Monomer Conversion Research Articles

Mechanical and microbiological properties of orthodontic resin modified with nanostructured silver vanadate decorated with silver nanoparticles (βAgVO3)

ObjectiveTo investigate the impact of incorporating the antimicrobial nanomaterial β-AgVO3 into orthodontic resin, focusing on degree of conversion, surface characteristics, microhardness, adhesion properties, and antimicrobial activity. MethodsThe 3 M Transbond XT resin underwent modification, resulting in three groups (Control, 2.5% addition, 5% addition) with 20 specimens each. Fourier transform infrared spectroscopy assessed monomer conversion. Laser confocal microscopy examined surface roughness, and microhardness was evaluated using Knoop protocols. Shear strength was measured before and after artificial aging on 36 premolar teeth. Microbiological analysis against S. mutans and S. sanguinis was conducted using the agar diffusion method. ResultsDegree of conversion remained unaffected by time (P = 0.797), concentration (P = 0.438), or their interaction (P = 0.187). The 5% group exhibited the lowest surface roughness, differing significantly from the control group (P = 0.045). Microhardness showed no significant differences between concentrations (P = 0.740). Shear strength was highest in the control group (P < 0.001). No significant differences were observed in the samples with or without thermocycling (P = 0.759). Microbial analysis revealed concentration-dependent variations, with the 5% group exhibiting the largest inhibition halo (P < 0.001). ConclusionsIncorporating β-AgVO3 at 2.5% and 5% concentrations led to significant differences in surface roughness, adhesion, and antimicrobial activity. Overall, resin modification positively impacted degree of conversion, surface characteristics, microhardness, and antimicrobial activity. Further research is warranted to determine clinically optimal concentrations that maximize antimicrobial benefits while minimizing adverse effects on adhesion properties. Clinical SignificanceIncorporating β-AgVO3 into orthodontic resin could improve patient quality of life by prolonging intervention durability and reducing the impact of cariogenic microorganisms. The study's findings also hold promise for the industry, paving the way for the development of new materials with antimicrobial properties for potential applications in the health sector.

Vinyl-addition copolymerization of norbornene and 1-octene catalyzed by a non-bridged half-titanocene with a tetrazole-phenoxy ligand

A catalyst system comprising Cp*TiCl2(OPhTz) (Cp* = C5Me5, OPhTz = tetrazole-mono-ortho-substituted phenoxy anion), iBu3Al, and [Ph3C][B(C6F5)4] is employed in the vinyl-addition copolymerization of norbornene (NB) and 1-octene (OT) to understand the catalytic effects of the N-donor tetrazole substituent. Copolymerization is accompanied by significant β-hydride elimination, producing poly(norbornene-co-1-octene) (P(NB-co-OT)) with low yield and molecular weight. Although the incorporation of OT into the copolymer is less than expected, competitive incorporation of the two monomers is observed. Increasing the mole fraction of OT in the feed reduces both the yield and molecular weight of the copolymer. Spectroscopic analysis reveals that the catalyst system yields P(NB-co-OT)s that are terminated prior to complete monomer conversion, along with non-isolated cooligomers and OT-derived isomers. The cationic titanium(IV) center stabilized by the N-donor tetrazole substituent facilitates the highly regioselective 2,1-insertion of OT. This slows subsequent monomer insertion, thereby promoting β-hydride elimination.

Sedimentation and Laser Light Scattering Methods for Quantifying Synthetic Tau Aggregation Propensity.

Tau aggregation assays detect and quantify the conversion of soluble tau monomers into species having filamentous or oligomeric structure. Assays for filamentous aggregates in cross-β-sheet conformation leverage optical, biochemical, or biophysical methods, each with their own advantages and throughput capacity. Here we provide protocols for two medium-throughput assays based on sedimentation and laser light scattering and compare their performance, their utility for characterizing tau aggregation dynamics, and their limitations relative to other approaches. Additionally, a protocol for transmission electron microscopy analysis is updated so as to be compatible with the truncated tau variants that have emerged as powerful tools for interrogating the structural basis of tau polymorphism. Together these methods contribute to a rich tool kit for interrogating tau aggregation kinetics and propensity over a wide range of experimental conditions.

IUPAC recommended experimental methods and data evaluation procedures for the determination of radical copolymerization reactivity ratios from composition data

The IUPAC method uses monomer composition, conversion, and copolymer composition to find reactivity ratios. Shown the optimal reactivity ratios in red and a 95% Confidence Interval in blue.

Helical polyamines.

Polymer microstructures rely on tacticity, yet exploration in polyamines has focused predominantly on atactic polymers. We introduce a method to synthesize a diverse library of ortho and para-cyanobenzenesulfonyl-activated-methyl aziridines using R, S, and racemic alaninol. Living anionic ring-opening polymerization of racemic sulfonyl aziridines yields soluble polymers, while enantiomerically-pure sulfonyl aziridines follow a dispersion polymerization with complete monomer conversion giving access to stereoblock copolymers. Removal of activation groups is achieved using dodecanethiol and tert-butylimino-tri(pyrrolidino)phosphorane to obtain isotactic or atactic linear polypropylene imines (LPPIs). High-purity L-PPIs are obtained in salt and neutral forms with high yields. Stereoblock copolymers of poly-R-block-S-polysulfonamides and respective polypropylene imine stereoblocks are synthesized, revealing helical structures in water influenced by the monomer type and sequence in CD spectroscopy. Molecular dynamics simulations confirm the helical nature of isotactic LPPIs in water. Bulk characterization demonstrates the first crystalline isotactic polyamines via spherulite growth in polarized light, atomic force microscopy and XRD analyses. In cell-transfection studies, the synthesized isotactic LPPIs exhibit lower toxicity and transfection efficiency than commercial hyperbranched polyethylene imine, with longer chains showing increased transfection efficiency. These isotactic polymers open avenues for complex macromolecular architectures with optically active polyamines akin to poly(amino acid)s but lacking hydrolytically cleavable amide links.

Block copolymer synthesis in ionic liquid via polymerisation-induced self-assembly: a convenient route to gel electrolytes.

We report for the first time a reversible addition-fragmentation chain transfer polymerisation-induced self-assembly (RAFT-PISA) formulation in ionic liquid (IL) that yields worm gels. A series of poly(2-hydroxyethyl methacrylate)-b-poly(benzyl methacrylate) (PHEMA-b-PBzMA) block copolymer nanoparticles were synthesised via RAFT dispersion polymerisation of benzyl methacrylate in the hydrophilic IL 1-ethyl-3-methyl imidazolium dicyanamide, [EMIM][DCA]. This RAFT-PISA formulation can be controlled to afford spherical, worm-like and vesicular nano-objects, with free-standing gels being obtained over a broad range of PBzMA core-forming degrees of polymerisation (DPs). High monomer conversions (≥96%) were obtained within 2 hours for all PISA syntheses as determined by 1H NMR spectroscopy, and good control over molar mass was confirmed by gel permeation chromatography (GPC). Nanoparticle morphologies were identified using small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM), and further detailed characterisation was conducted to monitor rheological, electrochemical and thermal characteristics of the nanoparticle dispersions to assess their potential in future electronic applications. Most importantly, this new PISA formulation in IL facilitates the in situ formation of worm ionogel electrolyte materials at copolymer concentrations >4% w/w via efficient and convenient synthesis routes without the need for organic co-solvents or post-polymerisation processing/purification. Moreover, we demonstrate that the worm ionogels developed in this work exhibit comparable electrochemical properties and thermal stability to that of the IL alone, showcasing their potential as gel electrolytes.

One-step flow synthesis of size-controlled polymer nanogels in a fluorocarbon microfluidic chip.

Synthetic polymer nanoparticles (NPs) with biomimetic properties are ideally suited for different biomedical applications such as drug delivery and direct therapy. However, bulk synthetic approaches can suffer from poor reproducibility and scalability when precise size control or multi-step procedures are required. Herein, we report an integrated microfluidic chip for the synthesis of polymer NPs. The chip could sequentially perform homopolymer synthesis and subsequent crosslinking into NPs without intermediate purification. This was made possible by fabrication of the chip with a fluorinated elastomer and incorporation of two microfluidic mixers. The first was a long channel with passive mixing features for the aqueous RAFT synthesis of stimuli-responsive polymers in ambient conditions. The polymers were then directly fed into a hydrodynamic flow focusing (HFF) junction that rapidly mixed them with a crosslinker solution to produce NPs. Compared to microfluidic systems made of PDMS or glass, our chip had better compatibility and facile fabrication. The polymers were synthesized with high monomer conversion and the NP size was found to be influenced by the flow rate ratio between the crosslinker solution and polymer solution. This allowed for the size to be predictably controlled by careful adjustment of the fluid flow rates. The size of the NPs and their stimuli-responses were studied using DLS and SEM imaging. This microfluidic chip design can potentially streamline and provide some automation for the bottom-up synthesis of polymer NPs while offering on-demand size control.

Precise Synthesis of Tetrablock Copolymers of Different Acrylamide Derivatives via Iterative Aqueous Cu(0)-Mediated Polymerization

The accessibility of specific synthesis of tetrablock copolymers is reported. In a specific synthesis, four acrylamide monomers are gradually added using an iterative aqueous Cu(0)-mediated reversible-deactivation radical polymerization (RDRP) method. Essential to the success of this approach is the ability to design and polymerize ABCD copolymer sequence with no need for immediate purification steps. The simple in-situ sequential polymerization method allowed for essentially perfect control of accurately well-defined tetrablock copolymers, which are composed of four tiny blocks, each of which contains an average of ten functional monomer units of acrylamide derivatives, resulting in a variety of functional groups. While the final molecular weight distributions have very narrow despersities (Đ &lt; 1.10), the efficient successive chain extension polymerization proceeded with high monomer conversions (&gt;99%), delivering excellent block purification in a short period of time. The tetrablock poly(NIPAM-DMA-HEAA-DEA) was characterized by NMR and GPC and showed beneficial end-group fidelity, allowing quantitative monitoring of the system’s alive nature after each synthetic cycle. Importantly, these one-pot syntheses are carried out at a below temperature of 0.0 °C in water as the solvent and can be implemented for applications of molecular biology. We also investigate the potential for a copper-amide complex to develop with acrylamide monomer, which could have an adverse effect on the end group’s functioning. Finally, we believe that this approach makes it easier to create a novel category of advanced polymeric materials.

Assessing the Efficacy of Novel Fiber-Reinforced Dual-Cure Luting Resins.

Dual-cure resin-based luting materials are increasingly favored in clinical applications due to their capacity to establish a strong bond with natural tooth structure and restorations. This study aimed to examine certain physical and handling characteristics of newly developed experimental dual-cure luting resins reinforced with short fibers (SFRCs) and compare them with commercially available dual-cure luting resins. Seven dual-cure luting materials were tested (Relyx Ultimate, Duo-Link, eCEMENT, Variolink Esthetic, G-CEM LinkForce, experimental SFRC1, experimental SFRC2). Fourier transform infrared spectroscopy (FTIR) was utilized to determine the degree of monomer conversion (DC%) in the self and light-curing protocol. A rotating disk rheometer measured viscosity at room temperature (22°C) and simulated mouth temperature (35°C). Fracture toughness, flexural strength, and flexural modulus were evaluated using a 3-point bending test. Each luting resin was subjected to the examination of its surface microstructure using scanning electron microscopy (SEM). Analysis of variance (ANOVA) at a significance level of (p = 0.05) was conducted to analyze data. It was revealed that DC% of the tested dual-cure resins was significantly (p< 0.05) affected by the curing mode, the dual-cure SFRC2 having the highest and Relyx having the lowest DC (64%, and 41% respectively). The viscosity of all tested materials decreased with increasing temperature. SFRC2 demonstrated the highest fracture toughness (2.3 MPa m1/2), while Relyx Ultimate, Duo-Link, and eCEMENT exhibited the lowest values (≈ 1 MPa m1/2)(p< 0.05). Both SFRCs and G-CEM link-force exhibited the highest flexural strength values, and SFRCs resulted in the highest flexural modulus values (p<0.05). The experimental fiber-reinforced dual-cure luting resins exhibited superior DC%, fracture toughness, and flexural properties, yet, SFRC2 showed the highest viscosity at elevated temperature. These results highlight the capability of short fiber reinforcement to enhance the mechanical properties of dual-cured resin-based luting materials without compromising handling characteristics. Key words:Dual-cure luting resin; short fibers; degree of conversion; viscosity; fracture toughness; flexural properties.

Enhanced synthesis of multiblock copolymers via acid-triggered RAFT polymerization.

The synthesis of multiblock copolymers has emerged as an efficient tool to not only reveal the optimal way to access complex structures and investigate polymer properties but also to ascertain the end-group fidelity of a given polymerization methodology. Although reversible addition-fragmentation chain-transfer (RAFT) polymerization is arguably the most dominant strategy employed, its success is often hampered by the unavoidable and excessive use of radical initiators which results in increased termination and loss of end-group fidelity. In this work, we employ acid in RAFT polymerization to enhance the synthesis of multiblock copolymers. By the addition of a small amount of acid, a 4-fold decrease in the overall required radical initiator concentration was achieved, enabling the synthesis of a range of well-defined multiblock copolymers with various degrees of polymerization (DP) per block. The acid enhances the propagation rate, minimizing the initiator concentration. In all cases, near-quantitative monomer conversion was obtained (>97%) for every iterative block formation step. Notably, and in contrast to conventional RAFT approaches, the tailing to low molecular weight was significantly suppressed and the dispersity was maintained nearly constant (i.e. in most cases Đ = 1.1-1.2), thus indicating minor termination events and side reactions during acid-enhanced synthesis. The possibility to synthesize multiblocks consisting of methacrylates, acrylates, and acrylamides was also demonstrated. This work presents an advancement in the synthesis of well-defined multiblock copolymers and more broadly, RAFT polymers with high end-group fidelity.

Mechanically induced cationic reversible addition-fragmentation chain transfer polymerization of vinyl ethers.

Mechanoredox catalysis has emerged as a sustainable approach for organic transformations. Mechanically controlled polymerization that uses mechanoredox catalysts enables synthesis of complex polymers and mechanoresponsive materials with diverse applications. Despite its potential, the focus has predominantly been on free radical polymerization and acrylate monomers. The mechanochemical synthesis of poly(vinyl ether)s (PVEs) poses a significant challenge in the field. Herein, we report an efficient mechanically induced cationic reversible addition-fragmentation chain transfer (mechano-cRAFT) polymerization using 2D MoS2 as a mechanoredox catalyst, where free radical intermediates can be further oxidized to cations to promote cationic polymerization of vinyl ethers. This mechano-cRAFT polymerization can be conducted in air and with minimal organic solvent, resulting in quantitative monomer conversion. This strategy is applicable to a range of vinyl ether monomers, yielding polymers with controlled molecular weight and narrow dispersity. We also performed trapping experiments to investigate the piezoelectrically mediated redox process, and further validated the mechanism through density functional theory (DFT) calculations.

A mini-review on different polymerization protocols for resin-based dental composites

Biocompatibility is one of the major prerequisites for safe clinical application of materials. Dental resin composites may release their components into oral environment, which can lead to adverse reactions. Several studies have identified that many organic components of composites resin, such as bisphenol-A-glycidyl-methacrylate (Bis-GMA), triethylene glycol dimethacrylate (TEGDMA), urethane dimethacrylate (UDMA) and 2-hydroxyethyl methacrylate (HEMA) show a cytotoxic profile. Cytotoxicity is mainly sustained by free monomers released after polymerization process. Direct restorations are polymerized at body temperature by visible light emitting lamps, but the conversion from monomer to polymer after light-curing is never complete. To improve the degree of conversion of resin-based composites, additional curing protocols performed at increased temperatures, such as heat-curing, can be employed. Polymerization reaction plays a key role in the conversion of the free monomers into polymers and resin-based composites with high degree of conversion might show higher biocompatibility. The aim of this mini-review is to report current knowledge about the cytotoxicity of different composite resins, cured in two different ways. Further studies are necessary to better understand the relationship between the cytotoxicity and the degree of polymerization of resin-based composites.

바이오매스 회분 촉매 열분해를 통한 폐 EPS(Expanded polystyrene)의 스티렌 모노머 전환 최적 조건 도출 연구

바이오매스 회분 촉매 열분해를 통한 폐 EPS(Expanded polystyrene)의 스티렌 모노머 전환 최적 조건 도출 연구

Correlation between shear bond strength and degree of conversion of four orthodontic adhesives.

Background and objective: The study aims to assess the correlation between degree of monomer conversion (DC) and shear bond strength (SBS) of the different adhesives. The objective of the present study was to determine the efficiency of four orthodontic adhesives regarding shear bond strength (SBS), debonding characters and degree of conversion (DC) and to correlate SBS to the DC. Methods: Forty human upper first premolars, divided into four Groups (n = 10) were bonded with metal brackets using four different adhesives. Brackets were debonded in shear on an Instron universal testing machine with a crosshead speed of 1 mm per minute. The mode of bond failure was determined by the adhesive remnant index (ARI) index and the DC was determined by Fourier transform infrared spectroscopy (FTIR) analysis. Result: There was a statistically significant difference between the SBS of only Transbond XT and Orthobond plus color change adhesive while the two remaining adhesives showed no significant difference. All groups of adhesives showed a cohesive type of bond failure according to the ARI results. A statistically significant lower percentage of DC was noted for Orthobond plus (63 %) than Transbond XT (70.2 %) but it was within the accepted range reported in the literature (55-75%). Pearson’s correlation was significantly positive between SBS and DC for Smart Ortho, Heliosit Orthodontic and Orthobond Plus adhesives and insignificantly positive for Transbond XT. Conclusion: Within the limitations of this in vitro study it can be concluded that the Transbond plus color change has significantly higher fluoride release as well as recharge properties when compared to other ortho-adhesive materials. Keywords: Orthodontic Adhesive, Shear Bond Strength, Degree of conversion

Light transmittance through resin-matrix composite onlays adhered to resin-matrix cements or flowable composites

ObjectiveThe aim of this study was to evaluate the influence of the thickness of resin-matrix composite blocks manufactured by CAD-CAM on the light transmittance towards different resin-matrix cements or flowable composites. MethodsSixty specimens of resin-matrix composite CAD-CAM blocks reinforced with 89 wt% inorganic fillers were cross-sectioned with 2 or 3 mm thicknesses. The specimens were conditioned with adhesive system and divided in groups according to the luting material, namely: two dual-cured resin-matrix cements, two traditional flowable resin-matrix composites, and one thermal-induced flowable resin-matrix composite. Specimens were light-cured at 900 mW/cm2 for 40s. Light transmittance assays were preformed using a spectrophotometer with an integrated monochromator before and after light-curing. Microstructural analysis was performed by optical and scanning electron microscopy (SEM). Nanoindentation tests were performed to evaluate mechanical properties for indirect evaluation of degree of monomers conversion. ResultsOptical and SEM images revealed low thickness values for the cementation interfaces for the traditional flowable resin-matrix composite. The cement thickness increased with the size and content of inorganic fillers. The highest light transmittance was recorded for the onlay blocks cemented with the traditional flowable resin-matrix composites while a group cemented with the dual-cured resin-matrix cement revealed the lowest light transmittance. The elastic modulus and hardness increased for specimens with high content of inorganic fillers as well as it increased in function of the light transmittance. ConclusionsThe light transmittance of flowable resin-matrix composites was higher than that for resin-matrix cement after cementation to resin-matrix composites blocks. The type, size, and content of inorganic fillers of the luting material affected the thickness of the cement layer and light transmittance through the materials. Clinical relevanceOn chair-side light curing, the transmission of visible light can be interfered by the chemical composition and viscosity of the luting materials. The increase in size and content of inorganic fillers of resin-matrix composites and luting materials can decrease the light transmittance leading to inefficient polymerization.

Controlled polymerization in microfluidics: Advancement in nanogel synthesis

AbstractThis comprehensive review provides a detailed examination of controlled polymerization in the development of nanogels‐based microfluidic devices. Here, we have explored the integration of atom transfer radical polymerization (ATRP) and reversible addition‐fragmentation chain transfer (RAFT) techniques within microfluidic platforms for the synthesis of nanogels. The synergistic combination of ATRP and RAFT with microfluidics has emerged as a powerful tool for precise control over polymerization reactions, enabling the fabrication of well‐defined, multifunctional nanogels with tailored properties. The review begins with a thorough introduction to the principles of ATRP and RAFT, highlighting their respective advantages in controlled radical polymerization. Subsequently, it elucidates the principles of microfluidics and its profound impact on polymerization processes. The merging of these techniques enables precise control over reaction kinetics, monomer conversions, and molecular weight distributions, facilitating the synthesis of nanogels with unprecedented precision and reproducibility. Furthermore, this review delves into the chemical mechanisms underlying ATRP and RAFT reactions in microfluidic environments, emphasizing the role of various initiators, catalysts, and chain transfer agents. Special attention is given to the impact of microscale flow conditions on reaction kinetics and polymer structure. In addition, the review discusses emerging trends in the field, such as the incorporation of novel monomers and the exploration of environmentally benign reaction conditions.Highlights The controlled polymerization is the mechanism by which we can obtain tailormade material. The nanogel synthesis must ensure the gelation to be in confined dimensions here microfluidics plays key role.

Titanium and Vanadium Complexes of Tridentate Phenoxy-Imine and Phenoxy-Amine Ligands and Their Application in the Ring-Opening Polymerization of Cyclic Esters.

Phenoxy-imine and phenoxy-amine proligands, with the additional OH donor groups 2,4-tBu2-6-(2-CH2(OH)-C6H4N=CH)C6H3OH (L1H2), 6-(2-CH2(OH)-C6H4N=CH)C6H3OH (L2H2), and 2,4-tBu2-6-(2-CH2(OH)-C6H4NH-CH)C6H3OH (L3H2), were synthesized and their titanium (Ti-L1-Ti-L3) and vanadium (V-L1-V-L2) complexes were prepared in reactions with Ti(OiPr)4 and VO(OiPr)3, respectively. All new compounds were characterized with the use of FTIR, 1H, and 13C NMR spectroscopy; X-ray crystallography was also used to study proligands. All the complexes proved to be active catalysts in the ring-opening polymerization (ROP) of ε-caprolactone, rac-lactide, and L-lactide in the melt. The effects of the complex structure (transition metal type, presence of tBu substituents, and type of nitrogen donor group), as well as the polymerization time and temperature, on the monomer conversion and polymer properties were investigated in detail.

Hydrodepolymerization of lignin with Ni supported on active carbon catalysts reduced at different temperatures

Various Ni supported on active carbon (Ni/AC) catalysts were acquired by reduced at different temperatures, among which Ni/AC-500 possesses the smallest particle sizes of metallic Ni species, favoring to more active sites exposed on the catalyst surface, and the suitable content of metallic Ni0, implying the high hydrogenolysis activity obtained. Additionally, the highest mesoporous volume of Ni/AC-500 promotes the diffusion of large molecules from lignin depolymerization. Therefore, Ni/AC-500 exhibits the higher lignin conversion and yields of liquid bio-oil and monomers, but the lower yield of bio-char in lignin hydrodepolymerization due to its higher hydrogenolysis activity compared with other catalysts.

Functional Acrylic Resins Prepared via Photo-Induced Telomerization Using Tetrabromomethane as Telogen.

Novel method of obtaining functional acrylic resins (FARs) containing carboxyl- and benzophenone groups (in-chain functionalization) and terminal Br atoms was verified. Acrylic oligomers were prepared by a solution-free, UV-initiated telomerization process of basic monomer (n-butyl acrylate) and functional monomers (acrylic acid and 4-acrylooxybenzophenone) in the presence of radical photoinitiator and different amount of tetrabromomethane (CBr4) as telogen. The effect of telogen content on UV-telomerization kinetics as well as physicochemical and thermal (Tg) properties of FARs was investigated. A telogen content higher than 5 wt. parts does not affect the UV-telomerization rate (photo-DSC), the molecular weights of telomers (GPC), or their glass transition temperature (DSC), but it significantly increases the conversion of monomers (up to 88%) and lowers the viscosity of FARs (approx. 6 Pa·s). NMR studies confirmed the inclusion of CBr4 in the structure of functional acrylic telomers.

Synthesis, kinetic study and characterization of C5‐dienes/styrene copolymers via living anionic polymerization in cyclopentyl methyl ether solvent

Abstract1,3‐Dienes/styrene sequence‐controlled copolymers are widely used as thermoplastic elastomers, transparent impact resin and synthetic rubber and other materials. In this work, the binary anionic copolymerization of styrene (S) and C5‐dienes including 1,3‐pentadiene (P, E/Z = 65/35) and isoprene (I) were studied in cyclopentyl methyl ether (CPME) ‘green’ solvent using n‐BuLi as initiator, and the effects of copolymerization monomer ratio and polar additive (PA) on the copolymerization kinetics and monomer sequence distributions were investigated. The kinetic analysis results showed that all copolymerization systems were the first‐order reaction and the C5‐dienes/S could be quantitatively consumed. The addition of S or I was conducive to the efficient conversion of P. Although the addition of PAs had little effect on the polymerization rate, it had a great influence on the microstructure and sequence distribution of the copolymer. 1H NMR tracking analysis showed that, for S/P copolymerization with different feeding ratios 1/3 &lt; fP &lt; 2/3, the instant composition FP in the copolymer remained relatively constant at 15% &lt; FP &lt; 35% when the monomer conversion rate was below 60%, and thus the inevitable formation of P microblocks in subsequent polymerization sequences was observed. Additionally, similar sequence distributions were obtained in the case of I/P copolymerization systems. By contrast, S/I copolymerization conformed to the typical random copolymerization pattern, and the copolymerization activity of S was slightly higher than that of the I in CPME. The use of strong PAs such as 2,2‐di(2‐tetrahydrofuran)propane directly resulted in a change of monomer sequence from a random pattern to a gradual block pattern. Moreover, the 3,4‐isoprene branch units were much more sensitive to solvent and PA than 1,2‐pentadiene units for C5‐dienes; also Fourier transform infrared and DSC analysis verified the microstructure and sequence analysis results mentioned above. In addition, the results of gel permeation chromatography showed that the copolymerization process in CPME had excellent controllable characteristics. © 2023 Society of Industrial Chemistry.