Tert-butyl Acrylate Research Articles

Effect of block ratios on self-assembly morphologies of poly(ε-caprolactone)-block-poly(tert-butyl acrylate) block copolymer

Crystalline-coil block copolymer compositions, determined by block ratios, play a vital role in the construction of different self-assembly morphologies. Here, we synthesized a series of crystalline-coil block copolymers with different block ratios, namely poly (ε-caprolactone)-block-poly (tert-butyl acrylate) (PCL-b-PtBA), to explore the impact of polymer compositions on self-assembly morphologies via crystallization-driven self-assembly (CDSA). It was found that the PCL-b-PtBA can self-assemble into various morphologies including lozenges, quadrilaterals, elongated hexagons, hexagonal platelets, saw blade platelets and spindle micelles. Additionally, transmission electron microscopes (TEM) imaging indicated a gradual morphological transformation from quadrilateral to lozenge platelets, and then to elongated-hexagon platelets with high aspect ratios as the sampling time was prolonged. We hypothesize that variations in polymer composition lead to changes in the self-assembly morphology primarily due to differences in the reduced tethering density of PtBA segments with varying chain lengths, which subsequently impacts the crystallization of PCL. Our work reveals that adjusting block ratios of the PCL-contained block copolymer for self-assembly is a facile way to construct diverse morphologies of polymer materials, and the corresponding materials may have potential applications in fields such as drug delivery, antibacterial treatments and other fields.

Engineering the surface patchiness and topography of polystyrene colloids: From spheres to ellipsoids

HypothesisColloidal surface morphology determines suspension properties and applications. While existing methods are effective at generating specific features on spherical particles, an approach extending this to non-spherical particles is currently missing. Synthesizing un-crosslinked polymer microspheres with controlled chemical patchiness would allow subsequent thermomechanical stretching to translate surface topographical features to ellipsoidal particles. ExperimentsA systematic study using seeded emulsion polymerization to create polystyrene (PS) microspheres with controlled surface patches of poly(tert-butyl acrylate) (PtBA) was performed with different polymerization parameters such as concentration of tBA monomer, co-swelling agent, and initiator. Thermomechanical stretching converted seed spheres to microellipsoids. Acid catalyzed hydrolysis (ACH) was performed to remove the patch domains. Roughness was characterized before and after ACH using atomic force microscopy. FindingsPS spheres with controlled chemical patchiness were synthesized. A balance between two factors, domain coalescence from reduced viscosity and domain growth via monomer absorption, dictates the final PtBA) patch features. ACH mediated removal of patch domains produced either golf ball-like porous particles or multicavity particles, depending on the size of the precursor patches. Patchy microspheres were successfully stretched into microellipsoids while retaining their surface characteristics. Particle roughness is governed by the patch geometry and increases after ACH. Overall, this study provides a facile yet controllable platform for creating colloids with highly adjustable surface patterns.

Hybrid direct ink writing/embedded three-dimensional printing of smart hinge from shape memory polymer

Three-dimensional (3D) printing technology has been widely developed and utilized to make diverse parts from shape memory polymers (SMPs). However, it is still challenging to fabricate functional devices with both complex geometries and embedded circuits using current 3D printing strategies. The objective of this study is to propose a hybrid direct ink writing (DIW)/embedded 3D printing (e-3DP) method, in which direct ink writing is used to print a self-supporting ink into a complex 3D structure at an uncured state while e-3DP is then applied to deposit a conductive ink within the structure. After crosslinking, the device at a cured state with embedded circuits can be formed in one step. This hybrid 3D printing method can only be realized by using ink materials with required rheological properties. Thus, how to develop the self-supporting ink is mainly discussed. Herein, a shape memory photocurable resin, aliphatic urethane diacrylate (AUD), and its chain builder, tert-butyl acrylate (tBA), are selected as the main components of the polymer precursor and fumed silica is used to tune the rheology for printing purposes. It is found that the tBA/AUD ratio affects the rheological properties, dry-out process, filament geometries, and self-supporting capability significantly. For demonstration, a smart hinge with an embedded circuit as strain sensor is successfully printed, which can program and recover its shape by controlling the ambient temperatures, validating the effectiveness of the proposed method for creating functional devices.

Oil absorption stability of modified cellulose porous materials with super compressive strength in the complex environment

AbstractThe occurrence of oil spills has severe damage upon both the environment and human health. Hence, the development of a green, recyclable, complex environment resistant, and efficient oil–water separation aerogel is required in order to effectively absorb marine or industrial oil. In this study, modified cellulose/N,N'-methylenebisacrylamide/tannin (PCMT) composite porous materials were prepared utilizing the sol–gel method and were modified with tertbutyl acrylate. PCMT possesses a three-dimensional interpenetrating porous structure, exhibiting remarkable oil–water separation performance and excellent compressive strength (PCMT can capable of bearing 7000 times its own weight; PCMT can endure 290.3 kPa pressure at 80% strain when the amount of tannin is 0.2 g). The unique pore structure of PCMT engenders differential oil adsorption capacities (PCMT0, PCMT0.05, PCMT0.1, and PCMT0.2 evince higher adsorption capacities for petroleum ether and dichloromethane, n-hexane and dichloromethane, toluene, and toluene and dichloromethane, respectively). Of critical import, PCMT demonstrates exceptional adaptability to complex environments, wherein the porous materials maintain good hydrophobicity and oil absorption capacity under conditions of vigorous stirring, a wide pH range (1–14), a wide temperature range (4–160 °C), ultraviolet irradiation (8 h), and tape peeling (10 times). Moreover, the porous materials may be employed for the recovery of oil through simple mechanical extrusion, thus demonstrating certain economic significance and the application potential in the treatment of oil spills.

Hybrid 3D Printing of Functional Smart Hinges

Smart hinges fabricated using three-dimensional (3D) printing have been accepted in the aerospace, robotics, and biomedical fields since these devices possess a shape memory characteristic. Shape memory polymers (SMPs) are the preferred materials for creating smart hinges due to their ability to achieve programmable complex geometries. However, fabricating SMPs with embedded components remains a challenge due to the constraints of current 3D printing methods and material limitations. This study investigated the use of a hybrid 3D printing method, direct ink writing (DIW), and embedded 3D printing (e-3DP) to print smart hinges with an embedded circuit to act as a strain sensor. The main components of the SMP included tert-Butyl acrylate (tBA) and aliphatic urethane diacrylate (AUD), but this SMP ink had a low viscosity and could not be used for DIW or e-3DP. Fumed silica (FS) was added to the SMP to tune its rheology, and it was shown that the FS concentration significantly affected the rheological properties, dry-out process, filament geometries, and self-supporting capabilities. This study presents a hybrid 3D printing approach for creating smart hinges with internal strain sensors in one step, demonstrating the versatility of DIW/e-3DP. The findings from this work provide a foundational and reliable technical solution to efficiently fabricate functional, self-monitoring, smart devices from SMPs for diverse applications.

Preparation of Polymer-Based Nano-Assembled Particles with Fe3O4 in the Core.

Organic-inorganic nanocomposite particles, possessing defined morphologies, represent the next frontier in advanced materials due to their superior collective performance. In this pursuit of efficient preparation of composite nanoparticles, a series of diblock polymers polystyrene-block-poly(tert-butyl acrylate) (PS-b-PtBA) were initially synthesized using the Living Anionic Polymerization-Induced Self-Assembly (LAP PISA) technique. Subsequently, the tert-butyl group on the tert-butyl acrylate (tBA) monomer unit in the diblock copolymer, yielded from the LAP PISA process, was subjected to hydrolysis using trifluoroacetic acid (CF3COOH), transforming it into carboxyl groups. This resulted in the formation of polystyrene-block-poly(acrylic acid) (PS-b-PAA) nano-self-assembled particles of various morphologies. The pre-hydrolysis diblock copolymer PS-b-PtBA produced nano-self-assembled particles of irregular shapes, whereas post-hydrolysis regular spherical and worm-like nano-self-assembled particles were generated. Utilizing PS-b-PAA nano-self-assembled particles that containing carboxyl groups as polymer templates, Fe3O4 was integrated into the core region of the nano-self-assembled particles. This was achieved based on the complexation between the carboxyl groups on the PAA segments and the metal precursors, facilitating the successful synthesis of organic-inorganic composite nanoparticles with Fe3O4 as the core and PS as the shell. These magnetic nanoparticles hold potential applications as functional fillers in the plastic and rubber sectors.

Asymmetric synthesis of aryl-substituted pyrrolidines by using CFAM ligand-AgOAc chiral system via 1,3-dipolar cycloaddition reaction.

We have prepared a ligand library based on a ferrocenyl aziridinyl methanol core unit (simply called FAM) having a phenyl group, a cyclohexyl group, and a naphthyl group to be used in 1,3-dipolar cycloaddition (1,3-DC) reactions for the synthesis of chiral pyrrolidines. These chiral ligands were used with AgOAc in 1,3-DC reactions taking place between the aryl-substituted azomethine ylides and N-methylmaleimide as the dipolarophile. In each case, the expected aryl-substituted pyrrolidines were obtained in good to excellent yields with acceptable enantioselectivities favoring only the endo product. The chiral catalyst system CFAM4-AgOAc was also used in 1,3-DC reaction with different dipolarophiles such as dimethyl maleate, tert-butyl acrylate, methyl acrylate, trans-chalcone, and vinyl sulfone. In each case, the cycloadducts were obtained in acceptable yields albeit with low ee. Fortunately, it was possible to increase the ee up to >99% upon crystallization.

Catalyst-Free Thia-Michael Addition to α-Trifluoromethylacrylates for 3D Network Synthesis.

Thia-Michael additions (1,4-additions of a thiol to a Michael acceptor) are generally catalyzed by an external Brønsted or Lewis base. A spontaneous (uncatalyzed) Michael addition of thiols to α-trifluoromethyl acrylates is described, as well as its application to the very efficient preparation of a thermoset. A thorough mechanistic investigation, based on an experimental kinetic study and on DFT calculations, is presented for the addition of arene- and alkanethiols to tert-butyl trifluoromethyl acrylate in polar aprotic solvents, unveiling a probable solvent-assisted proton transfer in the rate-determining step and a considerable lowering of the energy barrier induced by the CF3 group.

Impact of the graft’ structure on the behavior of PMMS-based brushes. High pressure studies

In this paper, we have investigated dielectric response at ambient and elevated pressure of poly(mercaptopropyl)methylsiloxane (PMMS) based oligomeric brushes, where the thiol moiety was substituted by various butyl acrylate isomers (n-butyl acrylate (nBA), iso-butyl acrylate (isoBA), tert-butyl acrylate (tertBA)). It was found that the glass transition temperature, Tg, of PMMS is much lower with respect to the other systems despite its ability to form weak hydrogen (H) bonds. What is more, the length scale of cooperativity was the highest in homopolymer and scaled with the steric hindrance of the graft. We also demonstrated that in the examined grafted copolymers, there is one broad relaxation process in dielectric spectra which is wider than that recorded in mechanical response. That probably means that similarly to PMMS, there are two relaxation processes above Tg in grafted copolymers. However, due to similar timescale, they cannot be separated. Further, high-pressure experiments revealed that pressure coefficient of the glass transition temperature, dTg/dp, as well as the activation volume, ΔV, calculated for the segmental process surprisingly does not scale with either the size of monomer nor steric hindrance. This unexpected result must be related to the specific structure adopted by the studied grafted oligomers. Presented herein data expand our understanding on the impact of topology on the dynamics of polymers at ambient and high pressure.

Preparation of functional coating films using breath figure (BF) method and the study of morphological, optical and wettability behavior with varying experimental conditions

In this work, photoactive polymer film coatings were prepared using the breath figure (BF) method, starting from a poly(tert-butyl acrylate-styrene block), PtBA-block-PS and a photochromic agent, 1-(2-hydroxyethyl)-3,3-dimethylindoline-6-nitrobenzopyran (SP) grafted onto the poly(tert-butyl acrylate) block. The effects upon the composite film behavior in response to the solvent concentration, type of solvent and relative humidity were studied. Films containing homogeneously dispersed micrometre-sized pores were obtained. The optical and morphological behavior were investigated using optical microscopy and scanning electron microscopy. The films obtained have various potential applications as surface coating materials with color changing properties, such as whiteboards, device displays or advertising surfaces.

Cobalt(II) and cobalt(III) complexes of tripodal tetradentate diamino-bis(phenolate) ligands: Synthesis, characterization, crystal structures and evaluation in radical polymerization processes

The synthesis and characterization of cobalt(II) (3, 4) and acetato cobalt(III) (5) complexes with two tripodal tetradentate diamino-bis(phenolate) ligands (L1 and L2) are reported. The solid-state structures of proligand H2L1 and complexes 4 and 5 were determined by X-ray crystallography. Complex 4 crystallizes as a dimer via the formation of a Co2O2 core. Complex 5 is monomeric with a six-coordinated cobalt(III) center bearing a chelating acetate ligand. In both structures, the diamino-bis(phenolate) ligand (L1 or L2) is acting as a tetradentate dianionic κ4-(O2,N2) chelating ligand. The diamagnetic nature of complex 5 allowed its characterization by multinuclear NMR spectroscopic techniques. Complex 5 is not a competent unimolecular initiator for the radical polymerization of methyl acrylate or methyl methacrylate. Its cobalt(II) analog (3) did not act as an efficient OMRP moderator for the radical polymerization of activated (styrene, tert-butyl acrylate) and non-activated (vinyl acetate) monomers.

Discovery of a polymer resistant to bacterial biofilm, swarming, and encrustation.

Innovative approaches to prevent catheter-associated urinary tract infections (CAUTIs) are urgently required. Here, we describe the discovery of an acrylate copolymer capable of resisting single- and multispecies bacterial biofilm formation, swarming, encrustation, and host protein deposition, which are major challenges associated with preventing CAUTIs. After screening ~400 acrylate polymers, poly(tert-butyl cyclohexyl acrylate) was selected for its biofilm- and encrustation-resistant properties. When combined with the swarming inhibitory poly(2-hydroxy-3-phenoxypropyl acrylate), the copolymer retained the bioinstructive properties of the respective homopolymers when challenged with Proteus mirabilis, Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli. Urinary tract catheterization causes the release of host proteins that are exploited by pathogens to colonize catheters. After preconditioning the copolymer with urine collected from patients before and after catheterization, reduced host fibrinogen deposition was observed, and resistance to diverse uropathogens was maintained. These data highlight the potential of the copolymer as a urinary catheter coating for preventing CAUTIs.

PCL/Gelatin/Graphene Oxide Electrospun Nanofibers: Effect of Surface Functionalization on In Vitro and Antibacterial Response.

The emergence of resistance to pathogenic bacteria has resulted from the misuse of antibiotics used in wound treatment. Therefore, nanomaterial-based agents can be used to overcome these limitations. In this study, polycaprolactone (PCL)/gelatin/graphene oxide electrospun nanofibers (PGO) are functionalized via plasma treatment with the monomeric groups diallylamine (PGO-M1), acrylic acid (PGO-M2), and tert-butyl acrylate (PGO-M3) to enhance the action against bacteria cells. The surface functionalization influences the morphology, surface wettability, mechanical properties, and thermal stability of PGO nanofibers. PGO-M1 and PGO-M2 exhibit good antibacterial activity against Staphylococcus aureus and Escherichia coli, whereas PGO-M3 tends to reduce their antibacterial properties compared to PGO nanofibers. The highest proportion of dead bacteria cells is found on the surface of hydrophilic PGO-M1, whereas live cells are colonized on the surface of hydrophobic PGO-M3. Likewise, PGO-M1 shows a good interaction with L929, which is confirmed by the high levels of adhesion and proliferation with respect to the control. All the results confirm that surface functionalization can be strategically used as a tool to engineer PGO nanofibers with controlled antibacterial properties for the fabrication of highly versatile devices suitable for different applications (e.g., health, environmental pollution).

Solvent-based recovery of acrylate polymer from display film waste

Acrylate polymer is widely used to manufacture display films as an adhesive. Improper disposal of acrylate polymer-containing display film waste (a kind of E-waste) may cause serious environmental problems. As an effort to develop a display film waste treatment strategy, this study applied a solvent-based method to recover acrylate polymer from display film waste. The solubility of acrylate polymer (e.g. poly( tert-butyl acrylate)) in 18 different organic solvents was calculated using Hansen solubility parameters. As a result, 2-butanol and methyl acetate were chosen as organic solvents for the acrylate polymer recovery from the display film waste. Effects of various recovery parameters (e.g. temperature, time, and stirring speed) on the recovery of acrylate polymer in five different solvent systems consisting of 2-butanol and methyl acetate (2-butanol, methyl acetate, 1:1 mixture, 1:2 mixture, and 2:1 mixture) were explored. 2-Butanol was found to be a better solvent than any others because it is more hydrophobic than methyl acetate. The recovery condition at which the highest acrylate polymer recovery yield in 2-butanol was obtained was T = 30 °C, t = 1 h, and stirring speed of 250 r/min, reaching 8.28 wt%. This study would help to develop an E-waste recycling method that can be recovering value-added products from E-waste.

Fine-Tuning the Degree of Negative Charge and Carboxylate Grafting Density of Polymer-Coated Magnetite Nanoparticle

The surface of magnetite nanoparticle (MNP) was modified with poly(acrylic acid)(PAA)-poly(ethylene glycol) methyl methacrylate (PEGMA) (co)polymer to obtain water dispersible MNP with pH sensitive surfaces via atom transfer radical polymerization (ATRP) of tert-butyl acrylate (t-BA), followed by the t-BA group deprotection. Molar compositions of the (co)polymer were systematically varied, namely 100:0, 75:25, 50:50 and 25:75 of P(t-BA)/PEGMA, respectively, such that the grafting density of carboxylate groups on the MNP surface after the deprotection can be fine-tuned. Transmission electron microscopy (TEM) indicated that the MNP were spherical (ca.5-12 nm in diameter) with some nanoclustering observed. The roles of PAA and PEGMA affecting the hydrodynamic size and zeta potential of the nanocomposites observed via photocorrelation spectroscopy (PCS) were discussed. The percentages of the polymeric composition in the nanocomposites in each step of the reaction were determined via thermogravimetric analysis (TGA) and their magnetic properties were studied via vibrating sample magnetometry (VSM). These novel nanocomposites with pH sensitive surface and magnetically guidable properties might be advantageous for further conjugations either by covalent or ionic bonding with bioentities. HIGHLIGHTS Magnetite nanoparticle (MNP) coated poly(acrylic acid)(PAA)-poly(ethylene glycol) methyl methacrylate (PEGMA) (co)polymer were fabricated via ATRP The ratio of t-BA to PEGMA used in the copolymerization was studied The nanocomposites showed pH sensitive surface and magnetically guidable properties GRAPHICAL ABSTRACT

Phenylboronic acid-modified nanoscale multi-arm polymers for tumor-targeted therapy.

Unimolecular polymer nanomaterials (UPNs) have well-defined structures, desirable stability and designable functional groups, and hence exhibit great application potential in drug delivery. However, the syntheses of UPNs are generally time-consuming and tedious, which greatly limit their applications. In this paper, we present the preparation of a β-cyclodextrin-cored star-shaped polymer with 21 poly(tert-butyl acrylate) arms. This polymer was facilely synthesized by one-step atom transfer radical polymerization (ATRP). After cleaving the tert-butyl ester protecting groups, the abundant carboxylic acid side groups were used to incorporate doxorubicin (DOX), phenylboronic acid (PBA) groups and poly(ethylene glycol) (PEG) to achieve drug loading and tumor drug delivery. Due to the tumor-targeting ability of the PBA groups, this UPN-based nanomedicine showed high tumor accumulation, penetration and therapeutic efficacy.

A Homogenous, Photocrosslinkable Poly(dimethylsiloxane‐co‐methylvinylsiloxane) Solution in an Acrylate Monomer

Front Cover: In article 2200509, Seung Koo Park, Hyung Cheol Shin, and co-workers establish a photocrosslinkable, solvent-free, homogenous poly(dimethylsiloxane) (PDMS) solution in tert-butyl acrylate by calculating 3D distances of solubility parameter ( Δ δ ¯ $\overline {\Delta \delta}$ ) between PDMS and several liquid monomers. PDMS solid materials can be repeatably, continuously obtainable upon UV-irradiation of the solution. The replicas made of PDMS could be mass-produced even with a 3D inkjet printer in various applications.

Ethylene-Vinyl Acetate Copolymers as Potential Thermoplastic Modifiers of Photopolymer Compositions.

The possibility of using thermoplastic polymers in photopolymer compositions for SLA and DLP is discussed in this article. The diffusion and mutual solubility of uncured systems based on tert-butyl acrylate (tBA) and ethylene-vinyl acetate copolymers (EVA) or low-density polyethylene (LDPE) were studied. The solubility and diffusion of tBA with EVA containing 7, 20, and 40 wt.% vinyl acetate (VA) and with LDPE in the temperature range 20-75 °C were studied by optical micro-interferometry method. Phase diagrams of LDPE-tBA, EVA-7-tBA, and EVA-20-tBA systems were obtained. It is shown that the compositions are characterized by the phase-state diagrams of amorphous separation with the upper critical solution temperature (UCST). The concentration dependences of the interdiffusion coefficients as well as dependences of the self-diffusion coefficients on VA content and on temperature were plotted. The activation energy of self-diffusion of EVA and LDPE was calculated. It was shown that the most promising tBA modifier is EVA-40, which is completely soluble at all studied temperature ranges. The obtained data on the mixing of the initial components is valuable for further studies of the processes of structure formation during photocuring of compositions, regulation of the phase structure and, as a consequence, the performance characteristics of the 3D printable materials.

Development and Application of a Poly(acrylic acid)-Grafted Styrene–Butadiene Rubber as a Binder System for Silicon-Graphite Anodes in Li-Ion Batteries

Silicon anodes require polymer binder systems that are both mechanically robust and electrochemically stable, to accommodate the dramatic volume expansion experienced during cycling operation. Herein, we report the use of a poly(acrylic acid)-grafted styrene–butadiene rubber (PAA-g-SBR) with 80% partially neutralized Na-PAA as the binder system for silicon-graphite anodes. The PAA-g-SBR graft copolymer was synthesized by grafting tert-butyl acrylate onto SBR and treating the intermediate with H3PO4. The PAA-g-SBR/Na-PAA binder system was found to provide superior electrochemical performances to that of a Na-PAA/SBR system. The Na-PAA/PAA-g-SBR system had a stable capacity retention of 673 mAh g–1 for 130 cycles, while the capacity retention of the Na-PAA/SBR system was found to decline immediately. The Na-PAA/PAA-g-SBR system also displayed more preferable mechanical properties, with a lower Young’s modulus value and a larger strain at failure compared to that of the Na-PAA/SBR system. Overall, these findings indicate a promising and robust polymer binder system for the application of silicon anodes in the next generation of lithium-ion batteries.

Multicompartment Nanoparticles by Crystallization-Driven Self-Assembly of Star Polymers: Combining High Stability and Loading Capacity.

Herein novel multicompartment nanoparticles (MCNs) that combine high stability and cargo loading capacity are developed. The MCNs are fabricated by crystallization-driven self-assembly (CDSA) of a tailor-made 21 arm star polymer, poly(L-lactide)[poly(tert-butyl acrylate)-block-poly(ethylene glycol)]20 [PLLA(PtBA-b-PEG)20 ]. Platelet-like or spherical MCNs containing a crystalline PLLA core and hydrophobic PtBA subdomains are formed and stabilized by PEG. Hydrophobic cargos, such as Nile Red and chemotherapeutic drug doxorubicin, can be successfully encapsulated into the collapsed PtBA subdomains with loading capacity two orders of magnitude higher than traditional CDSA nanoparticles. Depolarized fluorescence measurements of the Nile Red loaded MCNs suggest that the free volume of the hydrophobic chains in the nanoparticles may be the key for regulating their drug loading capacity. In vitro study of the MCNs suggests excellent cytocompatibility of the blank nanoparticles as well as a dose-dependent cellular uptake and cytotoxicity of the drug-loaded MCNs.