Benzyl Methacrylate Research Articles

Self-assembly of poly(lauryl methacrylate)-b-poly(benzyl methacrylate) nano-objects synthesised by ATRP and their temperature-responsive dispersion properties.

Self-assembling poly(lauryl methacrylate)-b-poly(benzyl methacrylate) (PLMAx-PBzMAy) diblock copolymers were synthesised for the first time using solution atom transfer radical polymerisation (ATRP). The PLMA degree of polymerisation (x) was fixed at 14 and the PBzMA degree of polymerisation (y) was varied from 34 to 74. Post-polymerisation transfer of this new series of diblock copolymers from chloroform into n-dodecane (a poor solvent for PBzMA) resulted in self-assembly of polymeric nano-objects. The morphologies for the latter (spheres, worms and vesicles) were controlled by y. The observed morphologies generally agreed with those reported for related PLMAx-PBzMAy diblock copolymers (x ≥ 16) prepared by polymerisation induced self-assembly (PISA) via reversible addition-fragmentation chain transfer (RAFT) polymerisation (Fielding et al., J. Am. Chem. Soc., 2014, 136, 5790). However, a number of differences were observed such as de-gelation behaviour and the phase boundary positions compared to those expected from Fielding et al. Variable-temperature dynamic light scattering studies for the PLMA14-PBzMA34 spheres revealed that the aggregation number was unaffected by a temperature increase over the range of 20-90 °C, which differed markedly from the behaviour observed for PLMA14-PBzMA64 worms. This difference is a new observation with mechanistic importance for the worm-to-sphere breakdown mechanism. We show that concentrated PLMA14-PBzMAy dispersions (20% w/w) in n-dodecane can be prepared using post-polymerisation transfer. The dispersion with a mixed spherical and worm-like copolymer phase exhibited reversible de-gelation when heated. Surprisingly, the dispersions containing only the worm phase remained as gels (which were white) at temperatures up to 90 °C. Our new ATRP approach for preparing temperature-responsive non-aqueous nano-object dispersions presented here decoupled chain growth and self-assembly and will apply to other copolymer dispersions.

The photo-controlled polymerization-induced self-assembly and reorganization process for fabrication of polymeric nanomaterials

A visible light mediated reversible addition–fragmentation chain transfer (RAFT) dispersion polymerization of benzyl methacrylate (BzMA) is conducted in ethanol using poly(2-dimethylaminoethyl methacrylate) (PDMAEMA) as a macro-chain transfer agent (macro-CTA), affording polymeric nanomaterials with various morphologies.

A Titanium–Organic Framework: Engineering of the Band-Gap Energy for Photocatalytic Property Enhancement

A visible-light-responsive metal–organic framework based on titanium hexameric cluster and high conjugation system of organic linker building block termed MOF-902 was synthesized and fully characterized. The photocatalytic properties of MOF-902 were investigated in the polymerization reaction with various monomers such as methyl methacrylate (MMA), benzyl methacrylate (BMA), and styrene (St), respectively. Gel permeation chromatography (GPC) analysis results demonstrated the high performance of MOF-902 as a catalyst, affording polymer products with high molecular weight (Mn) and low polydispersity index (PDI). The photocatalytic efficiency of MOF-902 in the polymerization transformation obviously exceeds other catalysts such as MOF-901, UiO-66, UiO-66-NH2, MIL-125(Ti), MIL-125-NH2(Ti), and commercial P25-TiO2.

Polymerization-Induced Self-Assembly (PISA) Using ICAR ATRP at Low Catalyst Concentration

Polymerization-induced self-assembly (PISA) was achieved by conducting an initiators for continuous activator regeneration atom transfer radical polymerization (ICAR ATRP) at low ppm of copper catalyst concentration. A poly(oligo(ethylene oxide) methyl ether methacrylate)50 (POEOMA50) macroinitiator and stabilizer was synthesized by an aqueous ICAR ATRP using CuIICl2/tris(pyridin-2-ylmethyl)amine (TPMA) complex. Subsequently, the dispersion polymerization of benzyl methacrylate (BnMA) in ethanol was realized with a CuIIBr2/TPMA complex either at room temperature or at 65 °C using V-70 or AIBN as radical initiators, respectively. The effect of catalyst concentration, radical initiators, targeted degree of polymerization (DP) of PBnMA, solids content, and temperature on the molecular characteristics and self-assembly behavior of block copolymers POEOMA–PBnMA was evaluated by gel permeation chromatography (GPC), transmission electron microscopy (TEM), and dynamic light scattering (DLS). Block copolymers asse...

Leucine‐Based Block Copolymer Nano‐Objects via Polymerization‐Induced Self‐Assembly (PISA)

SummaryPolymerization‐induced self‐assembly (PISA) technique has been used to prepare leucine‐based block copolymer nano‐objects. A side‐chain leucine appending macromolecular chain transfer agent (macroCTA) has been employed for reversible addition‐fragmentation chain transfer (RAFT) mediated dispersion polymerization of benzyl methacrylate (BzMA) in methanol at 65 °C. 1H NMR spectroscopy reveals near quantitative monomer conversions (≥90%) and gel permeation chromatography (GPC) indicated well‐defined block copolymer formation. Morphological evolution has been observed from spherical micelle to fibre to vesicle with increase of the length of the solvophobic block keeping the stabilizer block length and monomer solid content constant.

Interpenetrating photopolymers for intraocular lens application

ABSTRACTInterpenetrating photopolymer network materials suitable for intraocular lens application are presented. A rapidly curable, transparent, hydrophobic material with appropriate optical and thermomechanical properties has been prepared from Benzyl acrylate and Benzyl methacrylate. To improve its biocompatibility and optimize surface—cell interactions, this material was modified with respect to its hydrophobicity. Materials which are more hydrophobic, and more hydrophilic, than the base resin were prepared by copolymerization with either a fluoroacrylate or a PEG acrylate respectively. All materials were characterized for their optical and thermomechanical properties. Their in‐vitro cytotoxicity and interaction with mouse fibroblast cells were also studied. It was shown that all materials of the study were biocompatible and more hydrophilic materials resisted cell attachment and may be more suitable for IOL application than their more hydrophobic counter parts of the study. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44496.

Surface functionalized nano‐objects from oleic acid‐derived stabilizer via non‐polar RAFT dispersion polymerization

ABSTRACTSurface functionalization in a nanoscopic scaffold is highly desirable to afford nano‐particles with diversified features and functions. Herein are reported the surface decoration of dispersed block copolymer nano‐objects. First, side‐chain double bond containing oleic acid based macro chain transfer agent (macroCTA), poly(2‐(methacryloyloxy)ethyl oleate) (PMAEO), was synthesized by reversible addition‐fragmentation chain transfer (RAFT) polymerization and used as a steric stabilizer during the RAFT dispersion block copolymerization of benzyl methacrylate (BzMA) in n‐heptane at 70 °C. We have found that block copolymer morphologies could evolve from spherical micelles, through worm to vesicles, and finally to large compound vesicles with the increase of solvophobic poly(BzMA) block length, keeping solvophilic chain length and total solid content constant. Finally, different thiol compounds having alkyl, carboxyl, hydroxyl, and protected amine functionalities have been ligated onto the PMAEO segment, which is prone to functionalization via its reactive double bond through thiol‐ene radical reactions. Thiol‐ene modification reactions of the as‐synthesized nano‐objects retain their morphologies as visualized by field emission‐scanning electron microscopy. Thus, the facile and modular synthetic approach presented in this study allowed in situ preparation of surface modified block copolymer nano‐objects at very high concentration, where renewable resource derived oleate surface in the nanoparticle was functionalized. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 263–273

ABC Triblock Copolymer Worms: Synthesis, Characterization, and Evaluation as Pickering Emulsifiers for Millimeter-Sized Droplets.

Polymerization-induced self-assembly (PISA) is used to prepare linear poly(glycerol monomethacrylate)–poly(2-hydroxypropyl methacrylate)–poly(benzyl methacrylate) [PGMA–PHPMA–PBzMA] triblock copolymer nano-objects in the form of a concentrated aqueous dispersion via a three-step synthesis based on reversible addition–fragmentation chain transfer (RAFT) polymerization. First, GMA is polymerized via RAFT solution polymerization in ethanol, then HPMA is polymerized via RAFT aqueous solution polymerization, and finally BzMA is polymerized via “seeded” RAFT aqueous emulsion polymerization. For certain block compositions, highly anisotropic worm-like particles are obtained, which are characterized by small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM). The design rules for accessing higher order morphologies (i.e., worms or vesicles) are briefly explored. Surprisingly, vesicular morphologies cannot be accessed by targeting longer PBzMA blocks—instead, only spherical nanoparticles are formed. SAXS is used to rationalize these counterintuitive observations, which are best explained by considering subtle changes in the relative enthalpic incompatibilities between the three blocks during the growth of the PBzMA block. Finally, the PGMA–PHPMA–PBzMA worms are evaluated as Pickering emulsifiers for the stabilization of oil-in-water emulsions. Millimeter-sized oil droplets can be obtained using low-shear homogenization (hand-shaking) in the presence of 20 vol % n-dodecane. In contrast, control experiments performed using PGMA–PHPMA diblock copolymer worms indicate that these more delicate nanostructures do not survive even these mild conditions.

From Macromolecular to Small‐Molecular Triggers: Facile Method toward Photoinduced LCST Phase Behavior of Thermoresponsive Polymers in Mixed Ionic Liquids Containing an Azobenzene Moiety

Instead of the reported photoinduced lower critical solution temperature (LCST) phase transition behavior in ionic liquids (ILs) achieved by photofunctional polymers, this study reports the facile photoinduced LCST phase behavior of nonfunctionalized polymers (poly(benzyl methacrylate) (PBnMA) and poly(2-phenylethyl methacrylate) (PPhEtMA)) in mixed ILs (1,3-dimethylimidazolium bis(trifluoromethanesulfonyl)amide; [C1 mim][NTf2 ] and a newly designed functionalized IL containing an azobenzene moiety (1-butyl-3-(4-phenylazobenzyl)imidazolium bis(trifluoromethanesulfonyl)amide; [Azo][NTf2 ])) as a small-molecular photo trigger. Interestingly, the length of the alkyl spacer between the ester and aryl groups, which is the only structural difference between the two polymers, leads to two different photoresponsive LCST phase transition behaviors. On the basis of spectroscopic studies, the different phase transition behaviors of PBnMA and PPhEtMA may attribute to the different cooperative interactions between the polymers and [C1 mim][NTf2 ].

Refractive index increase of acrylate‐based polymers by adding soluble aromatic guest‐molecules

This work presents the influence of dopants on viscosity in an uncured liquid state as well as on refractive index, Abbe number, optical loss, and glass transition temperature of different polymer compositions. The base material consists of Genomer 2263, a bisphenol, an epoxy diacrylate as matrix polymer, and benzyl methacrylate as comonomer. As dopants, the soluble aromatic guest‐molecules 9‐bromophenantrene and 9‐vinylcarbazole are investigated. The viscosity can be adjusted by different mixtures of the matrix polymer and comonomer from 3000 down to 4 mPa sec. Depending on the type and content of the dopants, the refractive index, Abbe number, and the glass transition temperature can be adjusted. The refractive indices increase linear at 589 nm and 20°C from 1.572 to 1.638 by doping, with Abbe numbers between 20 and 30. At this wavelength, the optical losses were determined to be around 2 dB · cm−1. The glass transition temperature can be tailored between 50 and 98°C. A way to use high amounts of optical dopants is presented, which opens up the way for different shaping technologies like inkjet printing of optical components. Copyright © 2016 John Wiley & Sons, Ltd.

Multi-Bit Non-Volatile Organic Transistor-Based Memory Using Lithium-Ion-Encapsulated Fullerene As a Charge Trapping Layer

Organic field-effect transistor (OFETs) based memory devices have been intensively researched in recent years because of their simple structure using a single transistor, reduced data storage losses, and easy integration in electronic circuits.[1] The memory effect in OFETs is achievable by inserting a charge trapping layer such as a thin film of star-shape poly((4-diphenylamino)benzyl methacrylate) between an active layer and a gate dielectric.[2] Charges can be injected to the charge trapping layer by applying a programming voltage, and will be stored after voltage removal. The stored charges affect on the drain current (I D) of the OFETs, and cause a shift of the threshold voltage (V th), which corresponds to the change of logic state. The stability of each state contributes to the memory effect. Expansion of the storage capacity of OFETs has been the object of many researches.[2,3] Lithium-ion-encapsulated fullerene (Li+@C60) would be a potential material for the charge trapping layer of multi-bit memories, because its three-fold degenerated lowest unoccupied molecular orbital (LUMO) is expected to accept up to 6 electrons by an applied voltage.[4] In this presentation, we demonstrate a multi-bit memory OFETs using Li+@C60 as the charge trapping layer. The top-contact OFETs using heavily doped p-type silicon wafers with a 400-nm-thick silicon dioxide were fabricated (Fig 1a). The layers of bis(trifluoromethylsulfonyl)imide Li+@C60 salt (Li+@C60NTf2 -, Fig. 1b) (island-formed) and Cytop (10 nm) were spin-coated on the silicon dioxide. Subsequently, a 50-nm layer of pentacene and copper electrodes (50 nm) were deposited at the pressure of 2.5 × 10-5 Torr. The length (L) and width (W) of the channel were 50 μm and 2000 μm, respectively. The electrical characteristics of the memory devices were measured with a semiconductor characterization system (Keithley) in a dry nitrogen atmosphere at room temperature. The as prepared OFET memories exhibited a good performance with low threshold voltage (V th) of -5.98 V and high electron mobility (μ) of 0.84 cm2V-1s-1. Then, to bring the transfer curve to the erased state, a negative voltage of -150 V was applied to the gate for 5 s, which results in V th of -19.79 V. For programming, a voltage of 150 V was applied to the gate for 0.5 s. The transfer curve shifted to the positive V G region with a V th of -9.99 V, reflecting a memory window (ΔV th) of approximately 10 V. To erase memory, a negative voltage of -150 V was applied to the gate for 0.17 s. The transfer curve shifted back to the erased state. The memory OFETs were subsequently programmed with a voltage of 150 V for 5 s or 50 s, and then erased with a voltage of -150 V for 1.7 s or 17 s, respectively. The transfer curve shifted to positions with a V th of -3.40 V and 12.40 V, respectively, and was brought back by erasing exactly to the erased state. Estimated values for ΔV th of 16 V and 32 V were clearly observed (Fig 1c). In our memory OFETs, the transfer curve of programmed states can go back to that of erased state. It is clear that the memory OFETs with Li+@C60 operated as multi-bit memories. In addition, to evaluate the long-time operation of the memory OFETs, the retention times of both the programmed and erased states were measured at a V D of -60 V and a V G of 0 V. A clear difference in logic states was observed for more than 3000 sec. (Fig 1d) To clarify the origin of the multi-bit memory effect of memory OFETs with Li+@C60, OFETs without Li+@C60 were also fabricated and compared the memory behaviors. The memory OFETs without Li+@C60 exhibit a 1-bit memory characteristics, which is in line with the results reported by Dao in 2012 [5]. In constrast, the memory OFETs with Li+@C60 exhibited muti-bit characteristics due to the difference in number of trapped electrons at the Li+@C60 layer under different programming conditions. This would result from the high electron acceptability of the three-fold degenerated LUMO of Li+@C60.[4] We therefore conclude that the electron-trapping ability of the Li+@C60 layer is at the origin of the multi-bit effect in our memory OFETs. [1] S.-T. Han et al., Adv. Mater. 25 (2013) 5425 - 5449. [2] Y.-C. Chiu et al., NPG Asia Mater. 5 (2013) e35. [3] K.-J. Baeg et al., Adv. Mater. 22 (2012) 2915 - 2926. [4] Y. Kawashima et al., Chem. Asian J. 10 (2015) 44 - 54. [5] T.T. Dao et al., Org. Electron. 13 (2012) 2709 - 2715. Figure 1

Experimental and theoretical investigation of molecular structure, vibrational analysis, chemical reactivity, electrostatic potential of benzyl methacrylate monomer and homopolymer

Until now, a number of new polymers have been discovered with the aid of experimental and computational molecular approaches and indicated to have potential applications. All the computational molecular approaches provide information helpful to further study. So, monomer and homopolymer of benzyl methacrylate (BzMA), which is a popular methacrylate ester monomer, were synthesized and investigated based on density functional theory (DFT) and Hartree–Fock (HF) methods. The monomer and homopolymer were characterized by FTIR, 1H, and 13C NMR techniques. The molecular geometry, geometrical parameters, Mulliken atomic charges, and vibrational frequencies of BzMA monomer and homopolymer (in dimer form) were calculated by using the DFT and HF methods with 6-31G (d, p) as basis set. The molecular electrostatic potential maps and molecular orbitals properties of monomer and homopolymer were calculated using the 6-31G (d, p) basis set of theories. Besides, 1H and 13C chemical shifts were calculated by the gauge–including atomic orbital approach. The results demonstrated that the theoretical values were in good agreement with the experimental values. The calculated data are important to providing insight into molecular analysis and may be used in technological applications.

Occlusion of Sulfate-Based Diblock Copolymer Nanoparticles within Calcite: Effect of Varying the Surface Density of Anionic Stabilizer Chains.

Polymerization-induced self-assembly (PISA) offers a highly versatile and efficient route to a wide range of organic nanoparticles. In this article, we demonstrate for the first time that poly(ammonium 2-sulfatoethyl methacrylate)-poly(benzyl methacrylate) [PSEM–PBzMA] diblock copolymer nanoparticles can be prepared with either a high or low PSEM stabilizer surface density using either RAFT dispersion polymerization in a 2:1 v/v ethanol/water mixture or RAFT aqueous emulsion polymerization, respectively. We then use these model nanoparticles to gain new insight into a key topic in materials chemistry: the occlusion of organic additives into inorganic crystals. Substantial differences are observed for the extent of occlusion of these two types of anionic nanoparticles into calcite (CaCO3), which serves as a suitable model host crystal. A low PSEM stabilizer surface density leads to uniform nanoparticle occlusion within calcite at up to 7.5% w/w (16% v/v), while minimal occlusion occurs when using nanoparticles with a high PSEM stabilizer surface density. This counter-intuitive observation suggests that an optimum anionic surface density is required for efficient occlusion, which provides a hitherto unexpected design rule for the incorporation of nanoparticles within crystals.

Poly(N-2-(methacryloyloxy)ethyl pyrrolidone)-poly(benzyl methacrylate) diblock copolymer nano-objects via RAFT alcoholic dispersion polymerisation in ethanol

N-2-(methacryloyloxy)ethyl pyrrolidone (NMEP) is a highly polar monomer that is much more readily copolymerised with methacrylic monomers than its structural analogue, N-vinyl pyrrolidone. The RAFT solution polymerisation of NMEP has been conducted in ethanol at 70 °C while varying the degree of polymerisation (DP) from 70 to 400. Reducing the CTA/initiator molar ratio from 10.0 to 3.0 when targeting PNMEP100 led to a three-fold rate enhancement and increased the final monomer conversion from 72% to 98%. Targeting DPs of 200 or greater led to lower monomer conversions. DMF GPC analysis of a series of PNMEPx homopolymers confirmed a linear increase in molecular weight with conversion and relatively low dispersities (Mw/Mn < 1.26). A PNMEP50 macro-CTA was chain-extended with benzyl methacrylate (BzMA) via RAFT alcoholic dispersion polymerisation. High BzMA conversions (>90%) were obtained and electron microscopy studies indicated that a range of diblock copolymer morphologies, e.g. spheres, worms and vesicles, were produced by polymerisation-induced self-assembly (PISA). Finally, a PNMEP47-PBzMA243 diblock copolymer was synthesised via a convenient ‘one-pot’ protocol whereby a PNMEP47 macro-CTA was first prepared at 97% conversion, followed by in situ RAFT dispersion polymerisation of BzMA to produce diblock copolymer nano-objects. TEM analysis of aliquots taken during the diblock copolymer synthesis indicated a gradual evolution in copolymer morphology from spherical micelles after 1 h to a pure vesicle phase after 8 h via intermediate mixed phases (including worms).

Thermal behavior, decomposition mechanism and some physicochemical properties of starch-g-poly(benzyl acrylate) copolymers

TG/FTIR/QMS-coupled method to study the thermal behavior along with the evolution of volatile decomposition products and thus the decomposition mechanism under inert conditions of some starch-g-poly(benzyl acrylate) copolymers was applied. Starch-g-poly(benzyl acrylate) copolymers under K2S2O8-initiated copolymerization process of benzyl acrylate monomer with gelatinized potato starch were prepared. The ATR-FTIR and 13C CP/MAS NMR confirmed the successful formation of grafted polymers with different grafting parameters such as grafting percent (%G) and grafting efficiency (%GE). The evolution of some physicochemical properties such as swelling, moisture resistance and chemical resistance allowed certifying that the copolymers obtained were more resistant toward polar solvents, moisture and acidic medium due to the incorporation of more hydrophobic chains into starch backbone as compared to unmodified potato starch. The TG/FTIR/QMS studies confirmed their similar thermal stability, two stage decomposition process but different and more complex decomposition mechanism under the second decomposition stage as compared to the previously presented starch-g-poly(benzyl methacrylate) copolymers.

Facile Synthesis of Worm-like Micelles by Visible Light Mediated Dispersion Polymerization Using Photoredox Catalyst.

Presented herein is a protocol for the facile synthesis of worm-like micelles by visible light mediated dispersion polymerization. This approach begins with the synthesis of a hydrophilic poly(oligo(ethylene glycol) methyl ether methacrylate) (POEGMA) homopolymer using reversible addition-fragmentation chain-transfer (RAFT) polymerization. Under mild visible light irradiation (λ = 460 nm, 0.7 mW/cm(2)), this macro-chain transfer agent (macro-CTA) in the presence of a ruthenium based photoredox catalyst, Ru(bpy)3Cl2 can be chain extended with a second monomer to form a well-defined block copolymer in a process known as Photoinduced Electron Transfer RAFT (PET-RAFT). When PET-RAFT is used to chain extend POEGMA with benzyl methacrylate (BzMA) in ethanol (EtOH), polymeric nanoparticles with different morphologies are formed in situ according to a polymerization-induced self-assembly (PISA) mechanism. Self-assembly into nanoparticles presenting POEGMA chains at the corona and poly(benzyl methacrylate) (PBzMA) chains in the core occurs in situ due to the growing insolubility of the PBzMA block in ethanol. Interestingly, the formation of highly pure worm-like micelles can be readily monitored by observing the onset of a highly viscous gel in situ due to nanoparticle entanglements occurring during the polymerization. This process thereby allows for a more reproducible synthesis of worm-like micelles simply by monitoring the solution viscosity during the course of the polymerization. In addition, the light stimulus can be intermittently applied in an ON/OFF manner demonstrating temporal control over the nanoparticle morphology.

Temperature-independent zero-birefringence polymer for liquid crystal displays

A polymer film that shows almost no orientational birefringence even when the polymer main chain is in an oriented state and almost no temperature dependence of orientational birefringence in the temperature range from around −40 to 85 °C was prepared. This temperature range is important because it is where in-car liquid crystal displays (LCDs) are generally used; therefore, it is desirable to have constant orientational birefringence over this range. We suggest a method to compensate for the intrinsic birefringence and temperature coefficient of intrinsic birefringence of individual polymers by copolymerizing monomers of homopolymers that display opposite signs of the two parameters described above. Analysis of four types of polymers, methyl methacrylate (MMA), 2,2,2-trifluoroethyl methacrylate, benzyl methacrylate (BzMA), and phenyl methacrylate (PhMA), reveal that they possess both positive and negative signs of their temperature coefficient of intrinsic birefringence. Using this approach, we prepare P(MMA/PhMA/BzMA) (39:23:38 wt. %), which exhibits almost no intrinsic birefringence and almost no temperature dependence of intrinsic birefringence. The retardation of this polymer film when drawn uniaxially scarcely changed (between 0.3 and 0.8 nm) between 12 and 70 °C, which is small enough not to cause image degradation in LCDs.

Facile Fabrication of Water Dispersible Latex Particles with Homogeneous or Chain-Segregated Surface from RAFT Polymerization Using a Mixture of Two Macromolecular Chain Transfer Agents.

Water dispersible latex particles with randomly mixed shells or chain segregated surface are synthesized from one-pot reversible addition-fragmentation chain transfer heterogeneous polymerization of benzyl methacrylate (BzMA) using a mixture of poly(glycerol monomethacrylate) (PGMA) and poly(2,3-bis(succinyloxy)propyl methacrylate) (PBSPMA) macromolecular chain transfer agents. In methanol, the two in situ synthesized PGMA-b-PBzMA and PBSPMA-b-PBzMA diblock copolymers coaggregate into spherical micelles, which contain PBzMA core and discrete PGMA and PBSPMA nanodomains on the shell. In contrast, in water-methanol mixture (V/V = 9/1), latex particles with homogeneous distribution of PGMA and PBSPMA polymer chains on the shell are obtained. The reasons leading to formation of latex particles with homogenous or chain-segregated surface are discussed, and polymerization kinetics and physical state of PBSPMA in methanol and water-methanol mixtures are ascribed. These polymeric micelles with patterned functional group on the surface are potentially important for application in supracolloidal hierarchical assemblies and catalysis.

Starch-g-poly(benzyl methacrylate) copolymers

The physicochemical properties such as swelling in polar and non-polar solvents, moisture resistance, chemical resistance, ability for gelatinization and the thermal properties along with the evolution of volatile decomposition products of some starch-g-copolymers obtained through the grafting of benzyl methacrylate monomer onto potato starch have been studied. The chemical structure of copolymers was confirmed using ATR–FTIR analysis. The prepared materials were characterized by completely different properties than unmodified potato starch due to the covalent bonding of poly(benzyl methacrylate) chains onto starch backbone. The copolymers were not able to gelate; however, they exhibited higher swelling in non-polar solvents, lower swelling in polar solvents and higher resistance toward moisture, acid and base conditions than unmodified potato starch. In addition, DSC analysis showed that T g of copolymers was shifted to a little higher values as compared to T g of poly(benzyl methacrylate). The thermal stabilities of copolymers and potato starch were comparable. Their decomposition took place in two main stages connected with the emission of various volatile decomposition products (CO2, CO, H2O, CH4, aldehydes, alcohols, furan derivatives, acids, benzyl methacrylate) in inert atmosphere as it was confirmed based on the simultaneous TG/DSC/FTIR analysis.

Hierarchical Sol–Gel Transition Induced by Thermosensitive Self-Assembly of an ABC Triblock Polymer in an Ionic Liquid

We investigated a hierarchical morphology change and accompanying sol–gel transition using a doubly thermosensitive ABC-triblock copolymer in an ionic liquid (IL). The triblock copolymer contains two different lower critical solution temperature (LCST) thermosensitive polymers, poly(benzyl methacrylate) (PBnMA) and poly(2-phenylethyl methacrylate) (PPhEtMA), as the end blocks and poly(methyl methacrylate) (PMMA) as the middle block (PBnMA-b-PMMA-b-PPhEtMA: BMP). BMP undergoes a hierarchical phase transition corresponding to the self-assembly of each of the thermosensitive blocks in the IL, and a sol–gel transition was observed in concentrated, above 10 wt %, polymer solutions. The gelation behavior was affected by polymer concentration, and at 20 wt %, the BMP/IL composite showed a phase transition, with increasing temperature, from solution through a jammed micelle suspension to a physically cross-linked gel. Each phase was formed reversibly and rapidly over the corresponding temperature range. The jamme...