Allyl Glycidyl Ether Research Articles

Preparation of a novel melamine foam structure and properties

AbstractMelamine foam is widely used in daily life and building materials due to its superior flame retardancy properties, thermal insulating effects, smoke suppressive ability, low toxicity, and sound absorption properties. To increase the practicality of melamine foam, most research has focused on extending resin storage duration and preparing low‐toxic, high‐strength foam. In this study, allyl glycidyl ether was used to modify melamine resin, and the modified resin was able to demonstrate a longer storage duration as compared to the conventional resins, and the storage time for the modified resin has exceeded 90 days, and a low free formaldehyde content (0.05 ppm). Furthermore, the as‐prepared foam exhibited excellent flame retardancy properties (limiting oxygen index [LOI] = 38.5%, it could easily pass the UL‐94‐0 grade), low‐volume water absorption (0.94%), and lower thermal conductivity (0.0225 W·m−1·K−1). Concurrently, the foam prepared based on the optimal conditions possessed a high compressive strength of 5.08 MPa, which was ca. 17.5 times higher than that of the conventional melamine foam. Thus, it is expected that this melamine resin modification approach can provide a new approach for the preparation of high‐performing foams.

Synthesis of Polyacrylamide‐Based Redox Active Cryogel Using Click Chemistry and Investigation of Its Electrochemical Properties

AbstractFerrocene (Fc) functionalization of macroporous polyacrylamide‐based cryogel (PAAm‐Epx) is achieved by click chemistry. For this purpose, firstly, PAAm‐Epx cryogel with azide functionality (PAAm‐N3) is prepared by using acryalmide (AAm) as the monomer and allyl glycidyl ether (AGE) as the co‐monomer followed by subsequent ring opening reaction of epoxide ring of AGE in acidic medium. Azide groups of PAAm‐N3 is then modified with ethynyl ferrocene, leading to the redox active cryogel (PAAm−Fc) together with preserving the unique characteristic properties of the virgin PAAm‐Epx cryogel. Swelling, mechanical and morphological behaviours of PAAm‐Epx, PAAm‐N3 and PAAm−Fc are investigated. Detailed characterization of the PAAm−Fc is carried out by several techniques such as FTIR (Fourier Transform Infrared Spectroscopy), Scanning electron microscopy with energy dispersive X‐ray spectroscopy (SEM‐EDX), Inductively Coupled Plasma Optical Emmision Spectrometry (ICP‐OES, Cyclic (CV), and Differential Pulse Voltammetry (DPV). Electrochemical analysis confirms the electroactivity and the presence of chemically linked ferrocene unit to the cryogel.

Organocatalyzed Synthesis and Degradation of Functionalized Poly(4-allyloxymethyl-β-propiolactone)s

The chemical synthesis of degradable poly(β-hydroxyalkanoate) (PHA) produced by microorganisms allows the control of the solubility, crystallinity, hydrophobicity, degradability, thermal, and mechanical properties by introducing functionality on the side chain. Herein, we synthesized a PHA derivative containing a pendant allyl group via the anionic ring-opening polymerization of a 4-allyloxymethyl-β-propiolactone (AMPL) monomer, which was prepared via the carbonylation of allyl glycidyl ether. The AMPL monomer was subjected to various organocatalysts in bulk to yield poly(4-allyloxymethyl-β-propiolactone) (PAMPL) with controllable molecular weight and dispersity. The prepared PAMPL polymers were characterized via 1H and 13C NMR, gel permeation chromatography (GPC), differential scanning calorimetry (DSC), and matrix-assisted laser desorption/ionization-time-of-flight (MALDI-TOF) analyses. A photoactivated thiol–ene reaction allowed the postpolymerization modification of PAMPLs with varying substituents. Functionalized PAMPL polymers degraded under chemical and thermal conditions, and importantly, cross-linked PAMPL films degraded during exposure to soil and seawater under a wide range of degradation kinetics. This study provides the future potentials of the chemically synthesized and functionalized PHA for replacing conventional petroleum-derived polymers.

Transparency- and Repellency-Enhanced Acrylic-Based Binder for Stimuli-Responsive Road Paint Safety Improvement Technology.

In the current study, an acrylic polymer binder applicable to road signs was successfully developed by mixing various acrylic, acrylate-type, and photoinitiator-based monomer species at different acrylate series/silicone acrylate ratios. An amorphous acrylic monomer was used, and the distance between the polymers was increased to improve transparency. The binder was designed with the purpose of reducing the yellowing phenomenon due to resonance by excluding the aromatic ring structure, which is the main cause of yellowing. The optical properties of the binder were determined according to the content of n-butyl methacrylate/methyl methacrylate and the composition of the crosslinking agent in the formulation. Allyl glycidyl ether and dilauroyl peroxide were used to improve the yellowing problem of benzoyl peroxide, an aromatic photoinitiator. Adding a silicone-based trivalent acrylic monomer, 3-(trimethoxysilyl)propyl methacrylate (TMSPMA), was also found to have a significant effect on the transparency, shear properties, and water resistance of the binder. When 15 wt% TMSPMA was added, the best water repellency and mechanical properties were exhibited. The surface morphology of the improved binder and the peeling part were confirmed using field emission scanning electron microscopy. The acrylic polymer developed in this study can be applied in the coating and adhesive industries.

Polymerization of Allyl Glycidyl Ether under the Action of the BF3–H2O Catalytic System

Polymerization of Allyl Glycidyl Ether under the Action of the BF3–H2O Catalytic System

Thermoresponsive properties of star-shaped amphiphilic block copolymers with a cholic acid core and functional amine groups

Block copolymers having stimuli-responsive properties are gaining impetus in the design of drug and gene delivery systems for therapeutic purposes. Thermoresponsive polymers are particularly interesting due to the ease of control over their solution behavior in aqueous media. The fine tuning of the lower critical solution temperature (LCST) of such polymers is necessary to achieve a successful drug delivery. In this work, the thermoresponsive properties of block copolymers based on a bile acid are studied in aqueous media to determine the factors affecting the LCST. Poly(allyl glycidyl ether) (PAGE) and poly(ethylene glycol) (PEG) blocks were grafted from a cholic acid (CA) core to yield star-shaped block copolymers with 4 arms. The PAGE block was further functionalized to bear pendant amine groups. The addition of amine groups may be expected to improve the hydrophilicty of the polymers, but the functionalized polymers showed pronounced thermoresponsive properties and aggregation under physiological conditions. It is thus necessary to understand the changes of their solution properties for a better design of such polymers for drug delivery applications. In this work, we studied the effects of PEG length and of the amine groups on the LCST behavior in water at various salt concentrations. A shorter PEG chain of 21 repeat units shows a LCST of 16 °C, whereas a longer PEG of 41 repeat units failed to show thermoresponsiveness up to 80 °C and at concentrations up to 50 mg/mL. Functionalizing the allyl groups increased the LCST of the polymers. A salting-out effect was observed by a decrease in LCST and the presence of salt also promoted precipitation of the nanoparticles.

Preparation and Characterization of the Molybdenum Disulfide Nanosheets Coated with Poly‐(NVCL‐co‐AGE))/MA for the Anticancer Drug Delivery Light

AbstractA novel thermosensitive polymer (poly‐(NVCL‐co‐AGE))/MA was synthesized by N‐vinylcaprolactam (NVCL), 5‐Amino‐2‐hydroxybenzoic acid (Mesalamine, MA) and allyl glycidyl ether (AGE). The obtained polymeric matrix is functionalized on molybdenum disulfide nanosheets (MNs (which is used as a drug carrier for efficient drug delivery. The ability of MNs ‐ (poly‐(NVCL‐co‐AGE))/MA was estimated as a nanocarrier for the delivery of imatinib mesylate (IM) as an antitumor drug. The resulting polymer was confirmed by FESEM/EDX, TEM, XRD, FTIR, TGA, and UV‐Vis spectroscopy. The impacts of various variables such as pH, contact time, and temperature on the adsorption efficiency were also evaluated. Kinetic and isotherm studies of IM adsorption demonstrated that the adsorption of IM on the surface of MNs ‐ (poly‐(NVCL‐co‐AGE))/MA was well fitted to the pseudo‐second‐order kinetic and Langmuir isotherm models, respectively. On the other hand, we were interested in estimating drug release kinetics and in vitro release behavior of IM loaded on MNs ‐ (poly‐(NVCL‐co‐AGE))/MA. In vitro controlled drug release and phototherapy under near‐infrared (NIR) light irradiation are also discussed. The existence of absorbed NIR energy causes shrinkage of thermo‐sensitive polymer chains and successfully caused the drug release. In vitro drug release of MNs ‐ (poly‐(NVCL‐co‐AGE))/MA was comparatively carried out at 37 and 50 °C. The release rate of MNs ‐ (poly‐(NVCL‐co‐AGE))/MA at 50 °C was much higher than those at 37 °C. Also, the drug release behavior after the involvement of NIR light irradiation reached up to 98 % over 15 min, which was about 11 times that without NIR light irradiation.

Interaction of Linear Polyelectrolytes with Proteins: Role of Specific Charge-Charge Interaction and Ionic Strength.

We present a thermodynamic study of the interaction of synthetic, linear polyelectrolytes with bovine serum albumin (BSA). All polyelectrolytes are based on poly(allyl glycidyl ether) which has been modified by polymer-analogous reaction with anionic (-SO3Na), cationic (-NH3Cl or -NHMe2Cl) or zwitterionic groups (-NMe2(CH2)3SO3). While the anionic polymer shows a very weak interaction, the zwitterionic polymer exhibits no interaction with BSA (pI = 4.7) under the applied pH = 7.4, ionic strength (I = 23–80 mM) and temperature conditions (T = 20–37 °C). A strong binding, however, was observed for the polycations bearing primary amino or tertiary dimethyl amino groups, which could be analysed in detail by isothermal titration calorimetry (ITC). The analysis was done using an expression which describes the free energy of binding, ΔGb, as the function of the two decisive variables, temperature, T, and salt concentration, cs. The underlying model splits ΔGb into a term related to counterion release and a term related to water release. While the number of released counter ions is similar for both systems, the release of bound water is more important for the primary amine compared to the tertiary N,N-dimethyl amine presenting polymer. This finding is further traced back to a closer contact of the polymers’ protonated primary amino groups in the complex with oppositely charged moieties of BSA as compared to the bulkier protonated tertiary amine groups. We thus present an investigation that quantifies both driving forces for electrostatic binding, namely counterion release and change of hydration, which contribute to a deeper understanding with direct impact on future advancements in the biomedical field.

Functional Polyglycidol-Based Block Copolymers for DNA Complexation.

Gene therapy is an attractive therapeutic method for the treatment of genetic disorders for which the efficient delivery of nucleic acids into a target cell is critical. The present study is aimed at evaluating the potential of copolymers based on linear polyglycidol to act as carriers of nucleic acids. Functional copolymers with linear polyglycidol as a non-ionic hydrophilic block and a second block bearing amine hydrochloride pendant groups were prepared using previously synthesized poly(allyl glycidyl ether)-b-polyglycidol block copolymers as precursors. The amine functionalities were introduced via highly efficient radical addition of 2-aminoethanethiol hydrochloride to the alkene side groups. The modified copolymers formed loose aggregates with strongly positive surface charge in aqueous media, stabilized by the presence of dodecyl residues at the end of the copolymer structures and the hydrogen-bonding interactions in polyglycidol segments. The copolymer aggregates were able to condense DNA into stable and compact nanosized polyplex particles through electrostatic interactions. The copolymers and the corresponding polyplexes showed low to moderate cytotoxicity on a panel of human cancer cell lines. The cell internalization evaluation demonstrated the capability of the polyplexes to successfully deliver DNA into the cancer cells.

Surfactant-Emulating Amphiphilic Polycarbonates and Other Functional Polycarbonates through Metal-Free Copolymerization of CO2 with Ethylene Oxide

Three types of ethylene oxide-based and carbonate-containing copolymers were prepared through copolymerization of ethylene oxide (EO) with CO2 under metal-free conditions in the presence of triethylborane (TEB), using onium salts (OS) as initiator. Hydrophobic poly[(ethylene carbonate)x-co-(ethylene oxide)y] (PECEO) samples with carbonate contents above 90% (x ≫ y) were first prepared under a CO2 pressure of 10–30 bar with a ratio of [TEB] to [OS] of 1–1.2 equiv in tetrahydrofuran (THF) or in hexane. The above PECEO (carbonate > 91%) then served as a macroinitiator to grow two external poly(ethylene oxide) (PEO) blocks and generate in one-pot amphiphilic PEO-b-PECEO-b-PEO triblocks. Lastly, the copolymerization of EO under a low pressure of CO2 (1–2 bar) with a ratio of [TEB] to [OS] of 1.2–2.0 equiv afforded hydrophilic poly[(ethylene oxide)y-co-(ethylene carbonate)x] (PEOEC) random copolymers with carbonate contents below 10% (y ≫ x); allyl glycidyl ether (AGE) was also terpolymerized with EO and CO2 under the same conditions to introduce functional groups along the backbone of PEO chains. Critical micelle concentrations (CMC) and size of micelles were measured for amphiphilic PEO-b-PECEO-b-PEO samples and compared with the values of other nonionic surfactants. The properties of “PEO-like” hydrophilic PEOECs were characterized by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and wettability test; their degradation behavior was further investigated under different conditions.

Non-intuitive Trends in Flory–Huggins Interaction Parameters in Polyether-Based Polymers

Recently, a variety of “click” or other additive chemistries have been introduced to functionalize polymers after polymerization to target specific applications, for example, membranes, catalysis, or drug delivery systems. It is generally assumed that the inclusion of these “click” linking groups has minimal impact on the thermodynamics of the polymer as a whole. In this study, we demonstrate that the introduction of these click-derived units has a profound impact on the Flory–Huggins parameter of polyether derivatives. Using random phase approximation fits for small-angle X-ray scattering data from block copolymer pairs to estimate the Flory–Huggins interaction parameter (χ), we determined that poly(ethylene oxide) (PEO) and poly(allyl glycidyl ether) (PAGE), which differ only by the inclusion of an allyl sidechain, have a χ of 0.030 (at T = 34 °C). While PEO is miscible with poly(lactide) (PLA) at nearly all temperatures, the PLA/PAGE χ determined experimentally is 0.015 (at T = 30 °C). Atomistic molecular dynamics simulations of PEO/PAGE oligomer blends show that upon blending, PEO chains contract and move closer together, while PAGE chains stretch and spread apart, indicating an enthalpic contribution to the χ parameter due to changes in polymer coordination resulting from the conformational asymmetry of PAGE and PEO. These studies demonstrate the large impact that functionalization and side-chain units have on the χ parameter of polymer pairs.

Al(III) phthalocyanine catalysts for CO2 addition to epoxides: Fine-tunable selectivity for cyclic carbonates versus polycarbonates

A sustainable synthetic methodology to prepare bifunctional cationic imidazolyl and neutral tert-butylphenoxy Al(III)-phthalocyanine complexes is described, using ultrasound irradiation to synthesize the phthalonitrile precursors, followed by microwave-assisted cyclotetramerization. The metallophthalocyanine catalysts were applied in the coupling reaction of CO2 with epoxides, where the structure of the phthalocyanine was shown to determine the reaction selectivity towards the formation of cyclic carbonates versus polycarbonates. The cationic imidazolyl phthalocyanines operate as efficient bifunctional catalysts to promote the CO2 cycloaddition to terminal epoxides (styrene oxide, epichlorohydrin, propylene oxide and allyl glycidyl ether), leading to TONs up to 1414 and 100% selectivity for cyclic carbonates, without the need of using any co-catalyst. On the other hand, the neutral 4-tert-butylphenoxy Al(III) phthalocyanine catalyzed the copolymerization reaction between CO2 and cyclohexene oxide, in the presence of PPNCl as co-catalyst, with TON = 814, providing the first example of a metallophthalocyanine catalyst with full selectivity for formation of polycarbonates.

Design of 3-aminophenol-grafted polymer-modified zinc sulphide nanoparticles as drug delivery system.

Zinc sulphide (ZnS) nanoparticles were synthesized by the coprecipitation method. The ZnS nanoparticle surface was polymerized with allyl glycidyl ether (AGE), and 3‐aminophenol was then deposited as a ligand on nanosorbent. The modified nanosorbent was investigated with Fourier transform infrared spectroscopy and thermogravimetric analysis. The particle size of the modified nanosorbent was studied with scanning electron microscopy. Some characteristic factors of the adsorption process such as pH and time were investigated for famotidine using the modified nanosorbent. The equilibrium adsorption study of famotidine by 3‐aminophenol‐grafted AGE/ZnS was analysed by adsorption isotherms of the Langmuir, Freundlich, and Temkin models. The famotidine‐releasing process was investigated in simulated biological fluids (intestinal fluid at pH of 7.4 and gastric fluid at pH of 1.2) and demonstrated 65% and 73% famotidine release during periods of 30 h (pH = 7.4) and 60 min (pH = 1.2), respectively. These results reveal the optimal performance of 3‐aminophenol‐grafted AGE/ZnS for sustained drug delivery.

PH-tunable nanoparticles composed of copolymers of lactide and allyl-glycidyl ether with various functionalities for the efficient delivery of anti-cancer drugs

The designing of biocompatible nanocarriers for the efficient delivery of their cargos to the desired targets remains a challenge. In this regard, the most promising strategy relies on the construction of pH- or thermo-responsive nanoparticles (NPs). However, it is also important to preserve the balance between the responsiveness of the carrier and their stability in physiological conditions. Therefore, we described a new family of copolymers of lactide and allyl-glycidyl ether which were subsequently modified by thiol-ene reaction to functionalize the resulting copolymer with acetylcysteine (ACC) or thioglycolic acid (tGA) moieties. Subsequently, these copolymers were used to obtain blank and doxorubicin (DOX) loaded NPs with an average diameter of about 50−100 nm. Interestingly, the NPs were stable in different pH conditions, however, the presence of ACC or tGA units in the polymeric chain allows for the reduction of the undesired burst release due to the supramolecular interactions between polymeric pedant groups and DOX. The release tests of DOX from NPs showed that DOX release rate decrease depending on the pH values and the copolymer functionalization in order of non-modified NPs > ACC-modified NPs > tGA functionalized NPs. Most importantly, the MTT assay showed that all blank NPs are non-toxic against the normal L929 cell line. Subsequently, the antitumor efficiency of the obtained NPs was tested towards L929 (murine fibroblast cell line), HeLa (cervical cancer), and AGS (human gastric adenocarcinoma cancer) cells. The results demonstrated that DOX-loaded NPs efficiently induce the reduction in the viability of the HeLa and AGS cell, and this reduction in the viability was even below 20 % for the AGS cells. Together with their biocompatibility, the obtained NPs offer a novel route for the preparation of nanocarriers for the controlled and efficient delivery of anticancer drugs.

Tailor-made magnetic nanocomposite with pH and thermo-dual responsive copolymer brush for bacterial separation

Rapid detection of pathogenic bacteria particularly in food samples demands efficient separation and enrichment strategies. Here, hydrophilic temperature-responsive boronate affinity magnetic nanocomposites were established for selective enrichment of bacteria. The thermo-responsive polymer brushes were developed by surface-initiated atom transfer radical polymerization of N-isopropylacrylamide (NIPAm) and allyl glycidyl ether (AGE), followed by a reaction of epoxy groups, and incorporation of fluorophenylboronic acid. The physical and chemical characteristics of the magnetic nanocomposites were analyzed systematically. After optimization, S. aureus and Salmonella spp. showed high binding capacities of 32.14 × 106 CFU/mg and 50.98 × 106 CFU/mg in 0.01 M PBS (pH 7.4) without bacteria death. Bacterial bindings can be controlled by altering temperature and the application of competing monosaccharides. The nanocomposite was then utilized to enrich S. aureus and Salmonella spp. from the spiked tap water, 25% milk, and turbot extraction samples followed by multiplex polymerase chain reaction (mPCR), which resulted in high bacteria enrichment, and demonstrated great potential in separation of bacteria from food samples.

Fabrication and performance of shape‐stable phase change materials based on epoxy group crosslinking

AbstractShape‐stable phase change materials (SSPCMs) have attracted increased attention as they can be used in applications such as solar energy storage materials and smart textiles. Hexadecyl acrylate (HDA) was free‐radical copolymerized with allyl glycidyl ether (AGE) to form a copolymer with epoxy groups. It was further solidified with diethylenetriamine to form a series of novel SSPCMs. HDA could be limited to a stable 3D cross‐linking network constructed from epoxy groups, giving PCM excellent shape stability. Infrared spectroscopy and hydrogen nuclear magnetic spectroscopy showed the successful fabrication of poly(hexadecyl acrylate) (PHDA) with epoxy group. The maximum enthalpies of the SSPCMs with 5 wt% AGE during heating and cooling were 86 and 86 J/g, respectively, which indicated that they have good thermal energy storage densities. The initial melting and freezing temperatures were 32 and 29°C, respectively, which were within the comfortable temperature range of human body. In addition, the thermal decomposition temperature of SSPCMs was higher than 270°C. After 50 thermal cycles, the materials still showed excellent phase change performances. Moreover, the specimen with low degree of cross‐linking had similar temperature control and thermal response capabilities to PHDA. These SSPCMs exhibited excellent thermal performance, thermal reliabilities, and stabilities. Therefore, they were expected to be applied in various applications, including solar energy storage, energy‐saving buildings, and wearable temperature control textiles.

Allyl Glycidyl Ether-modified Animal Glue Binder for Improved Water Resistance and Bonding Strength in Sand Casting

This paper aims to develop a modified animal glue sand binder for foundry casting with improved water resistance and bonding strength. An efficient method is reported by using sodium hydroxide as the catalyst to improve the operability of animal glue binder and allyl glycidyl ether as the modifier to improve the water resistance and bonding strength. Sand specimens prepared using allyl glycidyl ether-modified animal glue binder were cured by compressed air at room temperature. The proposed method saves energy and is environmentally friendly and inexpensive. Compared with unmodified animal glue binder, standard dog bone sand specimens with allyl glycidyl ether-modified animal glue binder had higher tensile strength of 2.58 MPa, flowability of 1.95 g, better water resistance (a lower decrease in tensile strength at 25 °C and relative humidity of 60%), and good collapsibility. This allyl glycidyl ether-modified animal glue binder is suitable for practical application in the foundry industry

Performance of phospho-L-tyrosine immobilized onto alginate/polyacrylamide-based cryogels: Effect of ligand coupling on human IgG adsorption and Fab fragments separation

The ortho-phospho-tyrosine (P-Tyr) pseudoaffinity ligand was immobilized via ether linkage onto polyacrylamide-alginate (PAAm-Alg)-epoxy cryogels prepared according to two different approaches in order to explore their performance in the immunoglobulin G (IgG) purification from human serum. In the first approach, the P-Tyr was attached to cryogel prepared by cryocopolymerization of acrylamide and alginate with allyl glycidyl ether (AGE) as functional comonomer, and methylenebisacrylamide and Ca(II) as crosslinkers, obtaining the PAAm-Alg-AGE-P-Tyr. In the second approach, the PAAm-Alg was synthesized under the same conditions, but without AGE, and the P-Tyr was coupled to epichlorohydrin (ECH)-activated cryogel, obtaining the PAAm-Alg-ECH-P-Tyr. Both pseudoaffinity cryogels were characterized by scanning electron microscopy, swelling tests, porosity, ligand density, and flow dynamics. The human IgG differently interacted with the PAAm-Alg-ECH-P-Tyr and PAAm-Alg-AGE-P-Tyr cryogels, depending on the pH and adsorption buffer system used. The selectivity analyzed by electrophoretic profiles was similar for both cryogels, but PAAm-Alg-ECH-P-Tyr achieved higher IgG adsorption capacity (dynamic capacity of 12.62 mg of IgG/mL of cryogel). The IgG purity assayed by ELISA was 95%. The maximum IgG adsorption capacity and dissociation constant of the PAAm-Alg-ECH-P-Tyr, determined by Langmuir isotherm, were found to be 91.75 mg IgG/g of dry cryogel and 4.60 × 10−6 mol/L at pH 6.0 from aqueous solutions. The PAAm-Alg-AGE-P-Tyr showed potential to purify the Fab fragments from papain-digested human IgG solution at pH 7.0. Fab fragments were separated from Fc fragments (but with uncleaved IgG) in eluted fractions (analyzed by the Western blot technique), with yield of 82% and purity of 95% (determined by radial immunodiffusion).

Degradable allyl Antheraea pernyi silk fibroin thermoresponsive hydrogels to support cell adhesion and growth.

At present, Antheraea pernyi silk fibroin (ASF) based hydrogels have wide potential applications as biomaterials because of their superior cytocompatibility. Herein, ASF is used as a nucleophilic reagent, reacted with allyl glycidyl ether (AGE) for the preparation of allyl silk fibroin (ASF-AGE). The investigation of ASF-AGE structure by 1H NMR and FTIR are revealed that reactive allyl groups were obtained on ASF by nucleophilic substitution. A series of ASF based hydrogels are manufactured by N-isopropylacrylamide (NIPAAm) copolymerization bridged with ASF-AGE. By the silk fibroin self-assembly process, stably physical cross-linked hydrogels are formed without any crosslinking agent. These hydrogels exhibit good thermoresponsive and degradability, for which the LCST was about 32 °C, and these hydrogels can be degraded in protease XIV solution. Excellent cell proliferation, viability and morphology is demonstrated for b End.3 cells on the hydrogels by the characteristic MTT assay, CLSM and SEM. The cytocompatibility of b End.3 cells was demonstrated with excellent cell adhesion and growth on these ASF based hydrogels in vitro. These degradable and thermoresponsive ASF based hydrogels may find potential applications for cells delivery devices and tissue engineering.

A new approach to prepare Polyethylene Glycol Allyl Glycidyl Ether

The polyethylene glycol allyl glycidyl ether (PGAGE) is an important intermediate for preparing silicone softener that can be synthesized from allyl alcohol polyoxyethylene ether and epichlorohydrin (ECH). The performance parameters including the concentration of ECH, initial boron trifluoride diethyl etherate (BFEE) as well as CaCl2 quality were investigated respectively. The optimum process parameters which can get high capping and low by-product rate are as follows: the ECH concentration is 2.0 M, the initial BFEE concentration is 1.65mM, and the CaCl2 dosage is 1.65g/L. Under these conditions, the maximal yield can be improved to 91.36%, the percent of capping rate is higher than 98.16%, the residual concentration of F-is only 0.63 mg/L.