Monomer Reactivity Ratios Research Articles

Radical Polymerization and Kinetics of N,N-diallyl-N,N-dimethylammonium Chloride and Vinyl Ether of Monoethanolamine

N,N-diallyl-N,N-dimethylammonium chloride (DADMAC) and vinyl ether of monoethanolamine copolymer (VEMEA) was synthesized by radical polymerization in aqueous media using ammonium persulfate as initiator. Copolymers synthesis was carried out by varying monomer composition at low conversion level. The viscosity of high molecular weight products was measured in aqueous 1 M NaCl solution and it was increased with increasing DADMAC amounts in the copolymer due to increasing positive charge. The structure of the product was identified by FTIR, 1H, 13C-NMR spectroscopies and conductometric titration methods. We calculated monomer reactivity ratios with help of Finemann-Ross, Kelen-Tudos, and inverted Finemann-Ross methods. It was found that DADMAC is more reactive than VEMEA, therefore the amount of DADMAC in the copolymers always dominated regardless of the initial monomer ratio in solution and it was shown that the monomers are connected randomly in the polymer chain. The effect of various parameters such as monomer [M], initiator [I] concentrations, ratio of comonomers, etc. on polymerization was investigated systematically. So, the polymerization rate (Rp) equation was found to be Rp=k[M]2.6[I]0.6 where molar fractions of DADMAC and VEMEA was 90:10 and the temperature was 65 °C. Degree of polymerization was examined by using various monomers and initiator concentrations via the dilatometeric method. It was found that the polymerization rate increased directly with total monomer concentration and initiator content.

Fluorescent core-shell polymer particles containing luminophore dyes: synthesis and optical response to acetone

Monodisperse dye-containing crosslinked particles are promising for application in novel optical chemical sensors due to their intrinsic sensitivity. However, preparation of these particles in aqueous media still remains a challenge, since luminophores inhibit radical processes or else cannot embed into polymer chains because of difference in monomer reactivity ratios. In this work, novel dye-containing monodisperse crosslinked particles were prepared and characterized. In order to obtain dye-containing monodisperse crosslinked particles, we studied seed copolymerization of styrene in the presence of divinylbenzene. The influence of nature and concentration of the used comonomers and co-solvents on shape, size distributions and surface characteristics of the particles formed was investigated. Shapes and diameters of the particles were analyzed by DLS, TEM and SEM. The data of SEM and optical spectroscopy studies demonstrated that the synthesized particles were able to self-assemble into thin-film three-dimensional ordered structures. Finally, the structures under study are promising for development of sensor devices with optical response to acetone.

Synthesis and characterization of poly(ethylene glycol) acrylate (PEGA) copolymers for application as polymeric phase change materials (PCMs)

In this study, we have reported the synthesis of copolymers of poly(ethylene glycol) acrylate (PEGA) with methyl methacrylate (MMA) in various ratios which can be utilized as polymeric phase change materials (PCMs). The monomer reactivity ratio of PEGA copolymers was determined by Fineman-Ross method. The values of r1 (PEGA) and r2 (MMA) were found to be 0.8164 and 0.3371 respectively. The thermal analysis performed by DSC indicated high fusion enthalpy of 168 J·g−1 at 55 °C for the feed ratio of 40:60 of PEGA:MMA (Copolymer mole fraction of 76:24). The crystallization behaviour shows the presence of spherulites but of smaller size compared to PEG and with reduced crystallization ability. The results point out the capabilities of PEGA to function as an effective PCM which can be utilized for numerous thermal energy storage applications.

A Methylene-bridged salicylaldiminato tridentate [ONS] binuclear titanium complex for ethylene-norbornene copolymerization

ABSTRACTA binuclear titanium complex Ti2La with methylene-bridged salicylaldiminato tridentate [ONS] ligand bearing octylthio sidearm was synthesized and used for the copolymerization of ethylene and norbornene (E-NB). The complex exhibited activity over 106 g/mol(Ti).h.atm and high degree incorporation of co-monomer (up to 49.9 mol %), affording high-molecular-weight copolymers with narrow molecular weight distribution. The E-NB copolymers produced by Ti2La/MMAO contained NN dyad and NNN triad sequences even at low norbornene feeds, in contrast to the observation of such sequences only at high level of NB incorporation for most other catalyst systems. The monomer reactivity ratios were calculated to be rE = 14.62 and rN = 0.08, of which the rN value was much larger than that from non-metallocene titanium catalyst systems. The catalytic performances of the binuclear complex Ti2La and its mononuclear analogue TiLb were also compared, with the binuclear complex exhibiting higher catalytic activity and NB incorporation ratio due to the binuclear cooperative effect, and producing much higher molecular weight copolymer due to the increased steric hindrance caused by close proximity of two growing chains. To the best of our knowledge, this is one of the few examples of binuclear catalyst for E-NB copolymerization with high activity and efficient incorporation of norbornene.

Synthesis of imide‐based methacrylic monomers and their copolymerization with methyl methacrylate: monomer reactivity ratios and heat resistance properties

ABSTRACTThe newly designed methacrylic monomer series 4‐phthalimidocyclohexyl methacrylate (PCMA), 4‐hexahydrophthalimidocyclohexyl methacrylate (HPCMA) and 4‐hexahydro‐3,6‐methanophthalimidocyclohexyl methacrylate (HMPCMA) were synthesized. Their homopolymers and methyl methacrylate (MMA) based copolymer series were polymerized by free‐radical polymerization. The copolymer compositions were characterized using 1H NMR spectra. The monomer reactivity ratios were calculated employing the Fineman−Ross (F‐T) and Kelen−Tüdös (K‐T) methods at low conversion. The values of r1 and r2 obtained by the F‐T and K‐T methods appear to be in close agreement (their average values are r1 = 1.3061 and r2 = 0.7336 for poly(PCMA‐co‐MMA), r1 = 1.5169 and r2 = 0.6840 for poly(HPCMA‐co‐MMA), r1 = 1.7748 and r2 = 0.5664 for poly(HMPCMA‐co‐MMA)) . The thermal stabilities and thermomechanical characteristics of the homopolymer and copolymer series were investigated by differential scanning calorimetry, thermogravimetric analysis and dynamic mechanical thermal analysis. © 2018 Society of Chemical Industry

Enantiomer-selective Living Polymerization of rac-Phenyl Isocyanide Using Chiral Palladium Catalyst

We report the polymerization of phenyl isocyanides with the chiral palladium(II) initiating system. The resulting polymers with optically active properties were obtained by polymerization of the racemic isocyanide monomer (rac-1), and enantiomerically unbalanced polymerization of the monomer was found, providing substantial evidence for the enantiomer-selective polymerization of rac-1 mediated through chiral catalyst. A comparison between the enantiomerically pure monomers, 4-isocyanobenzoyl-L-alanine decyl ester (1s) and 4-isocyanobenzoyl-D-alanine decyl ester (1r), revealed a drastic discrepancy in the reactivity ratio of their homopolymerizations. It turned out that the monomer reactivity ratio of 1s was higher than that of 1r with chiral ligands. The results clearly demonstrated the inclination for incorporation of the 1s enantiomer during the polymerization process and thus resulted in the enantiomer-selective polymerization in this system. The effects of the catalyst chirality on the optically active properties of polymerization were investigated, and it was concluded that the formation of higher-ordered conformation with a handed helicity might be attributed to the chiral induction of chiral palladium(II) catalyst. Moreover, the polymers obtained through the enantiomer-selective polymerization of the enantiomerically pure monomer were with a significant improvement of the optical activity if the chirality of the monomer and the catalyst matched with each other.

Accurate density functional theory (DFT) protocol for screening and designing chain transfer and branching agents for LDPE systems

This work emphasizes the importance of considering multiple reaction pathways when estimating the rate parameters for free radical polymerization using DFT.

Self-polymerization and co-polymerization kinetics of gadolinium methacrylate

Gadolinium methacrylate (Gd(MAA)3) was synthesized by using gadolinium oxide and methacrylic acid as the starting materials and its self-polymerization kinetic was studied based on non-isothermal and isothermal analysis. Moreover, the monomer reactivity ratios of methyl methacrylate (MMA) and Gd(MAA)3 were evaluated by using Kelen-Tüdõs method. The thermal neutron shielding properties of PMMA and poly(MMA-co-Gd(MAA)3) were calculated by MCNP program. The results show that the self-polymerization of Gd(MAA)3 can be initiated by thermal and free radical and its activation energy is 103.35 kJ/mol or 58.55 kJ/mol correspondingly in the solid state or aqueous solution. The polymerization rate, Rp, under low conversion at 65 °C is expressed as Rp = K[M]1.05[I]0.60. The reactivity ratios of r1 (MMA) and r2 (Gd(MAA)3) are 0.225 and 1.340, respectively. The ability of thermal neutron shielding of poly(MMA-co-Gd(MAA)3) is increased by gadolinium contents and is far better than PMMA.

Copolymerization of benzyl methacrylate and a methacrylate bearing benzophenoxy and hydroxyl side groups: Monomer reactivity ratios, thermal studies and dielectric measurements

Statistical copolymers of 2-hydroxy-3-benzophenoxy propyl methacrylate (HBPPMA) and benzyl methacrylate (BzMA) in different feed ratios were synthesized by free radical copolymerization method at 60 °C in presence of AIBN initiator. The compositions of copolymer were estimated from 1H-NMR technique. The monomer reactivity ratios of HBPPMA and BzMA were calculated as r1 (rHBPPMA)=0.51±0.076 and r2 (rBzMA)=1.07±0.140 for Kelen-Tudos method, and was estimated as r1=0.37±0.0006 and r2=0.64±0.0485 according to Fineman Ross equation. The average values estimated from the two methods showed that monomer reactivity ratio of benzyl methacrylate was a slightly high in comparison to HBPPMA. The copolymer system showed an azeotropic point, which is equal to M BzMA =m BzMA =0.43. DSC measurements showed that the Tg’s of poly(HBPPMA) and poly(BzMA) were 84 °C and 73 °C, respectively. The Tg in the copolymer system decreased with increase in benzyl methacrylate content. The decomposition temperature of poly(BzMA) and poly(HBPPMA) occurs in a single stage at about 207 °C and 260 °C, respectively. Those of HBPPMA-BzMA copolymer systems are between decomposition temperatures of two homopolymers. The dielectric constant, dielectric loss factor and electrical conductivity were investigated depend on the frequency of the copolymers. The highest dielectric constants depending on all the studied frequencies were recorded for the poly(HBPPMA) and the copolymer containing the highest HBPPMA unit. The dielectric constant for P(HBPPMA) and P(BzMA) at 1 kHz are 6.56 and 3.22, respectively. Also, those of copolymer systems were estimated between these two values. Similarly, poly(HBPPMA) and copolymers, which are prepared under the same conditions show the dissipation factor and conductivity as well.

How penultimate monomer unit effects and initiator influence ICAR ATRP of n‐butyl acrylate and methyl methacrylate

The relevance of penultimate monomer unit (PMU) effects and the selection of the correct initiator species under typical reversible deactivation radical copolymerization conditions is illustrated, using matrix‐based kinetic Monte Carlo simulations allowing the visualization of all monomer sequences along individual chains. Initiators for continuous activator regeneration atom transfer radical polymerization (ICAR ATRP) is selected as illustrative polymerization technique with n‐butyl acrylate and methyl methacrylate as comonomers, aiming at the synthesis of well‐defined gradient copolymers. Using literature based model parameters, in particular temperature dependent monomer and radical reactivity ratios, it is demonstrated that PMU effects on propagation and ATRP (de)activation cannot be ignored to identify the most suited ICAR ATRP reactants (e.g., tertiary ATRP initiator) and reaction conditions (e.g., feeding rates under fed‐batch conditions). The formulated insights highlight the need for further research on PMU effects on all reaction steps in radical polymerization. © 2017 American Institute of Chemical Engineers AIChE J, 2017

Synthesis of PNVP-Based Copolymers with Tunable Thermosensitivity by Sequential Reversible Addition⁻Fragmentation Chain Transfer Copolymerization and Ring-Opening Polymerization.

Through the reversible addition–fragmentation chain transfer (RAFT) copolymerization of 3-ethyl-1-vinyl-2-pyrrolidone (C2NVP) and N-vinylpyrrolidone (NVP), a series of well-defined P(C2NVP-co-NVP) copolymers were synthesized (Mn = ca. 8000 to 16,000 and Mw/Mn <1.5) by using a difunctional chain transfer agent, S-(1-methyl-4-hydroxyethyl acetate) O-ethyl xanthate (MHEX). Copolymerizing kinetics and different monomer ratio in feeds were conducted to study the apparent monomer reaction rate and reactivity ratios of NVP and C2NVP, which indicated similar reaction rates and predominantly ideal random copolymers for the two monomers. The Tgs of the obtaining P(C2NVP-co-NVP) copolymers significantly corresponded to not only molecular weights MWs but also copolymer compositions. These copolymers presented characteristic lower critical solution temperatures (LCST) behavior. We then studied the cloud points (CPs) of the copolymers with varying MWs and compositions. With different MWs, the CPs were linearly decreased from ca. 51 to 45 °C. With different compositions, the CPs of the copolymers decreased from ca. 48 to 29 °C with C2NVP content (i.e., from 60.8 to 89.9 mol %). Fitting the CPs by the theoretical equation, the result illustrated that the introduction of more hydrophobic units of C2NVP suppressed the hydrophilic interaction between the polymer chain and water. We then successfully proceeded the chain extension through the ring-opening polymerization (ROP) of ε-caprolactone (CL) to the synthesis of a novel P(C2NVP-co-NVP)-b-PCL amphiphilic block copolymer (Mn,NMR = 14,730 and Mw/Mn = 1.59). The critical micelle concentration (CMC) of the block copolymer had a value of ca. 1.46 × 10−4 g/L. The block copolymer micelle was traced by dynamic light scattering (DLS), obtaining thermosensitive behaviors with a particle size of ca. 240 nm at 25 °C and ca. 140 nm at 55 °C, respectively.

Synthesis and characterization of poly (ε-caprolactam-co-lactide) polyesteramides using Brønsted acid or Brønsted base organocatalyst

Polyesteramides (PEAs) are considered intriguing materials due to the combination of the favorable degradable capacity of aliphatic polyesters given by the hydrolizable ester groups and the desirable thermal and mechanical behavior of polyamides given by the amide groups. Between polyamides and polyester families, poly(ε-caprolactam) and poly(l-lactide) stand out due to their commercial value and outstanding properties. Nevertheless, to date these two monomers have not been co-polymerized due to their different reactivities. In this work, we report for the first time, up to our knowledge, the synthesis of poly(ε-caprolactam-co-l-lactide) copolymers with different compositions. Two different catalysts: (a) Brønsted acid ionic liquid 1-(4-sulfobutyl)-3-methylimidazolium hydrogen sulfate (BAIL) and (b) Brønsted base P4-t-Bu have been explored. In the presence of Brønsted acid the l-lactide reactivity is higher than the ε-caprolactam while in the presence of Brønsted base the opposite behavior is observed. Using Kelen-Tudos method the monomer reactivity ratios are calculated and obtained as rCLa=0.39 and rLA=1.6 and rCLa=2.2 and rLA=0.1 using BAIL and P4-t-Bu, respectively. These differences in the monomer reactivity ratios give us the possibility to create copolymers with different chain microstructure depending on the employed catalyst between 2 and 9kDa. Thus, using P4-t-Bu random copolymers can be obtained at high l-lactide concentration and blocky character copolymers at high ε-caprolactam concentration. Meanwhile, using BAIL catalyst random like copolymers are obtained at high ε-caprolactam contents and blocky character at high l-lactide contents.

Effect of the Cationic Block Structure on the Characteristics of Sludge Flocs Formed by Charge Neutralization and Patching.

In this study, a template copolymer (TPAA) of (3-Acrylamidopropyl) trimethylammonium chloride (AATPAC) and acrylamide (AM) was successfully synthesized though ultrasonic-initiated template copolymerization (UTP), using sodium polyacrylate (PAAS) as a template. TPAA was characterized by an evident cationic microblock structure which was observed through the analyses of the reactivity ratio, Fourier transform infrared spectroscopy (FTIR), 1H (13C) nuclear magnetic resonance spectroscopy (1H (13C) NMR), and thermogravimetry/differential scanning calorimetry (TG/DSC). The introduction of the template could improve the monomer (AATPAC) reactivity ratio and increase the length and amount of AATPAC segments. This novel cationic microblock structure extremely enhanced the ability of charge neutralization, patching, and bridging, thus improving the activated sludge flocculation performance. The experiments of floc formation, breakage, and regrowth revealed that the cationic microblock structure in the copolymer resulted in large and compact flocs, and these flocs had a rapid regrowth when broken. Finally, the larger and more compact flocs contributed to the formation of more channels and voids, and therefore the specific resistance to filtration (SRF) reached a minimum.

Novel bioactive imidazole-containing polymeric surfactants as petroleum-collecting and dispersing agents: Synthesis and surface-active properties

Novel series of imidazole-containing polymers and polymeric surfactants have been synthesized via an efficient procedure. It included copolymerization of 1-vinyl-imidazole (VIM) with lauryl methacrylate (LMA) initiated by benzoyl peroxide and the 1H NMR spectroscopic data was utilized to estimate the monomer reactivity ratio. Conversion of polymers to surfactants was achieved through quaternization of the imidazole nitrogen with dimethyl sulphate. Spectroscopic techniques were used to elucidate the chemical structures of all synthesized compounds. The surface-active properties of polymeric surfactants beside their activities against various microbes were investigated. In addition, petroleum-collecting and dispersing properties of surfactants in diluted and undiluted form in varying waters were evaluated.

Improvement of Sludge Dewaterability by Ultrasound-Initiated Cationic Polyacrylamide with Microblock Structure: The Role of Surface-Active Monomers

Cationic polyacrylamides have been employed widely to improve sludge dewatering performance, but the cationic units are randomly distributed in the molecular chain, which restricts the further enhancement of dewaterability. Common template technology to prepare block copolymers requiring a huge number of templates reduces the polymer purity and molecular weight. Here, we adopted the surface-active monomer benzyl dimethyl 2-(methacryloyloxy)ethyl ammonium chloride (BDMDAC) to synthesize cationic microblocky polyacrylamide initiated by ultrasound. The reactivity ratio of monomers suggested that novel cationic monomer BDMDAC had higher homopolymerization ability, and was thus more prone to forming a microblock structure. The statistical analysis of sequence-length distribution indicated that the number and length of cationic segments increased in the PAB molecules. In addition, the characteristic results of Fourier transform infrared (FTIR), proton nuclear magnetic resonance (1H NMR), and thermogravimetric analysis (TGA) provided evidence for the synthesis of copolymer with cationic microblocks. Finally, the results of dewatering tests demonstrated that sludge dewaterability was greatly improved by adding the synthesized novel flocculants, and the sludge-specific resistance to filtration, filter cake moisture content and residual turbidity all reached a minimum (68.7%, 5.4 × 1012 m·kg−1, and 2.6 NTU, respectively) at 40 mg·L−1. The PAB flocs were large, compact, difficult to break, and easy to regrow. Furthermore, PAB was more effective in the removal of protein from soluble extracellular polymeric substances (SEPSs). In summary, this study provides a novel solution to synthesize cationic microblock polyacrylamide for improving sludge dewatering.

Superhydrophobic fluorinated acylonitrile coatings via electrospraying

The electrospraying of copolymers containing fluorinated acrylate and arylonitrile with different composition ratios was performed. Copolymers of 3,5-bis(perfluorobenzyloxy)benzyl acrylate (FM) monomer with arylonitrile (AN) were synthesized via free radical polymerization at 75 °C in dimethyformamide (DMF) using 2,2′-azobisisobutyronitrile (AIBN) as the initiator. Extended Kelen-Tüdos (EKT) method was utilized to calculate the monomer reactivity ratios. For the used monomer pair r1 was found as 0.11 for AN and r2 was found as 0.93 for FM. The result of r1.r2 < 1 indicates that the reaction went forward as random copolymerization. Molecular weights of the obtained copolymers were determined by gel permeation chromatography (GPC). 1H NMR spectroscopy is used for the characterization of the copolymers. The thermal behaviors of the copolymers were analyzed by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Copolymers showed one glass-transition temperature changing on the copolymer composition which indicated that copolymers were amorphous. Contact angle values of ethylene glycol and water on the films which were prepared by electrospraying process indicated superhydrophobic character. The crystallinity and surface morphology of the copolymers were described by X-ray diffraction (XRD) and scanning electron microscope (SEM) respectively.

Poly(vinylidene fluoride) Containing Phosphonic Acid as Anticorrosion Coating for Steel.

Vinylidene fluoride (VDF)-based copolymers bearing pendant phosphonic acid function for potential application as anticorrosion coatings were synthesized via free radical copolymerization of VDF with a new phosphorus containing 2-trifluoromethacrylate monomer, (dimethoxyphosphoryl)methyl 2-(trifluoromethyl)acrylate (MAF-DMP). MAF-DMP was prepared from 2-trifluoromethacrylic acid in 60% overall yield. Radical copolymerizations of VDF with MAF-DMP initiated by tert-amyl peroxy-2-ethylhexanoate at varying ([VDF]0/[MAF-DMP]0) feed ratios led to several poly(VDF-co-MAF-DMP) copolymers having different molar percentages of VDF (79-96%) and number-average molecular weights (Mn's) up to ca. 10 000 g mol-1 in fair yields (47-53%). Determination of the composition and microstructure of all the synthesized copolymers was done by 1H and 19F NMR spectroscopies. The monomer reactivity ratios of this new VDF/MAF-DMP pair were also determined (rVDF = 0.76 ± 0.34 and rMAF-DMP = 0 at 74 °C). The resulting poly(VDF-co-MAF-DMP) copolymers exhibited high melting temperature (162-171 °C, with respect to the VDF content), and the degree of crystallinity reached up to 51%. Finally, the pendant dimethyl phosphonate ester groups of the synthesized poly(VDF-co-MAF-DMP) copolymer were quantitatively hydrolyzed, giving rise to novel phosphonic acid-functionalized PVDF (PVDF-PA). In comparison to hydrophobic poly(VDF-co-MAF-DMP) copolymers (the water contact angle, WCA, was 98°), the hydrophilic character of the PVDF-PA was found to be surprisingly rather pronounced, exhibiting low WCA (15°). Finally, steel plates coated with PVDF-PA displayed satisfactory anticorrosion properties under simulated seawater environment.

Homopolymerization and synthesis of a new methacrylate monomer bearing a boron side group: characterization and determination of monomer reactivity ratios with styrene

Boron methacrylate (BAc) monomer was synthesized via an esterification reaction. Boric acid, neopentyl glycol, and 2-hydroxyethyl methacrylate (HEMA) were reacted to obtain boron-containing acrylic monomer. Characterization was achieved by FT-IR, $^{13}$C NMR, $^{1}$H NMR, and $^{11}$B NMR and the results for the synthesized monomer were compared to those for HEMA. Homopolymer and copolymers with styrene (St) were synthesized via free radical polymerization. The properties of the synthesized styrene copolymers were investigated using several techniques. Monomer reactivity ratios for the studied monomer pair were calculated using the extended Kelen-Tudos method. Copolymerization compositions and reactive ratios showed that the obtained copolymers had random characters. Thermal behaviors of the synthesized polymers were studied by thermal gravimetric analysis and differential scanning calorimetry methods. Boron methacrylate homopolymer showed one glass transition temperature at 73.7 $^{\circ}$C. Depending on copolymer composition, the glass transition temperatures of boron methacrylate-styrene copolymers were between 68.4 $^{\circ}$C and 81.5 $^{\circ}$C.

Studies on reactivity ratio and thermal studies of copolymers of N-substituted maleimide with vinyl pyridine [VP]/2-hydroxy ethylmethacrylate [OHEMA

The copolymers (C-NACPMI) with various proportions of N-[4-N'-(4-nitrophenyl) aminocarbonyl] phenyl) maleimide [NACPMI] with Vinyl Pyridine [VP] and 2-hydroxy ethylmethacrylate (OHEMA) were prepared by free radical polymerization. The structure of synthesized copolymers was characterized by FT - IR and 1 H-NMR spectroscopic methods. The nine copolymer samples were synthesized from different feed ratio of comonomers. The monomer reactivity ratio r NACPMI, r VP and r OHEMA are determined by Finemann Ross method. Copolymers showed solubility in polar solvent. Thermal behavior of copolymers was evaluated by TGA and DSC. The investigated copolymers degrade in one steps. The molecular weight was determined by GPC.

A Perfect Match: Fast and Truly Random Copolymerization of Glycidyl Ether Monomers to Thermoresponsive Copolymers

Thermoresponsive and highly biocompatible poly(glycidyl ether) copolymers of glycidyl methyl ether (GME) and ethyl glycidyl ether (EGE) with adjustable molecular weight and defined end groups are synthesized by a monomer-activated anionic ring-opening polymerization with NOct4Br as initiator and i-Bu3Al as activator. In contrast to a conventional oxyanionic (nonactivated) copolymerization, higher molecular weights and a truly random incorporation of the monomers are accomplished. The monomer reactivity ratios were determined by the Kelen–Tudos approach to be rGME = 0.98 and rEGE = 0.95. The thermoresponsive properties of these copolymers with varying molecular weight were characterized by UV–vis transmittance and dynamic light scattering. Conformational changes of the copolymer during the phase transition on the molecular level were studied by 1H and 13C NMR spectroscopy in D2O and revealed only a partial dehydration during the collapse of the copolymer affecting both side chains and polymer backbone.