Tetrahydrofurfuryl Methacrylate Research Articles

Evaluation of various monofunctional monomers for the development of fracture tough dental materials exhibiting a low crosslink density

3D printing of fracture tough dental materials that additionally exhibit excellent mechanical properties is challenging. Nowadays, most of the 3D printing dental materials contain a mixture of highly reactive dimethacrylates. The corresponding printed materials exhibit a high crosslink density and are particularly brittle. They are therefore not suitable for additive manufacturing of fracture tough denture bases. Recently, an efficient technology based on the combination of a urethane dimethacrylate macromonomer with a monofunctional monomer and a poly(ɛ-caprolactone)-polydimethylsiloxane-poly(ɛ-caprolactone) triblock copolymer was developed. Materials exhibiting a low crosslink density, excellent mechanical properties, and high fracture toughness were obtained. In this article, further developments of this highly efficient technology are described. A wide range of monofunctional monomers (both methacrylates and acrylates) was evaluated in this system. It was shown that the structure of the selected monofunctional monomer has a strong influence on the mechanical properties (flexural strength and modulus) as well as on the fracture toughness of the light cured materials. Thanks to the formation of nanostructures, a strong increase of fracture toughness was obtained upon addition of the toughening agent (poly(ɛ-caprolactone)-polydimethylsiloxane-poly(ɛ-caprolactone) triblock copolymer). The most promising materials were the ones based on the following monofunctional monomers: 2-phenoxyethyl methacrylate, (octahydro-4,7-methano-1H-indenyl)methyl acrylate, isobornyl acrylate, tetrahydrofurfuryl methacrylate and 4-tert-butylcyclohexyl acrylate. Indeed, these materials exhibited excellent mechanical properties (90.0 ± 3.8 MPa < flexural strength < 102.6 ± 4.7 MPa; 2402 ± 90 MPa < flexural modulus < 2714 ± 68 MPa) combined with high fracture toughness (1.89 ± 0.06 MPa m1/2 ≤ maximum stress intensity factor (Kmax) ≤ 2.18 ± 0.08 MPa m1/2; 418 ± 14 J m−2 ≤ work of fracture (Wf) ≤ 591 ± 25 J m−2). The measured Kmax and Wf were even significantly higher than the values reported for Probase Hot (Kmax = 1.44 ± 0.18 MPa m1/2; Wf = 270 ± 30 J m−2), a clinically proven and well-established PMMA based denture base material from Ivoclar. The successful DLP 3D printing of a monoblock denture using the most promising formulation confirmed the great potential of this technology for the development of 3D printing fracture tough denture bases.

Biobased vitrimer synthesized from 2-hydroxy-3-phenoxypropyl acrylate, tetrahydrofurfuryl methacrylate and acrylated epoxidized soybean oil for digital light processing 3D printing

The development of sustainable biobased vitrimeric materials is critical for the environment. Herein, UV-curable resins composed of the monomers derived from glycerol, soybean oil, and hemicellulose have been designed and applied in digital light processing (DLP) 3D printing. The use of hemicellulose-derived monomer tetrahydrofurfuryl methacrylate for resins can increase the tensile strength that is used to calculate the reprocessability efficiency. The vitrimeric properties of the resulting polymers such as shape memory, weldability, repairability, and reprocessability have been investigated. The most suitable resin for DLP 3D printing containing a sufficient amount of hydroxyl and ester groups that are essential in transesterification reactions has been selected according to the results of the real-time Fourier transform infrared spectroscopy and real-time photorheometry measurements. By activating dynamic transesterification reactions at elevated temperatures, the 3D printed samples exhibited shape memory, repairability, and reprocessability properties. A recovery ratio of 100 %, repairability with improved tensile strength by 2 times, and a recycling efficiency of 344 % was reached by incorporating tetrahydrofurfuryl methacrylate into the resins. The recycling efficiency achieved is 10 times higher compared to a similar vitrimer based on glycerol and soybean oil.

Development and Digital Light Processing 3D Printing of a Vitrimer Composed of Glycerol 1,3-Diglycerolate Diacrylate and Tetrahydrofurfuryl Methacrylate.

The development of biobased reshapable and repairable vitrimers has received extensive attention due to the growing focus on an environmentally friendly society. Therefore, the objective of this research was to synthesize sustainable polymers with an environmentally friendly strategy combining the benefits of renewable resources, UV curing, and vitrimers. Two biobased monomers, glycerol 1,3-diglycerolate diacrylate and tetrahydrofurfuryl methacrylate, were chosen for the preparation of UV-curable resins and tested by real-time photorheometry and RT-FTIR spectroscopy to determine their suitability for digital light processing (DLP) 3D printing. DLP 3D-printed polymer showed shape memory, weldability, and repairability capabilities by triggering the dynamic transesterification process at high temperatures. The vitrimer with a weight ratio of 60:40 of glycerol 1,3-diglycerolate diacrylate and tetrahydrofurfuryl methacrylate showed shape memory properties with a recovery ratio of 100% and a 7-fold improved tensile strength compared to the original sample, confirming efficient weldability and repairability.

Tough and strong sustainable thermoplastic elastomers nanocomposite with self-assembly of SI-ATRP modified cellulose nanofibers

The ingenious design of sustainable thermoplastic elastomers (STPEs) is of great significance for the goal of the sustainable development. However, the preparation of STPEs with good mechanical performance is still complicated and challenging. Herein, to achieve a simple preparation of STPEs with strong mechanical properties, two biobased monomers (tetrahydrofurfuryl methacrylate (THFMA) and lauryl methacrylate (LMA)) were copolymerized into poly (THFMA-co-LMA) (PTL) and grafted onto TEMPO oxidized cellulose nanofiber (TOCN) via one-pot surface-initiated atom transfer radical polymerization (SI ATRP). The grafting modified TOCN could be self-assembled into nano-enhanced phases in STPEs, which are conducive to the double enhancement of the strength and toughness of the STPEs, and the size of nano-enhanced phases is mainly affected by TOCN fiber length and molecular weight of grafting chains. Especially, with the addition of 7 wt% TOCN, tensile strength, tensile strain, toughness, and glass transition temperature (Tg) of TOCN based STPEs (TOCN@PTL) exhibited 140 %, 36 %, 215 %, and 6.8 °C increase respectively, which confirmed the leading level in the field of bio-based elastomers. In general, this work constitutes a proof for the chemical modification and self-assembly behavior of TOCN by one-pot SI ATRP, and provides an alternative strategy for the preparation of high-performance STPEs.

Thin-film composite mixed-matrix membrane with irregular micron-sized UTSA-16 for outstanding gas separation performance

Low-cost, micron-sized particles still pose a barrier to their use in thin-film composite mixed-matrix membranes (TFC-MMMs) owing to their poor interfacial contact with the polymer matrix. Also, the particles are too large to be fabricated into the submicron-thick membranes. Herein, we report high-performing, TFC-MMMs based on a CO2-philic comb copolymer, poly (tetrahydrofurfuryl methacrylate)–co–poly (poly (oxyethylene methacrylate)) (PTO), and an irregular, micron-sized, CO2-selective metal-organic framework (MOF), UTSA-16. The PTO comb copolymer matrix exhibited excellent film-forming ability, adhesion properties and showed a good gas separating performance. The PTO comb copolymer also enhanced the dispersibility of UTSA-16 in an environment-friendly solvent mixture (i.e., ethanol/water), which did not adversely damage the underlying porous polymeric support. Despite the micron-scale particle size of UTSA-16, PTO copolymer completely covered the surface of UTSA-16 via strong interactions without any deep pore infiltration and exhibited excellent interfacial contact properties. Consequently, defect-free TFC-MMMs with a polymer thickness of 300 nm were successfully prepared on the porous support. The TFC-MMM with 10% filler loading exhibited excellent CO2 permeance and selectivity, i.e., CO2 permeance of 1070 GPU, CO2/N2 selectivity of 41.0, CO2/CH4 selectivity of 17.2, outperforming the TFC-MMMs prepared with commercially available Pebax. All PTO-based MMMs, with the exception of the low content of UTSA-16 (5%), exceeded the gas separation performance required for post-combustion CO2 capture process.

Preparation and identification of green polymers towards the production of sustainable latex from β-myrcene and some methacrylate monomers

Sustainable polymers have enough potential to overcome petroleum materials and not completely rely on them for the presence of renewable raw materials, as well as the possibility of developing polymerization methods for renewable raw materials to have these materials recyclability, biodegradability and being a non-toxic material. This has been the focus of recent years. Solvent-free emulsion copolymerization of β-myrcene, a naturally occurring monoterpene monomer, the co-monomers that were used with β-myrcene, tetrahydrofurfuryl methacrylate, iso-bornyl methacrylate, and tert-butyl methacrylate, and each methacrylate monomer was polymerized separately with β-myrcene monomer, β-myrcene –methacrylate monomer (MY/MA) copolymers of different compositions were synthesized under nitrogen atmosphere at 60 ºC, using copolymers composition 50/50 comonomer reactivity ratios, and has been added sodium dodecyl sulfate as emulsifier, and ammonium persulfate as initiator. 1H-NMR, 13CNMR and FTIR spectroscopy were used to confirm the chemical structure and composition. It was found that the copolymerization reaction of each copolymer is influenced with the form of the methacrylate(s) side chain. Furthermore, the thermal properties of copolymers were characterized by DSC and TGA, where the value Tg indicate that random composition copolymers, due to the difference in crystallization of each side chain.

Morphology Control via RAFT Emulsion Polymerization-Induced Self-Assembly: Systematic Investigation of Core-Forming Blocks.

Polymerization-induced self-assembly (PISA) is a useful formulation for readily obtaining nanoparticles from block copolymers in situ. Reversible addition–fragmentation chain-transfer (RAFT) emulsion polymerization is utilized as one of the PISA formulations. Various factors have so far been investigated for obtaining nonspherical particles via RAFT emulsion polymerization, such as the steric structure of the shell, the glass-transition temperature (Tg) of the core-forming block, and the water solubility of the core-forming monomer. This study focuses on core-forming blocks without changing the structure of the shell-forming block. In particular, we elucidate the balance between Tg for the core-forming block and the water solubility of the core monomer. A series of alkyl methacrylates, such as methyl methacrylate (MMA), ethyl methacrylate (EMA), and n-propyl methacrylate (PrMA), are emulsion-polymerized in the presence of a poly[poly(ethylene glycol) methyl ether methacrylate] (PPEGMA) macromolecular chain-transfer agent via the RAFT process. The resulting in situ morphology changes to form shapes such as spheres, worms (toroids), and vesicles are systematically investigated. The properties of the core that determine whether a morphological change occurs from spheres are (i) the solubility of the core-forming monomer in water, (ii) the relationship between Tg for the core-forming block and the polymerization temperature, and (iii) the hydrophobic core volume, which changes the packing parameter. These factors allow prediction of the block copolymer morphology produced during RAFT emulsion polymerization of other methacrylates such as n-butyl methacrylate (BuMA), tetrahydrofurfuryl methacrylate (THFMA) with physical properties of the homopolymer (poly(tetrahydrofurfuryl methacrylate) (PTHFMA)) between those for poly(MMA) (PMMA) and PBuMA, and 1-adamantyl methacrylate (ADMA) with low monomer solubility in water and high Tg of the homopolymer (PADMA).

Characteristics of experimental resin-modified glass-ionomer cements, containing alternate monomers to HEMA

ObjectiveResin-modified glass ionomer cements (RMGICs) present several advantages (e.g. fluoride release), but their reported cytotoxicity has been associated with hydroxyethyl methacrylate (HEMA) monomer release. Therefore, different monomers were tested for use in RMGICs in order to improve their biocompatibility and reduce monomer release. MethodsEight experimental liquid compositions were prepared replacing different percentages of HEMA (conventional monomer used in commercial RMGICs) with hydroxypropyl-methacrylate (HPM) and/or tetrahydrofurfuryl-methacrylate (THFM), which are known to have better biocompatibility. Moreover, two commercial materials (Fuji-Plus and RelyX) and two compositions, based on these (home), were included as controls. Monomer release of all materials (commercial, home and experimental) were tested using high-performance liquid chromatography (HPLC) methods after immersing discs in deionized-water (DW) or ethanol:DW. Cytotoxicity of the materials extracts was tested on normal human oral fibroblast line (NHOF-1) using 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) assay. ResultsThree experimental materials containing THFM (F3, R3 and R4) showed less or similar monomer release compared to corresponding commercial products. Furthermore, two experimental materials (F3 and F4) showed similar effects on NHOF-1 cells compared to the negative control medium. SignificanceThe lower monomer release and higher cell viability of some experimental THFM compositions are encouraging. THFM partially replacing HEMA is potentially a suitable alternative for producing biocompatible RMGICs.

Photothermal and magnetocaloric-stimulated shape memory and self-healing via magnetic polymeric composite with dynamic crosslinking

Multiple-stimulated shape-memory and self-healing materials can be employed in some covert circumstances and special system because of the flexible control manners, which shows great potential in practical application. In this work, Fe3O4 grafted copolymer, Fe3O4-g-P(TMA-co-LA-co-VI), with magnetic, near-infrared light and thermo multiple-stimulated shape memory and self-healing performance, was synthesized, where tetrahydrofurfuryl methacrylate (TMA), lauryl acrylate (LA) and 1-vinylimidazole (VI) were biomass derived monomers. Dynamic metal-ligand network in Fe3O4-g-P(TMA-co-LA-co-VI)/Zn was subsequently constructed via the coordination of VI and zinc ion. The mechanical properties of the nanocomposite could be simply regulated by varying the Fe3O4 content and the molar ratio of monomers. Among all the samples, Fe3O4-g-P(TMA-co-LA-co-VI)/Zn with Fe3O4 content of 1 wt % and TMA/LA/VI molar ratio of 8/2/2.5 showed a breaking stain of 300% and a maximum stress of 1.66 MPa, which also showed an excellent thermo stimulated shape memory and self-healing performance. As the Fe3O4 nanoparticles were uniformly dispersed in the nanocomposites, their photothermal and magnetocaloric transformation can efficiently stimulate the dynamic and reversible metal-ligand crosslinked process between VI and Zn2+. Therefore, this kind of effective stimulation can finally lead to excellent remote-controllable shape memory and self-healing performance. The integration of magnetic, near-infrared light and thermo multiple-stimulation for shape memory and self-healing also augurs well for their wide application potential in artificial intelligence materials and life science.

Elution behavior of a 3D-printed, milled and conventional resin-based occlusal splint material

ObjectiveThe elution of unpolymerized (co-)monomers and additives from methacrylic resin-based materials like polymethyl methacrylate (PMMA) can cause adverse side effects, such as mutagenicity, teratogenicity, genotoxicity, cytotoxicity and estrogenic activity.The aim of this study was to quantify the release and the cytotoxicity of residual (co-)monomers and additives from PMMA-based splint materials under consideration of real splint sizes. Three different materials used for additive (3D printing), subtractive (milling) and conventional (powder and liquid) manufacturing were examined. MethodsThe splint materials SHERAprint-ortho plus (additive), SHERAeco-disc PM20 (subtractive) and SHERAORTHOMER (conventional) were analysed. 16 (n = 4) sample discs of each material (6 mm diameter and 2 mm height) were polished on the circular and one cross-section area and then eluted in both distilled water and methanol. The discs were incubated at 37 °C for 24 h or 72 h and subsequently analysed by gas chromatography/mass spectrometry (GC/MS) for specifying and quantifying released compounds. XTT-based cell viability assays with human gingival fibroblasts (HGFs) were performed for Tetrahydrofurfuryl methacrylate (THFMA), 1,4-Butylene glycol dimethacrylate (BDDMA) and Tripropylenglycol diacrylate (TPGDA). In order to project the disc size to actual splint sizes in a worst-case scenario, lower and upper jaw occlusal splints were designed and volumes and surfaces were measured. ResultsFor SHERAeco-disc PM20 and for SHERAORTHOMER no elution was determined in water. SHERAprint-ortho plus eluted the highest THFMA concentration of 7.47 μmol/l ±2,77 μmol/l after 72 h in water. Six (co-)monomers and five additives were detected in the methanol eluates of all three materials tested. The XTT-based cell viability assays resulted in a EC50 of 3006 ± 408 μmol/l for THFMA, 2569.5 ± 308 μmol/l for BDDMA and 596.7 ± 88 μmol/l for TPGDA. SignificanceWith the solvent methanol, released components from the investigated splint materials exceeded cytotoxic concentrations in HGFs calculated for a worst-case scenario in splint size. In the water eluates only the methacrylate THFMA could be determined from SHERAprint-ortho plus in concentrations below cytotoxic levels in HGFs.

Carbon Nanotubes-Coated Conductive Elastomer: Electrical and Near Infrared Light Dual-Stimulated Shape Memory, Self-Healing, and Wearable Sensing

Conductive elastomeric composites exhibit a great research potential in the intelligent materials and devices owing to their excellent mechanical and electrical properties. Herein, we reported a carbon nanotube (CNT)-coated conductive elastomer with electrical and near-infrared (NIR) light dual-stimulated shape memory and self-healing performance, which can also utilized in wearable sensing. The conductive elastomer composite, CNT-coated polymer substrate with shape memory and self-healing capacity (CNTs/CHSMPs), was first fabricated by graft copolymerization of tetrahydrofurfuryl methacrylate, lauryl acrylate (LA), and vinylimidazole on CNTs, subsequent supramolecular crosslinking, and CNT coating. Taking advantage of the remote controllability of NIR light and the rapid photothermal conversion by CNTs, the prepared composite can achieve accurate shape memory at a fixed point, and the shape recovery procedure can be completed within 30 s. The integrated conductive network throughout the polymer composite also endowed the material with unique electrical stimulated shape memory recovery performance, derived from the excellent electrothermal transition by CNTs. In addition, CNTs/CHSMPs also displayed self-healing characteristics for prolonging the service life of materials and strain sensitivity properties for the sensing of human motion, which contribute to their prodigious application potential in the field of wearable flexible electronic materials.

High biorenewable content acrylate photocurable resins for DLP 3D printing

AbstractGreen chemistry and green engineering concepts have been combined to develop novel sustainable polymeric materials. Solvent free photocurable acrylate resins with biorenewable carbon content of 75%–82% suitable for application in DLP 3D printing technology were composed by commercially available bio‐based materials, acrylated epoxidized soybean oil (AESO), isobornyl methacrylate (IBOMA), methacrylic ester (ME), tetrahydrofurfuryl acrylate (THFA), and tetrahydrofurfuryl methacrylate (THFMA). They demonstrated high printing accuracy and good adhesion between layers. The monitoring of photocross‐linking kinetics of high biorenewable content acrylate photoresins by the real‐time photorheometry and analysis of their rheological parameters was carried out. Synthesized polymers exhibited high yield of insoluble fraction and thermal decomposition temperature at the weight loss of 10% above 300°C. Polymers AESO/IBOMA and AESO/THFMA showed the highest values of tensile modulus and tensile strength. Biodegradability of the synthesized polymers AESO/ME, AESO/THFA, and AESO/THFMA was investigated by measuring oxygen consumption in a closed respirometer. Such AESO‐based polymers can be a competitive solution to replace petroleum‐derived polymeric materials in additive manufacturing and reduce the environmental impact.

Stability of oxygen-rich plasma-polymerized coatings in aqueous environment.

In this work, we report on the stability of oxygen-rich plasma-polymerized (pp) films in an aqueous environment. The pp films were deposited via atmospheric-pressure plasma jet treatment of polymerizable organic liquids. The monomers used for the plasma-assisted polymerization were tetrahydrofurfuryl methacrylate, 1,2,4-trivinylcyclohexane, and mixtures thereof. The pp films were deposited at different plasma input powers ranging from 3 to 7 W. The stability of the obtained pp films was studied upon long-time storage in pure water and in buffer solutions of pHs 4, 7, and 10. After 24 h of storage of the pp films in de-ionized water, all of the studied pp films experienced thickness losses along with the formation of various ringlike structures at their surface, whereas Fourier transformed infrared (FT-IR) analysis showed no changes in their chemical composition. The pp films stored in pH 10 were completely delaminated from the substrate surface, while the pp films stored for 24 h in pH 4 showed swelling behavior, partial delamination, and the formation of wrinkles at the coatings' surface. The pp films stored for 24 h in pH 7 experienced minor thickness losses and formation of wrinkles at their surface. FT-IR analysis of the pp films stored in buffer solutions of pH 4 and pH 7 showed a decrease of C=O and an increase of O-H stretching signals in all of the cases. The observed chemical changes corresponded to the hydrolysis of esters presented in the pp films' structure.

Effects of the methacrylate monomers with different end groups on the morphologies, electro-optical and mechanical properties of polymer dispersed liquid crystals composite films

ABSTRACT In this work, the effects of the methacrylate monomers with various end groups (methyl, hydroxyl, epoxy, tetrahydrofuran, cyclohexane, benzene and siloxane) on the morphologies, electro-optical and mechanical properties of polymer dispersed liquid crystal (PDLC) composite films were systematically investigated. The polymer network morphologies of the samples prepared with the monomers butyl methacrylate, tetrahydrofurfuryl methacrylate, cyclohexyl methacrylate or benzyl methacrylate were observed, and interestingly the polymer balls and polymer ball-networks morphologies were formed by introducing the hydroxypropyl methacrylate and glycidyl methacrylate, respectively. Meanwhile, the films obtained the optimal electro-optical properties with low driving voltage (10.7 V), fast response time (5.0 ms). Finally, the largest shearing force of the prepared PDLC composite films was two to three times better than that of the pristine sample with 3-(trimethoxysilyl)propyl methacrylate (TPMA) monomer doping or surface treatment methods. Thus, this work offers a new way to optimise the overall performance of PDLC films for practical applications.

Effects of rigid structures containing (meth)acrylate monomers and crosslinking agents with different chain length on the morphology and electro-optical properties of polymer-dispersed liquid crystal films

ABSTRACTThis contribution investigates the preparation of polymer-dispersed liquid crystal (PDLC) films based on meth(acrylate) monomers containing rigid structures. The current study specifically focuses on comparison of the monomers on the basis of meth(acrylate) side group, flexible/rigid structures and rigidity. We find that methacrylate monomers exhibit more preferable electro-optic properties than that of the acrylate monomers. Furthermore, through the systematic variation of rigidity, composition of the monomers and chain length of crosslinking agents, both the morphologies and electro-optic properties of these films are found to be adjustable. A composite film is demonstrated by employing moderately rigid monomer (tetrahydrofurfuryl methacrylate) with low driving voltage (21.0 V) and high contrast ratio (87.5). Therefore, the studies here provide a new approach to optimize the electro-optical properties of the PDLC films by introducing monomers with rigid structures.

Simultaneous Determination of Six Alkaloids in Rat Plasma with On-line SPE–HPLC Using a Homemade Four-Hydrogen Furfuryl-Based Polymer Monolithic Sorbent

A four-hydrogen furfuryl-based polymer monolithic column for solid-phase extraction was prepared via in situ radical polymerization, using tetrahydrofurfuryl methacrylate as the monomer. The monolith was characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy and nitrogen adsorption–desorption method, showing relatively uniform porous structure with micro-, meso- and macro-pores and a relatively high surface area of 54.99 m2 g−1. Online solid-phase extraction–high-performance liquid chromatography was carried out to quantitatively analyze six alkaloids, including caffeine, hydroxy-α-sanshool, hydroxy-β-sanshool, hydroxy-γ-sanshool, hydroxy-γ-isosanshool and γ-sanshool in rat plasma. The results show that the prepared polymer monolithic sorbent exhibits good clean-up ability for bio-matrix, as well as good extractive ability for the six concerning alkaloids in rat plasma. Method validation shows that the correlation coefficients of the linear regressions are higher than 0.998 and the accuracy represented by spiked recovery ranges in 94.37–100.7%, 99.52–101.1%, 98.93–100.8%, 98.36–101.6%, 99.22–101.2% and 99.86–101.4% for the six alkaloids, respectively, as well as the LOD ranges in 2.10–3.90 ng mL−1 and the LOQ in 6.35–10.14 ng mL−1. Compared to the reference works, the present work is a simple and effective method for online extraction and simultaneous determination of six alkaloids in plasma with high accuracy and low cost.

Simple quantitative analytical methods for the determination of alkaloids from medicinal and edible plant foods using a homemade chromatographic monolithic column

A polymer-based chromatographic monolithic column was prepared via in-situ radical polymerization using tetrahydrofurfuryl methacrylate as the monomer. The homemade column was used for the separation and quantitative analysis of alkaloids, including piperine from Piper longum (fruit of Piper longum Linn.) and pepper (fruit of Piper nigrum L.), hydroxy-α-sanshool, and hydroxy-γ-sanshool from zanthoxylum (fruit of Zanthoxylum bungeanum Maxim), as well as caffeine from Wuyi rock tea. The chromatographic fractions were identified by mass spectrometry. Single factor test and orthogonal test were both carried out to optimize the extraction conditions. The method validation indicated that the accuracy represented by spiked recovery ranged in 98.89%–102.06%, the correlation coefficients in 0.99986–0.99999. These results show that the prepared monolithic column can be successfully used to quantitatively analyse alkaloids from the real medicinal and edible plant foods with reversed-phase mechanism, which can avoid the long analytical time using traditional packed C18 column. The present method is a simple, and inexpensive method for quantitatively analysing alkaloids from medicinal and edible plant foods, exhibiting good specificity and durability.

Solvent-free lipase-catalyzed production of (meth)acrylate monomers: Experimental results and kinetic modeling

This paper gives detailed insight in the solventless synthesis of (meth)acrylate esters catalysed by Novozym 435 with a focus on the quantitative understanding of the reaction kinetics. The (meth)acrylate esters were formed from various (heavy boiling) alcohols by applying methyl (meth)acrylate in excess. Attractive ester titers were obtained (up to 800 g.kg−1 for citronellyl acrylate) combined with a depletion of the (heavy boiling) alcohols, simplifying downstream processing. To study the kinetics, all experimentally obtained progress curves were simultaneously used from every conversion as input for nonlinear regression. The generic developed model based on second order reaction kinetics resulted in a good fit with the experimental data. Higher reaction rate constants were systematically obtained for methyl acrylates (from 0.69 kg/mol/h for 2-hexyl-1-decyl acrylate to 1.69 kg/mol/h for citronellyl acrylate) compared to methyl methacrylate (from 0.35 kg/mol/h for tetrahydrofurfuryl methacrylate to 0.44 kg/mol/h for 4-methoxybenzyl methacrylate). This proves the former to be a better accepted substrate for Novozym 435 compared to the latter.

Novel anti-fouling PVDF-g-THFMA copolymer membrane fabricated via photoinduced Cu(II)-mediated reversible deactivation radical polymerization

In this study, we fabricated a novel anti-fouling poly(vinylidene fluoride) (PVDF) membrane using a novel amphiphilic copolymer of PVDF grafted with tetrahydrofurfuryl methacrylate (PVDF-g-THFMA). This copolymer was synthesized via photoinduced Cu(II)-mediated reversible deactivation radical polymerization. The amphiphilic copolymer was characterized by 1H nuclear magnetic resonance and Fourier transform infrared spectroscopy. The morphology of the copolymer was examined using scanning electron microscopy. The permeability and hydrophilicity of the membranes were evaluated on the basis of their pure water flux and dynamic contact angles, respectively. The anti-fouling property of the membranes was evaluated by carrying out filtration using a bovine serum albumin (BSA) solution. The PVDF-g-THFMA copolymer membranes showed a pure flux of up to 293.9 L m−2 h−1 bar−1 and a molecular weight cut off of 39.5 kDa. After the filtration of the BSA solution, the PVDF-g-THFMA copolymer membrane was washed with deionized water and the recovery ratio of the pure water flux reached a value of 89.1%. The modified membrane showed good filtration performance and anti-fouling property.

Fabrication of well‐defined shape memory graft polymers derived from biomass: An insight into the effect of side chain architecture on shape memory properties

ABSTRACTFully sustainable shape memory polymers (SMPs) derived from ethyl cellulose (EC, derived from cellulose), tetrahydrofurfuryl methacrylate (THFMA, derived from furfural), and lauryl methacrylate (LMA, derived from fatty acids) were prepared via “grafting from” atom transfer radical polymer (ATRP). The “grafting from” ATRP strategy allows to fabricate SMPs with EC as a backbone, and LMA and THFMA copolymer as a side chain. By utilizing the one‐pot and sequential monomer addition approach, two types of SMPs with random/semi‐block side chain architectures were obtained, respectively. Random/semi‐block side chain architecture of SMPs was confirmed by DSC, DMA, SAXS, and TEM. The presence of microphase separation in the SMPs with semi‐block side chain architecture provided two distinct thermal transitions, which was needed for triple‐shape memory behavior. Shape memory study showed that SMPs with semi‐block side chain architecture exhibited excellent triple‐shape memory property, and also had higher shape recovery speed and shape recovery ratio than those with random side chain architecture. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 1711–1720