Binary Copolymerization Research Articles

The effect of chain transfer reactions on the relative activity of monomers in radical copolymerization

A scientific hypothesis on the effect of chain transfer reactions on the relative activity of monomers in radical copolymerization is theoretically substantiated. It is concluded that when binary copolymerization of monomers is carried out in the presence of active chain carriers, the compositional homogeneity of the obtained copolymers will deteriorate.

Monomer Transport in Emulsion Polymerization III Terpolymerization and Starved‐Feed Polymerization

AbstractA simple mathematical model of the transport of monomer from the monomer droplets to the polymerizing polymer particles during batch emulsion homopolymerization has been developed and published previously. A Damkohler number for monomer transport in emulsion polymerization is proposed as the ratio of the maximum rate of polymerization divided by the maximum rate of monomer transport out of the monomer droplets. This Damkohler number is calculated from literature values for a number of common monomers. Following standard practice for the use of such a Damkohler number in other reaction‐with‐transport systems, monomers with a Damkohler number above 0.1 are considered to be transport limited. In a third paper the analysis is extended to batch binary copolymerization. Here the analysis is extended to the more industrially relevant cases of batch terpolymerization, starved‐feed copolymerization, and the combination of the two (starved‐feed terpolymerization).

PREPARATION OF OPTICAL TRANSPARENT COMPOSITES ON THE BASIS OF BUTYL METHACRYLATE WITH -METHYL STYRENE

The process of radical binary copolymerization of butyl methacrylate and α-methyl styrene in a solvent has been carried out and optically transparent copolymers at various molar ratios have been synthesized. The copolymers synthesized based on butyl methacrylate and α-methyl styrene have relatively high refraction coefficient ( =1.5880) and transmission values (about 86%). The copolymerization constants values (r1 and r2) of the above-mentioned monomer pairs have been found and Q-e parameters have been calculated. The microstructure of the obtained copolymer samples of the butyl methacrylate with α-methyl styrene has been determined

Theoretical analysis of RNA polymerase fidelity: a steady-state copolymerization approach

The fidelity of DNA transcription catalyzed by RNA polymerase (RNAP) has long been an important issue in biology. Experiments have revealed that RNAP can incorporate matched nucleotides selectively and proofread the incorporated mismatched nucleotides. However, systematic theoretical researches on RNAP fidelity are still lacking. In the last decade, several theories on RNA transcription have been proposed, but they only handled highly simplified models without considering the high-order neighbor effects and the oligonucleotides cleavage both of which are critical for the overall fidelity. In this paper, we regard RNA transcription as a binary copolymerization process and calculate the transcription fidelity by the steady-state copolymerization theory recently proposed by us for DNA replication. With this theory, the more realistic models considering higher-order neighbor effects, oligonucleotides cleavage, multi-step incorporation and multi-step cleavage can be rigorously handled.

Determination of Reactivity Ratios from Binary Copolymerization Using the k-Nearest Neighbor Non-Parametric Regression.

This paper proposes a new method for calculating the monomer reactivity ratios for binary copolymerization based on the terminal model. The original optimization method involves a numerical integration algorithm and an optimization algorithm based on k-nearest neighbour non-parametric regression. The calculation method has been tested on simulated and experimental data sets, at low (<10%), medium (10–35%) and high conversions (>40%), yielding reactivity ratios in a good agreement with the usual methods such as intersection, Fineman–Ross, reverse Fineman–Ross, Kelen–Tüdös, extended Kelen–Tüdös and the error in variable method. The experimental data sets used in this comparative analysis are copolymerization of 2-(N-phthalimido) ethyl acrylate with 1-vinyl-2-pyrolidone for low conversion, copolymerization of isoprene with glycidyl methacrylate for medium conversion and copolymerization of N-isopropylacrylamide with N,N-dimethylacrylamide for high conversion. Also, the possibility to estimate experimental errors from a single experimental data set formed by n experimental data is shown.

Features of radical copolymerization initiated by manganese triacetylacetonate

A comprehensive study of the kinetics of reactions of binary copolymerization of vinyl acetate with N-vinyl (N-vinylsuccinimide and N-vinyl-3(5)-methylpyrazole) and acrylic (2-hydroxyethylmethacrylate) monomers in different media was conducted. It is shown that the use of manganese triacetylacetonate as an initiator makes it possible to bring together the relative activities of monomers due to the complexation of manganese trisacetylacetonate and vinyl acetate molecules. This leads to a change in the microstructure of copolymers and to the production of macrochains with improved interleaving of monomeric links.

Monomer Transport in Emulsion Polymerization II: Copolymerization

AbstractThe method for evaluating the Damkohler number for monomer transport during emulsion homopolymerization is extended to copolymerization. It is shown that monomers that are not monomer‐transport limited during homopolymerization may become more so during binary copolymerization, and monomers that are monomer‐transport limited during homopolymerization may become less so during binary copolymerization.

Switchable circularly polarized Room-Temperature phosphorescence based on pure organic amorphous binaphthyl polymer

• Circularly polarized room temperature phosphorescence obtained in copolymers. • Phosphorescence switch induced by acid-based regulated external heavy atom effect. • Double encryption application based on phosphorescence lifetime discrimination. The development of circularly polarized luminescence (CPL) materials has attracted much attention because of their potential application in chiral recognition and optical device. However, current achievements mainly focus on circularly polarized fluorescence, and circularly polarized room temperature phosphorescence (CPRTP) materials remain a great challenge especially the pure organic amorphous CPRTP materials. Herein, a CPL and CPRTP pure organic amorphous polymer R/S-BPNaP are developed by radical binary copolymerization of acrylamide and chiral binaphthyl derivates. More interestingly, the copolymers show tunable acid-base responsive switching RTP emission properties and can be applied in the area of encryption.

A model for producing polymer stabilizers of composites with a given macromolecule composition

An attempt has been made to obtain a working technological formula that regulates the addition of comonomer over time, which ensures the synthesis of a copolymer macromolecule with a constant composition and, accordingly, with predicted properties of both the copolymer and its modified porous composite materials. Mathematical modeling is based on the theory of the kinetics of copolymerization, which takes into account the reactivity of monomers by means of copolymerization constants of reacting comonomers. The starting base was the kinetics of the copolymerization of two comonomers, significantly differing in their reactivity, which required a sequential, stepwise supply of a less reactive monomer to the reaction medium with a more active monomer. This technological technique contributes to maintaining the constancy of the initial ratio of comonomers and, accordingly, the synthesis of a copolymer with a constant composition, structure and properties. The dependence of the sequence of supply of comonomer to the reaction medium required the introduction of a generalized effective binary copolymerization rate coefficient. To find the generalized coefficient of the copolymerization rate, the operation of logarithm was performed and the current expression of the dependence of the concentration change of the more active monomer in time in a linear form was translated. This mathematical technique made it possible to use software to process reference information to obtain the necessary coefficients for the working formula. As a result of mathematical modeling using the basic principles of binary copolymerization, the law of effective masses, and the least squares method, a working formula is obtained that allows one to regulate the given introduction of a less active monomer into the reaction medium in time. The model is analyzed using background information, the basic concepts of binary copolymerization and can be used in technological calculations when producing copolymers with specified characteristics in composition and structure.

Study on MMA and BA Emulsion Copolymerization Using 2,4-Diphenyl-4-methyl-1-pentene as the Irreversible Addition-Fragmentation Chain Transfer Agent.

As a chain transfer agent, 2,4-diphenyl-4-methyl-1-pentene (αMSD) was first introduced in the emulsion binary copolymerization of methyl methacrylate (MMA) and butyl acrylate (BA) based on an irreversible addition–fragmentation chain transfer (AFCT) mechanism. The effects of αMSD on molecular weight and its distribution, the degree of polymerization, polymerization rate, monomer conversion, particle size, and tensile properties of the formed latexes were systematically investigated. Its potential chain transfer mechanism was also explored according to the 1H NMR analysis. The results showed that the increase in the content of αMSD could lead to a decline in molecular weight, its distribution, and the degree of polymerization. The mass percentage of MMA in the synthesized polymers was also improved as the amounts of αMSD increased. The chain transfer coefficients of αMSD for MMA and BA were 0.62 and 0.47, respectively. The regulation mechanism of αMSD in the emulsion polymerization of acrylates was found to be consistent with Yasummasa’s theory. Additionally, monomer conversion decreased greatly to 47.3% when the concentration of αMSD was higher than 1 wt% due to the extremely low polymerization rate. Moreover, the polymerization rate was also decreased probably due to the desorption and lower reactivity of the regenerative radicals from αMSD. Finally, the tensile properties of the resulting polyacrylate films were significantly affected due to the presence of αMSD.

Mapping binary copolymer property space with neural networks.

The extremely large number of unique polymer compositions that can be achieved through copolymerisation makes it an attractive strategy for tuning their optoelectronic properties. However, this same attribute also makes it challenging to explore the resulting property space and understand the range of properties that can be realised. In an effort to enable the rapid exploration of this space in the case of binary copolymers, we train a neural network using a tiered data generation strategy to accurately predict the optical and electronic properties of 350 000 binary copolymers that are, in principle, synthesizable from their dihalogen monomers via Yamamoto, or Suzuki-Miyaura and Stille coupling after one-step functionalisation. By extracting general features of this property space that would otherwise be obscured in smaller datasets, we identify simple models that effectively relate the properties of these copolymers to the homopolymers of their constituent monomers, and challenge common ideas behind copolymer design. We find that binary copolymerisation does not appear to allow access to regions of the optoelectronic property space that are not already sampled by the homopolymers, although it conceptually allows for more fine-grained property control. Using the large volume of data available, we test the hypothesis that copolymerisation of 'donor' and 'acceptor' monomers can result in copolymers with a lower optical gap than their related homopolymers. Overall, despite the prevalence of this concept in the literature, we observe that this phenomenon is relatively rare, and propose conditions that greatly enhance the likelihood of its experimental realisation. Finally, through a 'topographical' analysis of the co-polymer property space, we show how this large volume of data can be used to identify dominant monomers in specific regions of property space that may be amenable to a variety of applications, such as organic photovoltaics, light emitting diodes, and thermoelectrics.

Real‐Time Detection of Atmosphere Composition in Three‐Component Gas‐Phase Copolymerization of Olefins

AbstractThe uniformity of copolymer composition has a great influence on its properties; however, it is very difficult to control. Especially in the laboratory research of the multi‐component gas‐phase copolymerization of olefins, the polymerization is usually conducted in a batch reactor, and the composition of the resulting copolymers is often distributed very widely. The samples of such copolymers are in fact not representative. Detection and control of the atmospheric composition in the batch reactor during olefin gas‐phase copolymerization is of great significance for the control of the uniformity of copolymer composition. In this work, a method based on three flow meters in series has been developed for real‐time detection of the atmospheric composition in olefin gas‐phase copolymerization with a delay time of less than 3 s. The method is applicable to copolymerization of up to a ternary system, including the binary copolymerization of olefins with hydrogen modulation of molecular weight or the ternary copolymerization of olefins. The consumption rate of each monomer is also online measured.

Amorphous Pure Organic Polymers for Heavy‐Atom‐Free Efficient Room‐Temperature Phosphorescence Emission

AbstractPure organic, heavy‐atom‐free room‐temperature phosphorescence (RTP) materials have attracted much attention and have potential applications in photoelectric and biochemical material fields owing to their rich excited state properties. They offer long luminescent lifetime, diversified design, and facile preparation. However, recent achievements of efficient phosphorescence under ambient conditions mainly focus on ordered crystal lattices or embedding into rigid matrices, which require strict growth conditions and have poor reproducibility. Herein, we developed a concise approach to give RTP with a decent quantum yield and ultralong phosphorescence lifetime in the amorphous state by radical binary copolymerization of acrylamide and different phosphors with oxygen‐containing functional groups. The cross‐linked hydrogen‐bonding networks between the polymeric chains immobilize phosphors to suppress non‐radiative transitions and provide a microenvironment to shield quenchers.

Amorphous Pure Organic Polymers for Heavy-Atom-Free Efficient Room-Temperature Phosphorescence Emission.

Pure organic, heavy-atom-free room-temperature phosphorescence (RTP) materials have attracted much attention and have potential applications in photoelectric and biochemical material fields owing to their rich excited state properties. They offer long luminescent lifetime, diversified design, and facile preparation. However, recent achievements of efficient phosphorescence under ambient conditions mainly focus on ordered crystal lattices or embedding into rigid matrices, which require strict growth conditions and have poor reproducibility. Herein, we developed a concise approach to give RTP with a decent quantum yield and ultralong phosphorescence lifetime in the amorphous state by radical binary copolymerization of acrylamide and different phosphors with oxygen-containing functional groups. The cross-linked hydrogen-bonding networks between the polymeric chains immobilize phosphors to suppress non-radiative transitions and provide a microenvironment to shield quenchers.

Synthesis of Terpolymers with Homogeneous Composition by Free Radical Copolymerization of Maleic Anhydride, Perfluorooctyl and Butyl or Dodecyl Methacrylates: Application of the Continuous Flow Monomer Addition Technique.

Terpolymers of homogeneous composition were prepared by free radical copolymerization of butyl or dodecyl methacrylate, 1H,1H,2H,2H-perfluorodecyl methacrylate and maleic anhydride using the continuous monomer addition technique. The copolymerization reactions were performed at 65 °C in the presence of azobisisobutyronitrile as an initiator in a mixture of methyl ethyl ketone and 1,3-bis (trifluoromethyl)benzene. The monomers and initiator are added to the reaction mixture with the same rate they are consumed in 5- and 10-fold excess compared to the initial monomer stock. The obtained terpolymers with molecular weights Mn = 50,000–70,000 are of uniform composition, close to the composition determined in low conversion experiments, proving the principle of the chosen concept. The kinetic data necessary for the design of the continuous addition experiment were obtained from binary copolymerization experiments at low monomer conversion (to avoid compositional drift). In addition, the so-called terpolymerization parameter was determined from ternary copolymerization experiments.

Stereoselective polymerization of biosourced terpenes β-myrcene and β-ocimene and their copolymerization with styrene promoted by titanium catalysts

The stereoselective polymerization of β-myrcene and β-ocimene and their binary copolymerization with styrene promoted by titanium complexes dichloro{1,4-dithiabutanediyl-2,2′-bis(4,6-di-tert-butyl-phenyl)}titanium (1), dichloro{1,4-dithiabutanediyl-2,2′-bis[4,6-bis(2-phenyl-2-propyl)phenoxy]}titanium (2) and Ti(η5-C5H5)-(η2-MBMP)Cl (3) (MBMP = 2,2'methylenebis(6-tert-butyl-4-methylphenoxo)) activated by methylaluminoxane (MAO) is reported. Complex 1 produces a prevalently trans-1,4-polymyrcene (92%), the more sterically encumbered pre-catalyst 2 gives a major amount of 3,4-units (40%). Conversely the pre-catalyst 3 produces cis-1,4-polymyrcene with good selectivity (92%). The catalyst 1 promotes the copolymerization of β-myrcene with styrene giving the corresponding copolymers in a wide range of composition (χs = 0.14–0.90). In the case of β-ocimene the catalysts 1 and 2 produce a polymer with 1,4-trans structure (70%) at 70 °C while at lower temperature (0 °C) an isotactic poly-1,2-ocimene (>99%) is obtained. The catalyst 3 produces a less stereoregular polymer with prevalently cis-1,4-microstructure (55%). The catalyst 2 also promotes the copolymerization of β-ocimene with styrene in a wide range of composition (χs = 0.23–0.87).

Copolymerization of vinyl acetate initiated by manganese tris(acetylacetonate)

Vinyl acetate forms a complex with manganese tris(acetylacetonate). A scientific hypothesis, according to which the use of manganese tris(acetylacetonate) as an initiator would lead to the increase in the relative activity of vinyl acetate in copolymerization with more active monomers, is suggested. To verify the hypothesis experimentally, an integrated study of the kinetics of binary copolymerization of vinyl acetate with N-vinyl (N-vinylsuccinimide and N-vinyl-3(5)methylpyrazole) and acrylic (2-hydroxyethyl methacrylate) monomers in various media is carried out. It is demonstrated on the basis of an analysis of copolymerization constants of the monomers under study that the relative activities of monomers in fact become closer. This leads to a change of the microstructure of polymers and results in macrochains with improved alteration of monomer units.

Eugenol as renewable comonomer compared to 4-penten-1-ol in ethylene copolymerization using a palladium aryl sulfonate catalyst

A series of binary copolymerizations of ethylene with two comonomers, eugenol and 4-penten-1-ol, were conducted with a single-component palladium aryl phosphine sulfonate catalyst in toluene solution. Eugenol showed a much a higher tolerance by the catalyst than 4-penten-1-ol. Peak assignments for 1H NMR and 13C NMR spectra of both types of copolymers were established. Eugenol was incorporated into the copolymer at a higher rate compared to 4-penten-1-ol. Both comonomers were mainly inserted into the polymer chains rather than added as end groups. An end group analysis was performed, based on which some conclusions about the polymerization mechanisms were made. The molecular weight properties of the polymers were measured by GPC. The effects of each comonomer on the polymer crystallinity and melting temperature were determined. Antibacterial efficiency tests showed that copolymers containing more than 3.1 % eugenol resulted in a reduction of bacteria exceeding 90 %.

Binary copolymerization of 4-methyl-1,3-pentadiene with styrene, butadiene and isoprene catalysed by a titanium [OSSO]-type catalyst

Binary copolymerization of 4-methyl-1,3-pentadiene (4MPD) with styrene, butadiene and isoprene promoted by the titanium complex dichloro{1,4-dithiabutanediyl-2,2′-bis[4,6-bis(2-phenyl-2-propyl)phenoxy]}titanium activated by methylaluminoxane is reported. All the copolymers are obtained in a wide range of composition and the molecular weight distributions obtained from gel permeation chromatographic analysis of the copolymers are coherent with the materials being copolymeric in nature. The copolymer microstructure was fully elucidated by means of 1H NMR and 13C NMR spectroscopy. Differential scanning calorimetry shows an increase of glass transition temperature (Tg) with the amount of 4MPD in the copolymers with butadiene and isoprene, while in the copolymers with styrene Tg is increased on increasing the amount of styrene. © 2016 Society of Chemical Industry

Complex-Radical Terpolymerization of Maleic Anhydride (Styrene), Allyl Propionate and Methyl Methacrylate

&lt;p&gt;The radical terpolymerization reactions of the acceptor-donor-acceptor and donor-acceptor-donor systems, maleic anhydride (MA)-allyl propionate (AP)-methyl methacrylate (MMA) and styrene (St)-MMA-AP, had been studied. The terpolymerizations were carried out in methyl ethyl ketone at 60-75 °C in the presence of 2,2’-azoisobutyronitrile (ABIN) used as the initiator. Some kinetic parameters and copolymerization constants - for both, system were determined by dilatometric and Kelen-Tudos or Seiner-Lift methods. The obtained results are discussed in terms of the free monomer and complex chain growth models. It is shown that terpolymerization was carried out at a stage close to binary copolymerization of MA...AP complex with free MMA and St...MMA complex with AP in the both studied system, respectively. These systems are also used as model for interpretation of cyclocopolymerization mechanism in allyl methactylate-MA (or St) system. DTA and TGA analyses indicated the relatively high thermal stability of St-MMA-AP terpolymer. It is shown that this terpolymer decomposes through a one-step reaction at 310 °C, however MA-AP-MMA terpolymer decomposes through a multi-step reactions at 150, 260 and 310 °C.&lt;/p&gt;