple physical cross-linking poly(ionic liquid) hydrogel, composed of poly(acrylamide-co-dodecyl methacrylate-co-1-vinyl-3-methyluracil-imidazolium chloride)/cellulose nanofibers-Ca2+ (PADV/CNFs-Ca2+), was synthesized through micellar-copolymerization followed by a solvent-soaked procedure. The synergistic interactions in polymer network (i.e. the hydrophobic association of dodecyl methacrylate moiety in surfactant micelles, the hydrogen bondings between imidazolium monomer segments and other monomer segments in polymers, and the ionic coordination between Ca2+ and -COO− on cellulose nanofibers surface) endowed the hydrogel with excellent mechanical properties, including high strength (754 kPa of tensile strength and 1905 kPa of compressive strength), outstanding stretchability (1963 %), elastic modulus (56.5 kPa) and remarkable mechanical durability (200 cycles with 500 % deformations and 100 cycles at 50 % compression strain). Besides, this hydrogel exhibited other advantages, such as satisfied conductivity (28.7 mS/cm), high strain/pressure/temperature-sensitive behavior, precise and stable signal transmission, varying degrees of antibacterial activity, and biocompatibility. Owing to the exceptional comprehensive performance, the hydrogel was then assembled as a multifunctional sensor to monitor the joint motion, vocal cord vibration, tactile sensation and body temperature with remarkable sensitivity in real time. This work offered a new strategy for the fabrication of durable, biocompatible, antibacterial and conductive materials for wearable multifunctional electronic devices.

Controlled synthesis and solution properties of copolymers of methacrylic esters and ammonium-containing methacrylamide

Copolymers based on oligo(ethylene glycol) methacrylate, dodecyl methacrylate, and the cationic monomer N-methacryloylaminopropyl-N,N-dimethyl-N-propylammonium bromide have been obtained by reversible addition−fragmentation chain-transfer polymerization in high yields and in a controlled mode. The influence of the composition of the obtained polymers on the solubility in water and organic solvents, distribution in the water-octanol system, and interfacial tension at the water-oil interface is shown. The presence of thermoresponsive properties for polymers in water was found, and their aggregation in aqueous media was also studied.

Anionic amphiphilic copolymers as potential agents for enhanced oil recovery

To develop “smart fluids” for enhanced oil recovery from reservoir rocks, comb-type amphiphilic copolymers were synthesized through free radical polymerization (FRP) of: (i) the hydrophilic, anionic monomer 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPSA) that offer a hydrophilic character to the final copolymers; (ii) the weakly acidic hydrophilic monomer acrylic acid (AA); (iii) the hydrophobic monomer dodecyl methacrylate (DMA). The polymers were characterized by Proton Nuclear Magnetic Resonance (1H NMR), Attenuated Total Reflection Fourier Transform Infrared Spectroscopy (ATR-FTIR), fluorescence probing, Dynamic Light Scattering (DLS) and electrophoresis. Stable polymer solutions were prepared without and with the presence of salts (NaCl, CaCl2, MgSO4). The dynamic air/water surface and oil/water interfacial tensions were measured by the pendant drop method, and their steady-state values were estimated with fitting to asymptotic relations predicting the long-time behavior. Moreover, the wettability of water/air and water/oil to glass or poly(methyl methacrylate) (PMMA) surface was quantified by measuring the contact angles. Oil-in-water Pickering emulsions were prepared by mixing n-dodecane with polymer solutions and their stability was evaluated macroscopically with optical inspection, and microscopically by measuring the oil drop size distribution and shear viscosity. Polymer solutions and Pickering emulsions were tested as agents for the displacement of the residual n-dodecane from a glass-etched pore network. The long-lasting retention of polymer solution in the pore network makes the solid surface more hydrophilic, facilitating the fission of oil ganglia into smaller ones which are mobilized easier, resulting in a final EOR efficiency between 10% and 18%. When using an emulsion as displacing fluid, the viscosity ratio and capillary number increase by orders of magnitude, the viscous forces prevail against the capillary ones, and the growth pattern becomes a frontal drive leading to a high EOR efficiency of ∼94%.

Electron beam assisted recycling of polyurethane (PU) sponge: Turning it into a superabsorbent for wastewater treatment

AbstractPolyurethane (PU) sponge is being used on a large scale now‐a‐days, but that generates environmental pollution as it is not bio‐degradable. Moreover, the PU recycling existing techniques face several problems, which are being addressed sincerely throughout the world. Here, we report an easy, scalable, environment‐friendly, economic, and high throughput technique for converting scrap PU sponge into a superabsorbent for wastewater treatment. This is a new strategy for recycling scrap PU foam. This conversion follows the modification of surface energy of the PU sponge and generation of tiny‐scale roughness by a single‐step electron beam (EB) radiation‐assisted covalent attachment of dodecyl methacrylate (DMA) onto the waste PU sponge. The effect of degree of modification on the surface wettability is studied. Important process parameters namely, total dose, DMA concentration, solvent composition, and so forth are systematically varied and optimized to achieve the required extent of modification (~30 wt%). This desired degree of modification is achieved at 30 kGy total dose and in 15 vol% DMA concentration and 15 vol% water content in the reaction mixture. Grafting yield is measured gravimetrically and successful grafting is further confirmed by Fourier‐transform infrared spectroscopy, surface wettability, and surface morphology. The recycled PU shows superhydrophobicity with very high water contact angle (152°). Now, the recycled sponge can remove major liquid components of wastewater, namely, toxic organic solvents, oily liquids, nonpolar solvent soluble dyes from water media with high absorption capacity (25–30 g/g) successfully.

Polymer-functionalized nanoparticles as agents for the in situ remediation of oil-contaminated soils

In-situ flushing of chemicals, such as nanoparticle (NP) suspensions, and NP-based Pickering emulsions, is a well-promising method for the remediation of soils and aquifers contaminated with non-aqueous phase liquids (NAPLs) and the enhanced oil recovery from reservoir rocks. Linear and comb-type copolymers were synthesized by combining (i) hydrophilic, anionic monomers like 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPSA) and acrylic acid (AA) with (ii) hydrophobic monomers like dodecyl methacrylate (DMA). Moreover, polymer-coated nanoparticles (PNPs) was prepared by post-grafting and surface initiated free radical polymerization (FRP) on commercial silica nanoparticles. Dilute dispersions of polymers and PNPs were mixed with salts (NaCl, CaCl2), their dynamic surface and oil/water interfacial tensions were measured by the pendant drop method, and the wettability of all fluid systems to glass surface was quantified by measuring the contact angle. Oil-in-water Pickering emulsions were prepared by dispersing n-dodecane in polymers and n-decane in PNP-colloid with ultrasound probe, and their stability was evaluated by tracking the phase separation and changes of rheological properties, as functions of time. Furthermore, the most stable polymers and PNP-based dispersions and emulsions were chosen and tested as chemicals for the removal of residual oil from a transparent glass-etched pore network.

Dodecyl Methacrylate Polymerization under Nanoconfinement: Reactivity and Resulting Properties

Dodecyl Methacrylate Polymerization under Nanoconfinement: Reactivity and Resulting Properties

Synthesis, characterization, and performance of alkyl methacrylates and tert-butylaminoethyl methacrylate tetra polymers as pour point depressants for diesel Influence of polymer composition and molecular weight

This paper presents the synthesis, characterization, and performance analysis of methacrylate-based polymer additives containing tert-butylaminoethyl methacrylate in their structure on the low-temperature properties of diesel fuel. The additives were synthesized by free radical polymerization and the composition was varied between different comonomers. The molecular weight of the additives was reduced using a chain transfer agent and determined by gel permeation chromatography (GPC). The crystallization behavior of the additives and formulated diesel was observed by differential scanning calorimetry (DSC) and optical microscopy with polarization. Standard tests according to EN 116 for the Cold Filter Plugging Point (CFPP), ASTM D5771 for the Cloud Point and ASTM D5950 for the Pour Point (PP) have shown a great improvement in low-temperature properties. The synthesized additive containing 35 mol% methyl methacrylate and a 3:1 M ratio of dodecyl and octadecyl methacrylate showed the best results, lowering the CFPP of diesel by up to 10 °C (-18 °C) and the PP value by up to 30 °C (-48 °C) compared to pure diesel. Microscopic images confirmed that the additive changed the morphology of the wax crystals from needle-like to spherical and that the composition affects the crystal morphology.

Synthesis and properties of surfactants for carbon nanotubes based on copolymers of 2-N-morpholinoethyl methacrylate with dodecyl methacrylate and styrene

The copolymerization reactivity ratios for 2-N-morpholinoethyl methacrylate (MEMA) with dodecyl methacrylate (DDMA) or styrene (ST) were estimated. The efficiency of the prepared polymers for dispersion of MWCNT in toluene was also studied. A wide range of copolymer compositions (all 10 mol% steps) were prepared using tert-butyl peroxy-2-ethylhexanoate (0.02 mol dm−3) as initiator isothermally (70 °C) to low conversions (< 10 wt%). In the case of DDMA/MEMA copolymerization, there is a slight tendency for both monomers to react more with MEMA. The reactivity ratios obtained are r(DDMA) = 0.86 and r(MEMA) = 1.05. The reactivity ratios for the copolymerization of ST/MEMA are both <1 and are r(ST) = 0.35 and r(MEMA) = 0.59, indicating a higher reactivity of each monomer with the other monomer. The addition of small amounts (10 mol%) of MEMA to DDMA homopolymer significantly increases its thermal stability (the temperature at 50 wt% loss is 46 °C higher). For ST/MEMA, the addition of MEMA gradually decreases the thermal stability (the temperature difference at 50 wt% loss between the homopolymers is 25 °C). The best dispersion of MWCNT in toluene is obtained with the ST/MEMA copolymer containing 42 mol% MEMA, as shown by UV–Vis measurements and visual inspections after the gravity test. The obtained results contribute to the further development of polymeric surfactants and stimuli-responsive polymers.

Application of hydrophobically modified hydroxyethyl cellulose-methyl methacrylate copolymer emulsion in paper protection

Abstract Paper cultural relics are important historical and cultural heritage. However, they are easy to be damaged with time. In order to improve the mechanical strength, water resistance and delay aging of paper, hydrophobically modified hydroxyethyl cellulose-methyl methacrylate copolymer emulsion for paper protection was synthesized, with hydroxyethyl cellulose as the matrix, methyl methacrylate, butyl acrylate glycidyl methacrylate, and dodecyl methacrylate as the graft polymers. The prepared emulsion was applied to paper protection. By testing the effects of emulsion with different mass concentrations on the tensile strength, folding endurance, tear strength, whiteness and gloss of paper, the suitable conditions for the application of paper protection were found. The results showed that the mechanical properties of the paper coated with 10 % emulsion were significantly improved, and the gloss and whiteness were basically unchanged. The appearance of the paper did not change obviously, which was in line with the principle of “repair as old, keep the original”. At the same time, the aging resistance and water resistance experiments show that paper coated with the new material has certain aging resistance and water resistance. Therefore, the prepared hydroxyethyl cellulose-methyl methacrylate copolymer emulsion has great application prospects in the protection of paper.

Impeding the Medical Protective Clothing Contamination by a Spray Coating of Trifunctional Polymers.

The risk of fomite-mediated transmission in the clinic is substantially increasing amid the recent COVID-19 pandemic as personal protective equipment (PPE) of hospital workers is easily contaminated by direct contact with infected patients. In this context, it is crucial to devise a means to reduce such transmission. Herein, we report an antimicrobial, antiviral, and antibiofouling trifunctional polymer that can be easily coated onto the surface of medical protective clothing to effectively prevent pathogen contamination on the PPE. The coating layer is formed on the surfaces of PPE by the simple spray coating of an aqueous solution of the trifunctional polymer, poly(dodecyl methacrylate (DMA)–poly(ethylene glycol) methacrylate (PEGMA)–quaternary ammonium (QA)). To establish an optimal ratio of antifouling and antimicrobial functional groups, we performed antifouling, antibacterial, and antiviral tests using four different ratios of the polymers. Antifouling and bactericidal results were assessed using Staphylococcus aureus, a typical pathogenic bacterium that induces an upper respiratory infection. Regardless of the molar ratio, polymer-coated PPE surfaces showed considerable antiadhesion (∼65–75%) and antibacterial (∼75–87%) efficacies soon after being in contact with pathogens and maintained their capability for at least 24 h, which is sufficient for disposable PPEs. Further antiviral tests using coronaviruses showed favorable results with PPE coated at two specific ratios (3.5:6:0.5 and 3.5:5.5:1) of poly(DMA-PEGMA-QA). Moreover, biocompatibility assessments using the two most effective polymer ratios showed no recognizable local or systemic inflammatory responses in mice, suggesting the potential of this polymer for immediate use in the field.

Porphyrin-cored amphiphilic star block copolymer photocatalysts: Hydrophobic-layer effects on photooxidation

Pd-contained porphyrin-cored (P(Pd)) amphiphilic star block copolymers with a hydrophobic interior, including either poly(methyl methacrylate) (PMMA) or poly(dodecyl methacrylate) (PDMA), and poly(ethylene glycol) methyl ether methacrylate (PEGMA) hydrophilic outer layer were synthesized by Ru-catalyzed atom transfer radical polymerization (ATRP). The acquired starpolymer photocatalysts were examined for photooxidation of furfural. The starpolymers with the PDMA hydrophobic interior led to higher efficiency in the photooxidation of furfural than the starpolymers without hydrophobic interior and with the PMMA interior. In addition, the grater hydrophobic PDMA fraction exhibited a higher photooxidation efficiency. Those experimentally demonstrated the importance of the hydrophobic interior toward efficient photooxidation. We believe that this study provides a fundamental idea in developing amphiphilic star block copolymer photocatalysts.

Comb-like poly(dodecyl methacrylate) modified SiO2 nanoparticles as nanohybrid coatings: Electron beam grafting and tuning superhydrophobic/water-repellent surface studies

The current research focuses on tailoring silica nanoparticles (SiO2NPs) with comb-like poly(dodecyl methacrylate) (PDMA) brushes and tuning coating parameters based on roller coating process for confining surface morphology towards hydrophobic and superhydrophobic including water-repellent surface. Electron beam (EB) induced a simultaneous “graft-from” polymerization of DMA monomer onto vinyl modified SiO2NPs (SiO2NPs-V) was established in an inventive castor oil/ethanol mixed solvent. Functional surface chemistry of SiO2NPs and nanorough surface topography controlled by NPs content and coating thickness mainly influences the hydrophobic/superhydrophobic, water-repellent, and water absorption properties including gloss values, whiteness and yellowness index of coated papers. The papers coated with SiO2NPs-V-PDMA/PVA of 6–10 wt% with the thickness of ~10–14 μm exhibited matt surface and provided superhydrophobic and water-repellent properties. The coated paper has a desirable and stable water contact angle of 152°, low droplet adhesion with lower dynamic tilting angle (<5°), and 5.3-folds reduced water absorption. Our investigation provides compelling evidence that the SiO2NPs-V-PDMA obtained from EB modification and the developed coating formula for roller-based coating process are realistic approaches for hydrophobic/superhydrophobic coatings and printing inks for paper-based industries.

Regularities of the radical copolymerization of dodecyl (meth) acrylate and a new cationic monomer N-(dibutylaminomethyl) methacrylamide

The regularities of radical copolymerization of dodecyl methacrylate (DMA) or dodecyl acrylate (DA) with a new cationic monomer - N-(dibutylaminomethyl) methacrylamide (DBAMMA) in toluene solutions were determined. The copolymers formed at low conversions in the DMA-DBAMMA system are enriched in ether units, and in the DA-DBAMMA system - in aminoamide units. The relative activities of comonomers determined by the Feineman-Ross and Kehlen-Tudosh methods in the first case were 1.56-1.60 (DMA) and 0.87-0.89 (DBAMMA), in the second case - 0.53-0.64 (DA) and 0.80-0.90 (DBAMMA).

Towards a Polymer-Brush-Based Friction Modifier for Oil

To meet the need for oil-compatible friction modifier additives that can significantly reduce energy consumption in the boundary-lubrication regime, a macromolecular design approach has been taken. The aim was to produce a lubricious polymer film on the sliding surfaces. A series of readily functionalizable block copolymers carrying an oleophilic poly(dodecyl methacrylate) block and a functionalizable poly(pentafluorophenyl methacrylate) block of various lengths was synthesized by means of reversible addition-fragmentation chain-transfer (RAFT) polymerization. The poly(pentafluorophenyl methacrylate) block was used to attach surface-active nitrocatechol anchoring groups to the polymer. The friction-reduction properties of these polymers were assessed with 0.5 wt% solutions in hexadecane by means of rolling-sliding macroscopic tribological tests. Block copolymers with roughly equal block lengths and moderate molecular weights were significantly more effective at friction reduction than all other architectures investigated. They also displayed lower friction coefficients than glycerol monooleate—a commercially used additive. The film-formation ability of these polymers was examined using a quartz-crystal microbalance with dissipation (QCM-D), by monitoring their adsorption onto an iron oxide-coated QCM crystal. The polymer with highest lubrication efficiency formed a thin film of ~ 17 nm thickness on the crystal, indicating the formation of a polymer brush. Interferometric rolling-sliding experiments with the same polymer showed a separating film thickness of ~ 20 nm, which is consistent with the QCM-D value, bearing in mind the compression of the adsorbed layers on the two sliding surfaces during tribological testing.Graphical

Solubilization of Paclitaxel by Self-Assembled Amphiphilic Phospholipid-Mimetic Polymers with Varied Hydrophobicity.

2-Methacryloyloxyethyl phosphorylcholine (MPC) polymers have been used as a coating agent on medical devices and as a carrier in drug delivery systems (DDSs). Paclitaxel (PTX) is a water-insoluble anticancer drug whose solubilizer is necessary for administration. Block and random copolymers composed of hydrophilic MPC and butyl methacrylate, named PMB, show different properties, depending on the polymer sequence and MPC content. In the present study, we used amphiphilic MPC polymers comprising hydrophobic dodecyl methacrylate (DMA). The self-assembling properties and PTX solubilization of random and block poly(MPC-co-DMA)s (rPMDs and bPMDs) with different compositions were examined and compared. rPMDs with high DMA content formed large and relatively loose self-assembled structures, which solubilized PTX. However, bPMDs formed small and compact self-assembled structures with poor PTX solubilization. PTX solubilized by PMB with small and loose self-assembled structures showed efficient drug action, similar to free PTX; however, rPMDs fell short of demonstrating PTX efficiency. Our results suggest that the self-assembling properties and the hydrophobicity of amphiphilic MPC polymers largely affect PTX solubilization as well as drug action, which is required to be controlled by the polymer sequence, as well as the structure and composition of the hydrophobic monomer for efficient DDS.

Investigations of Polymethacrylate Tribochemical Films Using X-Ray Spectroscopy and Optical Profilometry

This study investigates the elemental composition and surface morphology of solid tribochemical films formed on steel surfaces. The reversible addition-fragmentation chain transfer (RAFT) method was used to synthesize nine different metal-free polymers, which were blended into commercial base oils. The polymers were either homopolymers of dodecyl methacrylate and ethylhexyl methacrylate or were co-polymers of these monomers with six polar monomers. After tribological testing at 100 °C using the ball-on-flat geometry, the resulting tribochemical films were imaged using scanning electron microscopy (SEM) and optical microscopy. The resulting tribochemical films have thicknesses around 50–100 nm. Two of the films corresponding to small (P1—imidazole-containing copolymer) and large (P3—less polar homopolymer) wear were cross-sectioned using focused ion beam (FIB) and analyzed for elemental composition using energy-dispersive X-Ray (EDX) mapping. Oxygen and nitrogen enrichment was observed, consistent with the relative chemical composition of the precursor polymers. Transmission electron microscopy (TEM) evidence suggests that at the worn surface, some organic elements penetrate or are mixed into the steel substrate giving an interlocking appearance. The two samples examined with TEM showed that P1 tribofilm is diffused or mixed with the steel substrate more so than P3, suggesting a stronger affinity and contact during tribofilm formation.

The Effect of Hydroxyl on the Superhydrophobicity of Dodecyl Methacrylate (LMA) Coated Fabrics through Simple Dipping-Plasma Crosslinked Method

In order to obtain stable superhydrophobicity, suitable hydrophobic treatment agents should be selected according to different material properties. In this paper, cotton and poly(ethylene terephthalate) (PET) fabrics were respectively coated with dodecyl methacrylate (LMA) via argon combined capacitively coupled plasma (CCP), and the surface hydrophobicity and durability of the treated cotton and polyester fabrics are also discussed. An interesting phenomenon happened, whereby the LMA-coated cotton fabric (Cotton-g-LMA) had better water repelling and mechanical durability properties than LMA-coated PET fabric (PET-g-LMA), and LMA-coated hydroxyl-grafted PET fabrics (PET fabrics were successively coated with polyethylene glycol (PEG) and LMA, PET-g-PEG &amp; LMA) had a similar performance to cotton fabrics. The water contact angles of Cotton-g-LMA, PET-g-LMA and PET-g-PEG &amp; LMA were 156°, 153° and 155°, respectively, and after 45 washing cycles or 1000 rubbing cycles, the corresponding water contact angles decreased to 145°, 88°, 134° and 146°, 127° and 143°, respectively. Additionally, thermoplastic polyurethane (TPU) and polyamides-6 (PA6) fabrics all exhibited the same properties as the PET fabric. Therefore, the grafting of hydroxyl can improve the hydrophobic effect of LMA coating and the binding property between LMA and fabrics effectively, without changing the wearing comfort.

Thermokinetic parameter estimation of RAFT solution polymerization of dodecyl methacrylate by reaction calorimetry

The kinetics of RAFT polymerization of a dodecyl methacrylate controlled by a trithiocarbonate as a chain transfer agent (CTA) are studied by measuring the thermal profile in an RC1-RTCal reaction calorimeter. Contrary to classical methods such as electron spin resonance spectroscopy, the equilibrium constants related to the addition and fragmentation steps are estimated for a high degree of polymerization. The estimation method consists of a comparison between the measured thermal profiles and those built from models reflecting the instantaneous balances of mass and energy. The influence of the concentration of the transfer agent on the characteristics of the polymer (molar mass and dispersity) was also studied at different reaction temperatures. An increase in the concentration of CTA decreases the viscosity of the medium due to a more homogeneous distribution of the small sizes of the polymers. The influence of reaction temperature on the characteristics of polymers is reduced in the presence of CTA.