Acryloyl Morpholine Research Articles

Influence of reactive diluent composition on properties and bio-based content of itaconic acid-based additive manufacturing materials

Among the additive manufacturing techniques, UV-curing processes are of special interest, as they allow for the fabrication of thermosetting materials with high resolutions and optical clarity. Traditionally, these processes require the use of formulations, consisting of polyester or polyurethane oligomers, combined with photoinitiators and reactive diluents. The latter are usually vinyl monomers such as acrylates or acrylamides, used to reduce the viscosity of the formulation and render it processable by additive manufacturing machines. In this work, we investigate whether a combination of diluents can be used to tune the thermomechanical properties of the printed materials, and if it can be exploited to increase their overall bio-based content without compromising their performance. To do so, a series of itaconic acid-based polyesters with different chemical structures (aliphatic–aromatic) were synthesized and formulated with reactive diluents acryloyl morpholine (ACMO) and isobornyl acrylate (IBOA). The physicochemical properties of the prepared formulations, together with their reactivity towards UV-light were assessed via photo differential scanning calorimetry (photo-DSC) and photo-rheology measurements. The same formulations were then used to fabricate test specimen via digital light processing (DLP) 3D printing, which were characterized on their thermomechanical properties by means of dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA) measurements. The glass transition temperature of the printed samples reached a maximum of 98 °C, while the diluent ratio could be used to manipulate the Tg in a linear trend. All materials of this study exhibited Td,5% above 250 °C, suggesting good thermal stability. These results show that materials with a very high bio-based content (up to 85%) and very promising thermomechanical properties could be obtained by employing a diluent mixture during the formulation phase.

Preparation and Properties of Temperature Resistant and Salt Resistant Lotion Fracturing Fluid Thickener

In order to prepare fracturing fluid with excellent solubility, temperature resistance, salt resistance and shear resistance, acrylamide (AM), 2-acrylamide-2-methylpropanesulfonic acid (AMPS) and acryloylmorpholine (ACMO) were copolymerized, and anionic cellulose was introduced to synthesize a new type of polyacrylamide copolymer p (AM/AMPS/ACMO) through inverse emulsion polymerization. The structure and morphology were characterized by infrared spectroscopy and scanning electron microscope. The results showed that in 0, 5, 10, 20, 50, 100, 150 and 200 g/L NaCl, CaCl2, and MgCl2 solutions, the viscosity of p (AM/AMPS/ACMO) solution modified by PVA fiber was always higher than that of conventional PAM solution, and the polymer modified by PVA fiber had better salt resistance. The anionic cellulose modified thickener was sheared at 120 ℃ and 150 ℃ for 1 h at 170 s－1, and the viscosity after shearing is 89.92 mPa·s and 80.10 mPa·s, respectively, which is much higher than the viscosity required by the general technical conditions of fracturing fluid more than 50 mPa·s, indicating that anionic cellulose modified p (AM/AMPS/ACMO) has good temperature and shear resistance.

Deriving a point of departure for assessing the skin sensitization risk of wearable device constituents with in vitro methods

Wearable devices are in contact with the skin for extended periods. As such, the device constituents should be evaluated for their skin sensitization potential, and a Point of Departure (PoD) should be derived to conduct a proper risk assessment. Without historical in vivo data, the PoD must be derived with New Approach Methods (NAMs). To accomplish this, regression models trained on LLNA data that use data inputs from OECD-validated in vitro tests were used to derive a predicted EC3 value, the LLNA value used to classify skin sensitization potency, for three adhesive monomers (Isobornyl acrylate (IBOA), N, N- Dimethylacrylamide (NNDMA), and Acryloylmorpholine (ACMO) and one dye (Solvent Orange 60 (SO60)). These chemicals can be used as constituents of wearable devices and have been associated with causing allergic contact dermatitis (ACD). Using kinetic DPRA and KeratinoSens™ data, the PoDs obtained with the regression model were 180, 215, 1535, and 8325 μg/cm2 for IBOA, SO60, ACMO, and NNDMA, respectively. The PoDs derived with the regression model using NAMs data will enable a proper skin sensitization risk assessment without using animals.

Synthesis and plugging effect of inverse emulsion polymerization microspheres (OPME) for oil-based drilling fluids

It is difficult to seal oil-based drilling fluids in the large pore and micro-fracture formation, and there are few suitable materials for the oil phase with good sealing ability at present. In order to solve the problem of the lack of sealing ability of oil-based drilling fluids, acrylamide, 2-acrylamido-2-methylpropane sulfonic acid, and acryloyl morpholine were used as monomers, N'N-methylenebisacrylamide was used as a cross-linking agent, Span-80 and Tween-60 were used as emulsifiers, and 2,2′-azobis(2-methylpropionamidine) dihydrochloride was used as an initiator. Polymer microsphere emulsion OPME was synthesized by inverse emulsion polymerization. The structure of polymer microspheres was characterized by infrared spectroscopy, scanning electron microscopy, electron microscopy, H NMR, laser particle size analysis and thermogravimetric analysis. The optimal synthesis conditions were determined by the control variable method: the monomer ratio of acrylamide, 2-acrylamido-2-methylpropane sulfonic acid, and acryloyl morpholine was 45:20:15, the amount of emulsifier was 8%, and the reaction temperature was 55℃. The synthetic polymer microspheres were added to the oil-based drilling fluids to perform filtration and loss plugging at atmospheric pressure and high-temperature and high-pressure, as well as pore and artificial fracture core plugging evaluation. The evaluation results show that the permeability reduction rate of pore core can reach 82%, and that of fracture core can reach 100% by adding polymer microspheres with 3% dosage. Finally, the pressure transmission experiment proves that the addition of polymer microspheres can slow the pressure transmission and filtrate intrusion, and enhance the stability of wellbore. Therefore, polymer microspheres are a micron-level plugging agent with good compatibility and high performance with oil-based drilling fluids, and the 3% dosage can better seal the formation of large pores and micro-fractures, which has a good potential for field application.

Preparation and evaluation of acryloyl morpholine modified emulsion fracturing fluid thickener with high temperature resistance and salt resistance

AbstractTo prepare the thickener of fracturing fluid with temperature resistance, salt resistance and quick dissolution, an emulsion thickener (ASC) was synthesized by acrylamide, acrylic acid, 2‐acrylamide‐2‐methylpropanesulfonic acid, and acryloyl morpholine. The dissolution, salt resistance and drag reduction of ASC, and the viscoelasticity, temperature resistance and shear resistance and gel breaking properties of fracturing fluid formed by ASC and zirconium crosslinker were investigated. The results showed that the sticky time of ASC was less than 60 s and the drag reduction rate was 72.5% in 100,000 mg/L brine, showing that ASC had thickening ability in high salinity brine and satisfied the requirements of continuous fluid preparation on the fracturing process. The viscosity of ASC fracturing fluid was 98 mPa s after shearing at 200°C and 170 s−1 for 150 min when the salinity was 100,000 mg/L. When the ammonium persulfate concentration was 400 mg/L, the viscosity of the broken fluid was 4.0 mPa s. The temperature resistance, salt resistance and shear resistance of ASC emulsion fracturing fluid could be significantly improved by the introduction of acryloyl morpholine, ASC fracturing fluid had the characteristics of high elasticity and low viscosity, which could meet the application requirements under ultra‐high temperature reservoirs.

Large Scale Vat-Photopolymerization of Investment Casting Master Patterns: The Total Solution.

The material properties and processing of investment casting patterns manufactured using conventional wax injection Molding and those manufactured by vat photopolymerization can be substantially different in terms of thermal expansion and mechanical properties, which can generate problems with dimensional accuracy and stability before and during ceramic shelling and shell failures during the burn-out of the 3D printed casting patterns. In this paper and for the first time, the monofunctional Acryloyl morpholine monomer was used for 3D printing of casting patterns, due to its thermoplastic-like behavior, e.g., softening by heat. However, the hydrophilic behavior of this polymer led to an incorporation of up to 60 wt% of Hexanediol diacrylate, to control the water absorption of the network, which to some extent, compromised the softening feature of Acryloyl morpholine. Addition of a powdered wax filler resulted in a delayed thermal decomposition of the polymer network, however, it helped to reduce the thermal expansion of the parts. The dimensional accuracy and stability of the wax-filled formulation indicated an excellent dimensional tolerance of less than ±130 µm. Finally, the 3D printed patterns successfully went through a burn out process with no damages to the ceramic shell.

Molecular Descriptors as a Facile Tool toward Designing Surface-Functionalized Nanoparticles for Drug Delivery.

Modulating the surface chemistry of nanoparticles, often by grafting hydrophilic polymer brushes (e.g., polyethylene glycol) to prepare nanoformulations that can resist opsonization in a hematic environment and negotiate with the mucus barrier, is a popular strategy toward developing biocompatible and effective nano-drug delivery systems. However, there is a need for tools that can screen multiple surface ligands and cluster them based on both structural similarity and physicochemical attributes. Molecular descriptors offer numerical readouts based on molecular properties and provide a fertile ground for developing quick screening platforms. Thus, a study was conducted with 14 monomers/repeating blocks of polymeric chains, namely, oxazoline, acrylamide, vinylpyrrolidone, glycerol, acryloyl morpholine, dimethyl acrylamide, hydroxypropyl methacrylamide, hydroxyethyl methacrylamide, sialic acid, carboxybetaine acrylamide, carboxybetaine methacrylate, sulfobetaine methacrylate, methacryloyloxyethyl phosphorylcholine, and vinyl-pyridinio propanesulfonate, capable of imparting hydrophilicity to a surface when assembled as polymeric brushes. Employing free, Web-based, and user-friendly platforms, such as SwissADME and ChemMine tools, a series of molecular descriptors and Tanimoto coefficient of molecular pairs were determined, followed by hierarchical clustering analyses. Molecular pairs of oxazoline/dimethyl acrylamide, hydroxypropyl methacrylamide/hydroxyethyl methacrylamide, acrylamide/glycerol, carboxybetaine acrylamide/vinyl-pyridinio propanesulfonate, and sulfobetaine methacrylate/methacryloyloxyethyl phosphorylcholine were clustered together. Similarly, the molecular pair of hydroxypropyl methacrylamide/hydroxyethyl methacrylamide demonstrated a high Tanimoto coefficient of >0.9, whereas the pairs oxazoline/vinylpyrrolidone, acrylamide/dimethyl acrylamide, acryloyl morpholine/dimethyl acrylamide, acryloyl morpholine/hydroxypropyl methacrylamide, acryloyl morpholine/hydroxyethyl methacrylamide, carboxybetaine methacrylate/sulfobetaine methacrylate, and glycerol/hydroxypropyl methacrylamide had a Tanimoto coefficient of >0.8. The analyzed data not only demonstrated the ability of such in silico tools as a facile technique in clustering molecules of interest based on their structure and physicochemical characteristics but also provided vital information on their behavior within biological systems, including the ability to engage an array of possible molecular targets when the monomers are self-assembled on nanoparticulate surfaces.

Evaluation of Reactive Diluent Impact on Stability of Systems Viscosity in UV-Curable Compositions

This study investigated the impact of various reactive diluents on viscosity of uncured mixture at 50 °C over a 12-week period. This criterion is important to predict the shelf life of uncured composition. Studied mono-functional acrylate monomers were: hydroxypropyl methacrylate (HPMA), hydroxyethyl methacrylate (HEMA), tetrahydrofurfuryl acrylate (THFA), isobornyl methacrylate (IBOMA), isobornyl acrylate (IBOA), 2-(2-Ethoxyethoxy)ethyl acrylate (EOEOEA), acryloyl morpholine (ACMO), glacial methacrylic acid (GMAA) and phosphate acrylate monomer (PAM); and various solvents: isopropanol(IP) ethyl acetate (EA), butyl acetate (BA). There was found the difference of effect on the systems viscosity in time between the mono-functional monomers and solvents. HPMA and IPA showed the most stable viscosity values in time.

Fabricating a heavy oil viscosity reducer with weak interaction effect: Synthesis and viscosity reduction mechanism

We synthesized a copolymer with strong hydrophilicity and low surface and interfacial activity, which reduced the viscosity of heavy oil by interacting with asphaltenes or resins via hydrogen bonding. Water-soluble terpolymers (PAMD) were synthesized by the copolymerization of acryloyl morpholine, maleic anhydride with N, N-dimethylacrylamide in pure water. The copolymer showed low surface and interfacial activity, as well as the ability to weakly interact with heavy oil to form oil-in-water emulsions under stirring, but reducing the viscosity of the heavy oil by more than 90%. Under the condition of weak interaction between polymer and heavy oil, the oil-in-water emulsions dehydrated within 1 h to form oil and aqueous phases, which could be reused for the viscosity reduction at least five times. Therefore, this novel heavy oil viscosity reducer to provide a convenient and effective technique for oil extraction and reduce the burden of economic costs.

Fabrication of barium titanate ceramics via digital light processing 3D printing by using high refractive index monomer

A digital light processing (DLP) technology has been developed for 3D printing lead-free barium titanate (BTO) piezoelectric ceramics. By comparing the curing and rheological properties of slurries with different photosensitive monomer, a high refractive index monomer acryloyl morpholine (ACMO) was chosen, and a design and preparation method of BTO slurry with high solid content, low viscosity and high curing ability was proposed. By further selecting the printing parameters, the single-layer exposure time was reduced and the forming efficiency has been greatly improved. Sintered specimens were obtained after a nitrogen-air double-step debinding and furnace sintering process, and the BTO ceramics fabricated with 80 wt% slurry shows the highest relative density (95.32 %) and piezoelectric constant (168.1 pC/N). Furthermore, complex-structured BTO ceramics were prepared, impregnated by epoxy resin and finally assembly made into hydrophones, which has significance for the future design and manufacture of piezoelectric ceramic-based composites that used in functional devices.

Highly stretchable and transparent dielectric gels for high sensitivity tactile sensors

Soft tactile sensors have been widely used in wearable electronics and soft robotics. Among different sensing technologies, soft capacitive sensors receive much attention due to good signal repeatability, temperature insensitivity, relative simplicity of fabrication and adaptability of configuration. Many methods such as adding nano-fillers have been developed to increase the sensitivity of capacitive sensors. However, the existing methods usually sacrifice the transparency and reduces the flexibility. In this work, we propose to use dielectric gels to fabricate capacitive sensors for the first time. We synthesize dielectric gels by using ethylene carbonate and propylene carbonate as solvents and 2-Ethylhexyl acrylate and acryloyl morpholine as polymer networks. The synthesized dielectric gels are extremely soft, highly stretchable, and fully transparent to visible lights. The relative permittivity is as high as 30. We demonstrate that the sensitivity of the capacitive sensor made of the new dielectric gel increases about 6 times compared to the sensors made of VHB, PDMS, or Ecoflex. We design a touch sensor with the dielectric gel to control the LED, and also demonstrate the use of the dielectric gels as the transparent cover layer of a cell phone which may displace the traditional protective layer made of glass in future wearable electronics.

High modulus hydrogels for ophthalmic and related biomedical applications.

This paper presents three families of semi-interpenetrating polymer network (SIPN) hydrogels based on an ester-based polyurethane (EBPU) and hydrophilic monomers: N,N-dimethylacrylamide (NNDMA), N-vinyl pyrrolidone (NVP) and acryloylmorpholine (AMO) as potential materials for keratoprosthesis, orthokeratology and mini-scleral lens application. Hydrogels sheets were synthesized via free-radical polymerization with methods developed in-house. SIPN hydrogels were characterized for their equilibrium water content, mechanical and surface properties. Three families of optically clear SIPN-based hydrogels have been synthesized in the presence of water with >10% of composition attributable to EBPU. Water contents of SIPN materials ranged from 30% to 70%. SIPNs with ≤15% EBPU of total composition showed little influence to mechanical properties, whereas >15% EBPU contributed significantly to an increase in material stiffness. In the hydrated state, SIPNs with ≤15% EBPU of total composition show little difference in polar component (γp ) of surface free energy, whereas for >15% EBPU there is a decrease in γp . The EBPU SIPN hydrogels display complementary material properties for keratoprosthesis, orthokeratology, and mini-scleral applications. © 2018 The Authors. Journal of Biomedical Materials Research Part B: Applied Biomaterials published by Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 1645-1653, 2019.

Functionalization of multiwalled carbon nanotubes by amidation and Michael addition reactions and the effect of the functional chains on the properties of waterborne polyurethane composites

ABSTRACTA new class of hydrophilic multiwalled carbon nanotubes (MWCNTs) was prepared by amidation of carboxylated MWCNTs and then undergoing the Michael addition reactions with hydroxyethyl acrylate (HEA), acryloyl morpholine (ACMO), and acrylamide (AM), respectively. The functionalized MWCNTs were dispersible well in water showing zeta potential value of higher than −33.8 mV. After used as reinforcing filler to fabricate the waterborne polyurethane (WPU) composites, the functionalized MWCNTs showed more homogenous dispersion and stronger interfacial adhesion in/with WPU matrix in comparison with pristine MWCNTs, leading to an effective improvement in the mechanical properties, hydrophilicity and electrical conductivity of the MWCNTs/WPU composites. As fabrication of 1.5 wt % MWCNTs composite, the tensile stress was greatly enhanced by about 20.3, 22.5, and 30.1% from 13.3 MPa of the pristine MWCNTs composites to 16.0, 16.3, and 17.3 MPa for the MWCNTs‐HEA, ‐ACMO, and ‐AM composites, respectively. Varying hydrophilic moieties offered different mechanical properties and electrical conductivities to the MWCNTs/WPU composites, which is suggested to be caused by the improved compatibility and hydrogen bonds between the functionalized MWCNTs and WPU macromolecules. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46757.

New insights in poly(vinylidene fluoride) (PVDF) membrane hemocompatibility: Synergistic effect of PVDF-g-(acryloyl morpholine) and PVDF-g-(poly(acrylic acid)-argatroban) copolymers

Hydrophilic and hemocompatible surface design is vital for poly(vinylidene fluoride) (PVDF) membranes in biological application especially for hemodialysis. In this work, the influence and synergistic effect of PVDF-g-(acryloyl morpholine) (PVDF-g-ACMO) and PVDF-g-(poly(acrylic acid)-argatroban) (PVDF-g-(PAA-AG)) copolymers blending modification on structure and properties of PVDF membrane were investigated. The membranes were prepared through immersion phase transition method. The copolymer structure was characterized by FT-IR and 1H NMR. Modified membrane surfaces obtained were characterized by XPS. The blending modified PVDF hollow fiber membranes were confirmed to have excellent hydrophilicity, good hemocompatibility properties (protein adsorption, platelets/ red blood cells adhesion, plasma coagulation), good permeability and anti-protein fouling performance. The hydrophilic and anti-hemolytic properties were significantly improved with the weight percentage of PVDF-g-ACMO copolymer, and PVDF-g-(PAA-AG) copolymer endow the anti-coagulation of modified membranes. And when the blend ratio was up to 1:3, the blend membranes show the longest clotting time (APTT 114.15 s and PT 25.65 s). This work provides a new modification method to improve the hemocompatibility for PVDF membranes in potential biological applications.

Improved fouling resistance of poly(vinylidene fluoride) membrane modified with poly(acryloyl morpholine)-based amphiphilic copolymer

An amphiphilic copolymer of poly(methyl methacrylate)-co-poly(N-acryloylmorpholine) (PMMA-co-PACMO) was synthesized via radical copolymerization. The copolymer was directly blended with poly(vinylidene fluoride) (PVDF) to prepare flat membranes using the phase inversion technology. During membrane formation, the hydrophilic PACMO chains were preferably segregated onto membrane surface, which endowed the PVDF/PMMA-co-PACMO membranes with the enhanced hydrophilicity. The prepared PVDF/PMMA-co-PACMO membranes showed lower protein adsorption than pristine PVDF membrane, due to the elimination of interaction force between membrane and protein. With the increase of copolymer concentration in the casting solution, the macrovoids were gradually formed at the cross section of the PVDF/PMMA-co-PACMO membranes. Filtration experiments indicated that the total and irreversible membrane fouling ratios were significantly suppressed via the incorporation of PMMA-co-PACMO. The flux recovery ratio of the PVDF/PMMA-co-PACMO membrane was as high as 98.4%. These results suggested that the hydrophilic modification by blending amphiphilic copolymer PMMA-co-PACMO was a feasible approach to improve anti-fouling property of PVDF membrane.

Preparation and thermal stability of initiator fragments end-capped oligomers/silica nanocomposites

A variety of initiator fragments end-capped oligomers [X ∼ (M)n ∼ X; M = N, N-dimethylacrylamide (DMAA), acrylic acid (ACA), N-(1,1-dimethyl-3-oxobutyl)acrylamide (DOBAA), and acryloylmorpholine (ACMO); X = initiator fragments] were synthesized by oligomerization of the corresponding monomers catalyzed by the radical initiators such as ammonium persulfate (APS), 2,2′-azobis(2-methyl-N-(2-hydroxyethyl)propionamide) (VA-086), and azobisisobutyronitrile (AIBN). These initiator fragments end-capped oligomers were found to cause a gelation toward not only water but also traditional organic media such as methanol, 2-propanol, propylene carbonate, 1,2-dichloroethane, and tetrahydrofuran. These obtained oligomers were applied to the nanocomposite reactions with silica nanoparticles in the presence of tetraethoxysilane (TEOS) under alkaline conditions to provide the corresponding oligomers/silica nanocomposites. In these nanocomposites, X ∼ (M)n ∼ X/SiO2 nanocomposites, which were prepared by using APS as an initiator, were found to afford the clear weight loss in proportion to the contents of the oligomers in the composites after calcination at 800 °C. However, interestingly, X ∼ (M)n ∼ X/SiO2 nanocomposites, which were prepared by using VA-086 and AIBN, afforded no weight loss corresponding to the contents of the oligomers in the composites even after calcination at 800 °C.

UV curable bismaleimides films with functionalized colliodal silica

Abstract Four acrylated bismaleimides were formulated with PDMS functionalized silica colloids and UV-cured. The acrylated bismaleimides were synthesized via a two-step procedure. The first step involved the solution imidization of 2,2′-Bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride (BPADA), with 4,4′-oxydianiline (ODA) or Bisaniline M (BIS M), 2,2-Bis(amino-4-hydroxyphenyl)hexafluoropropane (BIS-AP-AF) and maleic anhydride (MA) to form hydroxylated bismaleimide. In the second step, the hydroxylated bismaleimide was reacted with acryloyl chloride to form an acrylated bismaleimide. Then, the acrylated bismaleimide was formulated with acryloyl morpholine (AMP) and photoinitiator with or without the addition of PDMS-silica nanoparticles and UV-cured. The curing kinetics were investigated by real-time FTIR and photo-DSC. The kinetic data revealed that the PDMS-silica particles accelerated the photocure rate. The dispersion of PDMS-silica nanoparticles on the film surface was investigated by SEM. Abrasion properties were evaluated using a Taber Abraser. The optimal abrasion resistance was achieved with 3.0 wt% PDMS-silica loading.

Recovery of Au(III) ions by Au(III)-imprinted hydrogel

AbstractA new Au(III)-imprinted hydrogel (Au(III)-Imp) was prepared by the photopolymerisation of 4- acryloylmorpholine (AcM), 2-hydroxyethyl acrylate (HEA), and poly(ethylene glycol) diacrylate (cross-linking monomer, PEG-DA) in the presence of gold ions. In addition, non-imprinted hydrogel (N-Imp) was similarly prepared without Au(III) ions The Au(III)-Imp hydrogel was characterised by several techniques. To achieve the optimal conditions, effect of pH, time, and initial metal ion concentrations were investigated using a batch system. The pre-concentration factor for Au(III) ions was found to be at least 100. The analytical parameters of the method were determined and the method was also successfully applied to computer circuit board scrap samples. The reusability of the Au(III)-Imp hydrogel was also determined.

Activation Energy of the Belousov–Zhabotinsky Reaction in a Gel with [Fe(bpy)3] Catalyst

Abstract We synthesized a novel poly(ACMO-co-[Fe(bpy)3]) gel covalently bonded to an Fe-catalyst moiety for the Belousov–Zhabotinsky (BZ) reaction. The novel gel was composed of acryloyl morpholine (ACMO) and bis(2,2′-bipyridine)(4-vinyl-4′-methyl-2,2′-bipyridine)iron bis(hexafluorophosphate) ([Fe(bpy)3]·2PF6). The period of the BZ reaction in the poly(ACMO-co-[Fe(bpy)3]) gel decreased with increasing temperature. The activation energy of the self-oscillation of the gel was found to be 78 kJ mol−1, which is higher than that of the self-oscillating polymer system with [Ru(bpy)3] (about 60 kJ mol−1).

Graft polymerization of acrylamide monomers from polysilsesquioxane containing xanthate groups

Polysilsesquioxanes (PSQs) containing 4-chloromethylphenyl groups were prepared and used for introducing ethylxanthate groups. The obtained PSQs that contained benzyl xanthate structures (XAPSQs) were employed as macroinitiators for grafting acrylamide monomers. The use of XAPSQs for the radical polymerization with acryloylmorpholine (ACMO), N,N-dimethylacrylamide (DMAA) or N-isopropylacrylamide enabled the preparation of the respective grafted PSQ, in which no cross-linked product was formed. The results of the graft polymerizations from XAPSQs supported the interpretation that the reversible addition-fragmentation chain transfer polymerization progressed effectively using the technique known as macromolecular design via the interchange of xanthate. The introduction of polymerized ACMO and DMAA units provided an amphiphilic property to the grafted PSQ. In addition, the PSQs containing poly(ACMO) components showed reversible hydrophobic aggregation behavior at approximately 80°C in aqueous solution. The polysilsesquioxane (PSQ) containing ethylxanthate groups was used for the graft polymerization of several acrylamide monomers by MADIX process. The controlled graft polymerization gave the PSQs containing the polymeric components as the graft chains. The introduction of the polymers provided an amphiphilic property to the polysilsesquioxaneane. In addition, the grafted PSQ containing poly(acryloyl morpholine) showed a thermoresponsive property in an aqueous solution. The reversible hydrophobic aggregation of the polysilsesquioanes was observed at ca. 80°C.