Hydroxyl-containing Polymers Research Articles

Development of Macromolecular Cryoprotectants for Cryopreservation of Cells.

Cryopreservation is a common way for long-term storage of therapeutical proteins, erythrocytes, and mammalian cells. For cryoprotection of these biosamples to keep their structural integrity and biological activities, it is essential to incorporate highly efficient cryoprotectants. Currently, permeable small molecular cryoprotectants such as glycerol and dimethyl sulfoxide dominate in cryostorage applications, but they are harmful to cells and human health. As acting in the extracellular space, membrane-impermeable macromolecular cryoprotectants, which exert remarkable membrane stabilization against cryo-injury and are easily removed post-thaw, are promising candidates with biocompatibility and feasibility. Water-soluble hydroxyl-containing polymers such as poly(vinyl alcohol) and polyol-based polymers are potent ice recrystallization inhibitors, while polyampholytes, polyzwitterions, and bio-inspired (glyco)polypeptides can significantly increase post-thaw recovery with reduced membrane damages. In this review, the synthetic macromolecular cryoprotectants are systematically summarized based on their synthesis routes, practical utilities, and cryoprotective mechanisms. It provides a valuable insight in development of highly efficient macromolecular cryoprotectants with valid ice recrystallization inhibition activity for highly efficient and safe cryopreservation of cells.

Increasing Sedimentation Stability of Cement-Mineral Suspensions by Adding the Hydroxyl-Containing Water-Soluble Polymers

There are the results of studies on increasing the sedimentation stability of cement-mineral suspensions intended to fill hollow spaces in fractured rocky soils and strengthen dispersed soils, as well as to prevent filtration processes in soils.To ensure the sedimentation stability of cement-mineral suspensions, it is proposed to use the water solutions of hydroxyl-containing polymers prone to swelling as a dispersion medium (mixing water): water solutions of polyvinyl alcohol (PVA) in 4% - 8% concentration. The concentration range of polymer solution from 4% to 8% was established in order to prevent coagulation during storage and to ensure the production of polymer films from water PVA solutions.The research results showed that polyvinyl alcohol provides the high kinetic sedimentation stability of cement-mineral systems determined by hydrodynamic factors as follows: the viscosity and density of the water polymer solution. The higher the viscosity and density of the water solution of polyvinyl alcohol (concentration), the higher the sedimentation stability of cement-mineral suspensions.

Design and Synthesis of a Cyclic Double-Grafted Polymer Using Active Ester Chemistry and Click Chemistry via A "Grafting onto" Method.

Combing active ester chemistry and click chemistry, a cyclic double-grafted polymer was successfully demonstrated via a “grafting onto” method. Using active ester chemistry as post-functionalized modification approach, cyclic backbone (c-P2) was synthesized by reacting propargyl amine with cyclic precursor (poly(pentafluorophenyl 4-vinylbenzoate), c-PPF4VB6.5k). Hydroxyl-containing polymer double-chain (l-PS-PhOH) was prepared by reacting azide-functionalized polystyrene (l-PSN3) with 3,5-bis(propynyloxy)phenyl methanol, and further modified by azide group to generate azide-containing polymer double-chain (l-PS-PhN3). The cyclic backbone (c-P2) was then coupled with azide-containing polymer double-chain (l-PS-PhN3) via CuAAC reaction to construct a novel cyclic double-grafted polymer (c-P2-g-Ph-PS). This research realized diversity and complexity of side chains on cyclic-grafted polymers, and this cyclic double-grafted polymer (c-P2-g-Ph-PS) still exhibited narrow molecular weight distribution (Mw/Mn < 1.10).

Facile and efficient bromination of hydroxyl-containing polymers to synthesize well-defined brominated polymers

This article demonstrates a new post-modification method to synthesize well-defined brominated polymers based on the bromination of hydroxyl-containing polymers.

Constructing robust 3-dimensionally conformal micropatterns: vulcanization of honeycomb structured polymeric films

Here, we present the static breath figure process for constructing 3-dimensionally conformal microporous films on nonplanar substrates, with a commercially available triblock polymer, polystyrene-b-polyisoprene-b-polystyrene. The polymer can cover the surface of nonplanar substrates with ordered porous morphology despite the sharp corners and irregular shapes, which was ascribed to the fluid-like character of the matrix. In the subsequent vulcanization, the micro-patterned polymer films were effectively crosslinked and became self-supported even after removing the sacrificial templates. The 3D structures became resistant to a wide range of organic solvents and thermally stable up to 350 °C, an increase of more than 300 K as compared to the un-crosslinked films. The surface features on the 3D structures along the direction of the descending solvent level were investigated in detail by scanning electron microscopy. Furthermore, the versatility of this patterning method was also demonstrated by forming hierarchical micro-structures on bas-relief Si substrates with different patterns. Particularly, hydroxy groups were introduced into another commercially available triblock polymer, polystyrene-b-polybutadiene-b-polystyrene by hydroboration. The functionalized 3D micro-patterns feasible for site-directed grafting were created by the hydroxyl-containing polymers.

Fabrication of robust micro-patterned polymeric films via static breath-figure process and vulcanization

Here, we present the preparation of thermally stable and solvent resistant micro-patterned polymeric films via static breath-figure process and sequent vulcanization, with a commercially available triblock polymer, polystyrene- b-polyisoprene- b-polystyrene (SIS). The vulcanized honeycomb structured SIS films became self-supported and resistant to a wide range of organic solvents and thermally stable up to 350 °C for 2 h, an increase of more than 300 K as compared to the uncross-linked films. This superior robustness could be attributed to the high degree of polyisoprene cross-linking. The versatility of the methodology was demonstrated by applying to another commercially available triblock polymer, polystyrene- b-polybutadiene- b-polystyrene (SBS). Particularly, hydroxy groups were introduced into SBS by hydroboration. The functionalized two-dimensional micro-patterns feasible for site-directed grafting were created by the hydroxyl-containing polymers. In addition, the fixed microporous structures could be replicated to fabricate textured positive PDMS stamps. This simple technique offers new prospects in the field of micro-patterns, soft lithography and templates.

Elucidating Colorization in the Functionalization of Hydroxyl-Containing Polymers Using Unsaturated Anhydrides/Acyl Chlorides in the Presence of Triethylamine

Elucidating Colorization in the Functionalization of Hydroxyl-Containing Polymers Using Unsaturated Anhydrides/Acyl Chlorides in the Presence of Triethylamine

Synthesis and surfactant properties of esters of tall oil fatty acids and hydroxyl-containing polymers

Esters of tall oil fatty acids and hydroxyl-containing polymers were synthesized in the presence of trichloroacetic acid and pyridine. The surfactant properties of the macromolecular esters obtained were evaluated.

Polymeric complexes of chitosan with proteins and hydroxyl-containing polymers

The structures of polymeric complexes of chitosan with methyl cellulose, lactoserum protein, gelatin, and polyvinyl alcohol were simulated on a computer. The mechanism of metal captures in cavities of these complexes was analyzed. The conformational and geometric characteristics of polymeric complexes of chitosan were obtained. The properties and structure of complexes in solutions and in the bulk were examined.

Polymerization of Cyclic Esters in the Presence of Hydroxyl-containing Polymers in DMSO/TBAF

Polymerization of Cyclic Esters in the Presence of Hydroxyl-containing Polymers in DMSO/TBAF

Effect of ammonium orthophosphate on thermochemical transformations of hydroxyl-containing polymers

Ammonium orthophosphate is an active pyrolytic additive for PVA fibre which can increase the yield of CF to 72% of the theoretical carbon content in the polymer. The conditions that ensure obtaining inactivated CFM with 60–85% sorption capacity, at the same level as BAU-grade industrially manufactured activated carbons were found.

Supporting a Metallocene on Functional Polypropylene Granules for Slurry Ethylene Polymerization

We report on the exploration of functional polypropylene as supporting material for homogeneous metallocene catalyst. The copolymerization of propylene and 5-hexenyl-9-BBN by a spherical MgCl2-supported TiCl4 catalyst containing diisobutyl phthalate internal electron donor combined with AlEt3 activator and dimethoxydiphenylsilane external donor afforded isotactic polypropylene granules bearing reactive alkyl-9-BBN groups, which, upon being treated with H2O2/NaOH, resulted in polypropylene granules containing hydroxy functionality. Immobilization of Cp2ZrCl2/MAO was then conducted in toluene solution at an elevated temperature following the procedure of treating the hydroxyl-containing polymers sequentially with MAO and Cp2ZrCl2. Elemental analysis of the Zr contents of the supported catalysts reveals that they are proportional to the concentrations of hydroxy group on the support. In turn, the efficiency of the supported catalysts in slurry ethylene polymerization also exhibits a significant dependency on...

Hybrid Polysaccharide−Silica Nanocomposites Prepared by the Sol−Gel Technique

New monolithic nanocomposite silica biomaterials were synthesized on the basis of various natural polysaccharides and recently introduced completely water-soluble precursor tetrakis(2-hydroxyethyl) orthosilicate. The sol-gel processes were performed in aqueous solutions without the addition of organic solvents and catalysts. The silica polymerization was promoted by the polysaccharides through acceleration and catalytic effect on the processes. By introducing poly(vinyl alcohol) or poly(ethylene oxide) in the precursor solution, it was shown that the jellification took place in the case of the hydroxyl-containing polymer. Therefore, it was suggested that the catalysis was caused by a formation of hydrogen bonds between hydroxyl groups in macromolecules and products of precursor hydrolysis (silanols). It was also demonstrated that the polysaccharides radically changed the structure of biomaterials. In place of the cross-linked nanoparticles, there was a three-dimensional network from crossed or branched fibers and uncrossed spherical particles that filled the mesh space. The density of network, thickness of fibers, and properties of synthesized biomaterials depended on the polysaccharide type, charged degree of their macromolecule, and concentration. By varying these parameters, it was possible to manipulate the structural organization of hybrid polysaccharide-silica nanocomposites.

Poly(N-acryl amino acids): a new class of biologically active polyanions.

Poly(N-acryl amino acids) bearing side groups with a lipophilic character or having charged functional groups (i.e. -NH(2), -COOH, -SH, -OH, and phenols) were synthesized from the radical polymerization of N-acryl amino acid monomers. Monomers were prepared from the reaction of acryloyl chloride and amino acid esters in dry solvents. Polymers of a broad molecular weight ranging from 3 000 to 60 000 Da were obtained. The polymers were optically active, and their structures were confirmed by (1)H NMR and IR spectra and elemental analysis. Hydroxyl-containing polymers were sulfated in high conversion yields by SO(3)/pyridine complex. The newly synthesized linear homopolyanions were tested for heparin-like activities: (i) inhibition of heparanase enzyme, (ii) release of basic fibroblast growth factor (bFGF) from the extracellular matrix (ECM), and (iii) inhibition of smooth muscle cell (SMC) proliferation. Polymers based on tyrosine and leucine were highly active in all three tests (microgram level). Polymers based on phenylalanine, tert-leucine, and proline were active as heparanase inhibitors and FGF release, and polymers of trans-hydroxyproline, glycine, and serine were active only as heparanase inhibitors. The polymer of cis-hydroxyproline was inactive. It was found that a net anionic charge (i.e. carboxylic acid) is essential for biological activity. Thus, methyl ester derivatives of the active polymers, zwitterionic amino acid dependent groups (lysine, histidine), and decarboxylated amino acids (tyramine, ethanolamine) were inactive. The above active polymers did not exhibit anticoagulation activity which is considered the main limitation of heparin and heparinomimetics for clinical use. These synthetic poly(N-acryl amino acids) may have potential use in the inhibition of heparanase-mediated degradation of basement membranes associated with tumor metastasis, inflammation, and autoimmunity.

Miscibility and interpolymer complexation of poly(1-vinyl-imidazole) with hydroxyl- and carboxyl-containing polymers

The miscibility of poly(1-vinylimidazole) (PVI) with some hydroxyl- and carboxyl-containing polymers was studied. Each of the binary blends or complexes of PVI with poly(p-vinylphenol) (PVPh), poly(2-hydroxypropyl methacrylate) (PHPMA) and poly(acrylic acid) (PAA) showed a single glass transition temperature (T g ), indicating miscibility. However, PVI is immiscible with poly(styrene-co-allyl alcohol) (SAA) and poly(hydroxyether of bisphenol-A) (Phenoxy) as shown by the appearance of two T g 's in each of the blends. Based on the frequency shifts of the hydroxyl band of the hydroxyl-containing polymers, the intensities of hydrogen bonding interactions between PVI and hydroxyl-containing polymers are in the order PVPh > PHPMA > SAA and Phenoxy. PVI interacts with PAA via ionic interaction.

Novel crosslinking system with hydroxyl-containing polymer, alicyclic polyepoxide and polyalkoxysilane

The crosslinking system based on the reaction among alicyclic epoxide group, hydroxyl group and alkoxysilyl group in the presence of aluminum β-diketone chelate have been developed. Five kinds of reaction are possible, and the result of gas chromatography and infrared analyses indicated that the main reaction is the ring-opening reaction of alicyclic epoxide group with hydroxyl group and/or hydroxysilyl group. The acrylic resin obtained by free radical polymerization of these three kinds of functional monomers and non-functional monomers showed good curing property, and the film was superior in acid rain resistance and outdoor durability. The resin is suitable to use in automotive 2coat–1bake clear coat. The viscosity of this binder system was remarkably reduced by addition of a low molecular weight alicyclic polyepoxide compound and an alkoxysilane oligomer without affecting to its good curing property. Such a system made it possible to design novel high solid coatings. It was found that the crosslinking could be extended to the combination of a polyester polyol, an alicyclic epoxide compound and an alkoxysilane oligomer. In this case, it was necessary that the polyester polyol contained highly reactive terminal hydroxyl group in the branch chains.

Copolymerization of carbon monoxide and 4-vinylcyclohexene with a palladium catalyst

In this work, carbon monoxide (CO) and 4-vinylcyclohexene (VCH) with [Pd( CH 3 CN) 4 (BF 4 ) 2 were copolymerized under various conditions at 60°C. Elemental analysis and infrared, UV, and NMR spectra indicated that copolymers containing a ketone and a cyclic structure of cyclohexyl and norbornane groups are produced. Bidentate nitrogen ligands proved to be more effective at stabilizing catalytic activity than monodentate phosphorus or nitrogen ligands. Also, the bulk substituent on the bidentate ligand led to inactive catalysts. Methanol served as the coinitiator and chain transfer agent. Increasing the concentration of 4-vinylcyclohexene caused the copolymer 5 CO content to be enhanced. TGA revealed that the copolymer's mass loss starts at 120°C and the maximum peak of decomposition occurs at 450°C. Moreover, X-ray diffraction analysis demonstrated the copolymer to be partially crystalline. Furthermore, reduction of 4-vinylcyclohexene/CO copolymer with LiAlH 4 in THF yields a hydroxyl-containing polymer.

Copolymerization of carbon monoxide and norbornadiene with a palladium catalyst

Carbon monoxide (CO) and norbornadiene (NBD) with Pd(CH 3 CN) 4 (BF 4 ) 2 were copolymerized under various conditions at 50°C. Elemental analysis, infrared spectra, UV, Raman, and NMR spectra showed that the copolymers contained both ketone and unsaturated ring structures. Bidentate nitrogen ligands and phosphorus ligands proved to be more effective at stabilizing catalytic activity than monodentate arsenic ligands or phosphorus ligands. Methanol, protic acid, and an oxidant served as the coinitiator and chain transfer agent, respectively. X-ray diffraction analysis showed the copolymer to be partially crystalline. Thermogravimetric analysis showed that the TG curve for the NBD/CO copolymer has two stages with two maxima peaks at 251 and 470°C. This phenomenon was probably due to increased instability of the copolymers as CO content is increased. Hydrogenation of norbornadiene/CO copolymer with LiAlH 4 and Pd/C in THF yields a hydroxyl-containing polymer and norbornene/CO copolymer, respectively.

Terpolymerization of Styrene, Norbornene, and Carbon Monoxide with a Palladium Catalyst

In this work, the authors conducted the terpolymerization of carbon monoxide (CO), styrene (St), and norbornene (NBE) with Pd(CH3COO)2 in CH3OH under various molar ratios of norbornene to styrene at 90°C. Infrared spectra, 1H NMR and 13C NMR analyses confirmed that the NBE/St/CO terpolymers contain ketone, styrene unit, and ring structure of norbornene. Physical and thermal properties of the NBE/St/CO terpolyrners were also investigated by a differential scanning calorimeter (DSC), thermogravimetric analysis (TGA), solubility and X-ray diffraction analyses. The results indicated that glass transition temperature (Tg) of the terpolymers increased when norbornene was introduced. Terpolymer increased molar ratio of norbornene to styrene was found to not only be more thermally stable, but also to increase solubility. As the NBE/St molar ratio became larger than 0.375 in terpolymer, the terpolymers were soluble in chloroform, tetrahydrofuran (THF), methylene chloride, ethyl acetate, benzene, dimethylacetamide (DMAC), and pyridine. X-Ray diffraction results indicated that the terpolymer increased molar ratio of NBE/St in the terpolymer decreased the degree of crystallinity and the angle of maximum intensity owing to the bulky norbornene group. Hydrogenation of NBE/St/CO terpolymer with a reducing agent yielded a hydroxyl-containing polymer.

Miscibility and interpolymer complexation of poly(2-methyl-2-oxazoline) with hydroxyl-containing polymers

Poly(2-methyl-2-oxazoline) (PMOx) was found to be miscible with poly (styrene-coallyl alcohol), poly(hydroxyether of bisphenol-A), poly (2-hydroxypropyl methacrylate) and poly(p-vinylphenol) (PVPh), when cast from N,N-dimethylformamide solutions and to form interpolymer complexes with PVPh in methanol solutions. The hydrogen bonding interactions between PMOx and hydroxyl-containing polymers were studied by infrared spectroscopy and compared with the corresponding blends of poly(2-ethyl-2-oxazoline) (PEOx). Except with phenoxy, PMOx interacts more strongly with hydroxyl-containing polymers than PEOx does.