Solution Polymerization Method Research Articles

Chemical synthesis and characterization of high molecular weight poly(2,2'-dithiodianiline) (PDTDA)

A high molecular weight poly(2,2'-dithiodianiline) (PDTDA) was chemically synthesized by simple solution polymerization method. The weight average molecular weight was observed to be 424,690 by GPC analysis. The chemical structure of the undoped PDTDA was characterized by UV/VIS spectroscopy. It was confirmed that the S-S bonds within repeating units could be conserved well after chemical polymerization by FTIR spectroscopic analysis.

Synthesis and characterization of new thermally stable polybenzimidazoles and poly(amide-benzimidazole)s

Benzofuro[2,3-b]benzofuran-2,9-dicarboxyl-bis-phenylamide-4,4 ′-dicarboxylic acid was synthesized as a new monomer, and characterized by means of IR, 1 HNMR and MS spectroscopy. A series of polybenzimidazoles (PBIs) were prepared from this diacid that were considered as poly(amide-benzimidazole)s and also, some new PBIs were synthesized from benzofuro[2,3-b]benzofuran-2,9-dicarboxylic acid and several aromatic tetraamines by solution polymerization method in polyphosporic acid as solvent. Thermal properties of these polymers were compared. The results showed that all of the PBIs had good thermal stabilities.

Swelling equilibria of polymeric hydrogels containing poly(acrylamidesodiumallylsulfonate-acrylic acid)

The superabsorbent poly(AM-SAS-AA)s were synthesized to improve the water absorption capacities in comparison with the poly(AM-SAS) by an aqueous solution polymerization method from acrylamide (AM), sodium allylsulfonate (SAS), and acrylic acid (AA). The reaction conditions were controlled by varying the AA concentrations and fixing other agent concentrations to obtain the optimal superabsorbent poly(AM-SAS-AA). The poly(AM-SAS-AA) showed maximal absorption capacity at 0.3 mol/L among AA concentrations from 0.053mol/L to 0.4 mol/L. The water absorption capacities of poly(AM-SAS-AA)s prepared at the optimal reaction condition were measured within the temperature ranges from 298.15K to 318.15K. Those experimental data were used to describe the effect factors on absorption capacities and swelling equilibria data among those data were correlated with the swelling models to estimate the interchange energy parameters. Each swelling models combined with group contribution models (UNIFAC, ASOG) was introduced to calculate the swelling equilibria of water(1)/poly(AM-SAS-AA)(2) systems. The swelling behaviors could be described by the estimated parameters, and the calculated values agreed well with the experimental data.

Measurement and calculation of swelling equilibria for water/poly(acrylamide-sodiumallylsulfonate) systems

Superabsorbent poly(acrylamide-sodiumallylsulfonate) was synthesized from acrylamide (AM) and sodiumallylsulfonate (SAS) by a solution polymerization method. N,N’-methylenebisacrylamide (BIS) was used as the crosslinker; potassium persulfite (PP) and N,N,N’,N’-tetra-methylenediamine (TMEDA) were used as the redox initiator during the synthesis. The absorption capacities of the synthesized superabsorbent poly(AM-SAS) were repeatedly measured to obtain the optimal poly(AM-SAS) according to the variations of monomer concentration at 298.15 K. Its maximal absorption capacity appeared as 811 times at 0.1 mol/L among from 0.01 mol/L to 0.16 mol/L of SAS concentrations. The swelling equilibria at those conditions from 298.15 K to 318.15 K were measured and used to estimate the parameters by correlating with the Flory-Huggins model. The swelling behavior could be described by the parameters and the calculated values agreed satisfactorily with the experimental data.

Miscibility of the segmented polyurethane blends with chlorinated poly(vinyl chloride)

The miscibility of a series of segmented polyurethane (SPU) blends with chlorinated poly(vinyl chloride) (CPVC) was investigated by differential scanning calorimetry (DSC) and Fourier-transform infrared (FTIR) spectroscopy. The segmented polyurethanes based on p, p-diphenylmethane diisocynate (MDI) with 1,4-butanediol (BDO) were synthesized by a two-step, solution polymerization method. DSC results demonstrated that the polyester polyurethane blend with CPVC formed a miscible system, whereas the polyether polyurethane–CPVC blend was an immiscible one. Increasing the molecular weight of the glycol can decrease the miscibility due to the crystallizability of the soft segment. FTIR spectroscopic results showed a strong interaction between CPVC and the polyester soft segment. In addition, it was found that the miscibility of SPU and CPVC decreased upon increasing the hard segment content.

Comparison of octadecyl bonded titania phases

The structure of a C18 phase based on titania (C18-A), synthesized by the method of solution polymerization, is investigated by diffuse reflectance infrared Fourier transform (DRIFT) and solid-state nuclear magnetic resonance (NMR) spectroscopy. The findings are compared with the results of a second C18 phase based on titania (C18-B) which was synthesized by the method of surface hydrosilation. The dynamic behavior of both phases is examined by1H MAS NMR detection of spinlattice relaxation times in the rotating frame (T1pH) and conventional spin-lattice relaxation times (T1). Due to a smaller ligand density, phase C18-A appears to be a somewhat more mobile than phase C18-B.

Microporous segmented polyetherurethane vascular graft: I. Dependency of graft morphology and mechanical properties on compositions and fabrication conditions.

The influence of polyurethane compositions and fabrication conditions on the pore morphology and mechanical properties of microporous segmented polyetherurethane (SPEU) grafts, which were produced by the coagulation technique, were carefully investigated in this article. SPEU resins based on polytetramethylene oxide (PTMO) were synthesized by the solution polymerization method. Different types of coagulant were adapted to examine the feasibility of producing a microporous SPEU graft with good structural regularity. The experimental results indicate that a microporous SPEU graft with a uniform pore structure can be fabricated quite conveniently by using a proper concentration of water and ethanol mixed coagulant. Tensile tests demonstrated that the fabricated microporous SPEU grafts possess high mechanical strengths and satisfy the requirements as vessel replacements. The burst strength test also revealed that the SPEU graft can sustain extremely high internal pressure. Furthermore, a high compliant SPEU (high porosity) graft can be obtained by blending a proper amount of "soluble filler" (i.e., free PTMO polyol in this study) into the SPEU resin.

Synthesis of D(+)-1-Phenylethyl Acrylate in Organic Solvents Catalyzed by Lipase and Its Polymer.

Lipase-catalyzed transesterification of vinyl acrylate (VA) with D, L-1-phenylethanol was carried out to synthesize D (+)-1-phenylethyl acrylate (PEA) in organic solvents, Lipase OF was the most appropriate enzyme for the synthesis of PEA among four kinds of lipases studied. The conversion to PEA increased with increasing lipase OF concentration. Isooctane was the most appropriate solvent among three kinds of solvents studied. While PEA was synthesized when VA was used as an acylating agent, it was hardly synthesized with acrylic acid or ethyl acrylate. The conversion to 1-phenylethyl methacrylate using vinyl methacrylate or methacrylic anhydride as an acylating agent was much lower than that of PEA. The formation of PEA was confirmed by 1H-NMR spectrum. The optical purity of PEA was 100%. Optically active polymer having molecular weight of about 30, 000 was obtained by a solution polymerization method.

Synthesis and characterization of novel polyarylates from 2,5-bis(4-hydroxyphenyl)-3,4-diphenylpyrrole and various aromatic dicarboxylic acids

A new tetraphenylated heterocylic diol, 2,5-bis(4-hydroxyphenyl)-3,4-diphenylpyrrole, was synthesized in three steps starting from 4-methoxydeoxybenzoin. The tetraphenylpyrrole-containing polyarylates having inherent viscosities of 0.28–0.88 dL/g were prepared from the diol and various aromatic dicarboxylic acid chlorides by both phase transfer catalyzed two-phase polycondensation and high temperature solution polymerization methods. All the polyarylates were semi-crystalline, and were readily soluble in a variety of solvents including N-methyl-2-pyrrolidone, m cresol, pyridine, and 1,4-dioxane. These polymers had glass transition temperatures in the range of 223–279°C, with no weight loss below 400°C in both air and nitrogen atmospheres. © 1994 John Wiley & Sons, Inc.

13-Nuclear Magnetic Resonance Studies of Polyetherurethaneureas

Abstract A series of linear polyurethaneureas was prepared by a two-step solution polymerization method. The prepolymer formed by the reaction of 4,4′-diphenyl methane diisocyanate with polyethylene glycol/polypropylene glycol was further chain extended with ethylene diamine/propane diamine/hexane diamine. The chemical shift values of various carbon species of the block copolymer were analyzed and assigned. The products formed due to the presence of water at different stages of polymerization were also characterized.

Colouration of rhodamine B in PMMA by aqueous HCl solution and in the copolymer of methyl methacrylate with methacrylic acid

A rhodamine B doped PMMA sample is made by the solution polymerization method. It is found that the reddish colour of rhodamine B molecules reduces greatly during polymerization and that the once reduced colour of rhodamine B recovers by immersion of the sample in aqueous HCl solution. Discolouration of rhodamine B is diminished in the copolymer of methyl methacrylate with methacrylic acid.

Formaldehyde polymers, 25. Copolymerization of 6,8‐dimethyl‐4‐oxo‐5‐chromanylmethyl acrylate with styrene, methyl methacrylate, and vinyl chloride

AbstractThe free radical copolymerizations of 6,8‐dimethyl‐4‐oxo‐5‐chromanylmethyl acrylate (DCA) with styrene (St), methyl methacrylate (MMA), and vinyl chloride (VC) by the solution polymerization method were studied. For copolymerization of DCA(M1) with St(M2), the reactivity ratios were r1=0,32, r2=0,70; with MMA(M2) they were r1=0,43, r2=2,00; and with VC(M2) they were r1=4,00, r2=0,08. The Q and e values for DCA were 0,54 and 0,42, respectively. It was also shown that the chromanone skeleton acts as UV‐absorber, and inhibits photodegradation of the copolymers.

Copolymerization of Tri-n-butyltin Acrylate and Tri-n-butyltin Methacrylate Monomers with Vinyl Monomers Containing Functional Groups

Abstract A new approach to obtaining thermoset organotin polymers, which permits control of crosslinking site distribution and, through it, a better control of properties of organotin antifouling polymers, is reported. Tri-n-butyltin acrylate and tri-n-butyltin methacrylate monomers were prepared and copolymerized, by the solution polymerization method with the use of free-radical initiators, with several vinyl monomers containing either an epoxy or a hydroxyl functional group. The reactivity ratios were determined for six pairs of monomers by using the analytical YBR method to solve the differential form of the copolymer equation. For copolymerization of tri-n-butyltin acrylate (M1) with glycidyl acrylate (M2), these reactivity ratios were n = 0.295 ± 0.053, r2 = 1.409 ± 0.103; with glycidyl methacrylate (M2) they were r1 = 0.344 ± 0.201, r2 = 4.290 ± 0.273; and with N-methylolacrylamide (M2) they were r1 = 0.977 ± 0.087, r2 = 1.258 ± 0.038. Similarly, for the copolymerization of tri-n-butyltin methacryl...

Thermal properties and solubility of poly‐1,4,5,8‐naphthalenetetracarboxydiimides containing 1,3,5‐triazine rings

AbstractAromatic polyimides were synthesized by polymerization of 1,4,5,8‐naphthalenetetracarboxylic dianhydride and 2‐dialkylamino‐4,6‐dihydrazino‐1,3,5‐triazines by a solution polymerization method followed by cyclodehydration. The polyimides had number‐average molecular weights over 13,000–16,000 or viscosity values of 0.23–0.65 dl/g. The x‐ray diffraction diagram of polyimide I showed a crystal pattern, but the pattern became less pronounced with increasing length of the polymer side chain, and thus polyimide V showed a typical amorphous pattern. Study of the thermal stability of the polyimides by thermogravimetric analysis showed that a steep weight loss occurred in the range 380–410°C. Among the polyimides, I had only poor solubility in organic solvent, while IV and V were soluble even in general organic solvents such as tetrahydrofuran and dioxane.

Photocrosslinkable polyphosphonates having unusual resistance to acids

AbstractThe resistance of various linear condensation polymers to acid or base hydrolysis is dependent upon the nature of the linkages in the polymer chain. Aryl polysulfonates having a styrylketone sensitizing group have been shown to be particularly resistant to attack by strong bases. Similar phosphorouscontaining polymers have been prepared and those with the arylphosphonate, thiophosphonate, and phosphate linkages have been found resistant to attack by such acids as ferric chloride. Using a solution polymerization method, these phosphorous polymers and also those containing the phosphite, phosphonite, and phosphorane linkages may readily be prepared. A comparison has been made of the resistance of these polymers and of the corresponding polycarbonates, polysulfonates, and polyesters to various bases and to ferric chloride solutions.

Solution polymerizations of epoxytetrahydrophthalic anhydride and its utilization in various epoxy systems

AbstractSolution polymerization of epoxytetrahydrophthalic anhydride (ETHPA) has been thoroughly studied by using numerous solvents and catalysts. Products have been obtained in high yields, particularly when triethanolamine was the catalyst. This suggests that this catalyst should be considered for further applications utilizing ETHPA. However, the solution polymerization method cannot be used alone to define the effects of various catalysts on standard nonsolvated resin systems, because polymerization is greatly affected not only by the addition of solvent but also by the type of solvent. In addition, the action of the catalyst seems to depend greatly upon what solvent is employed. The reason for this dependence has not been established. The effects of the addition and reaction of ETHPA with commercial epoxy resin formulations have been investigated by means of heat distortion tests and differential thermal analyses. In most cases, although a moderate improvement was found in the thermal properties of the resins, occasional excellent results were obtained. A 10°C. increase in HDT is observed with a 2 wt.‐% addition of ETHPA for bisphenol A epoxy resin–bicyclic anhydride mixture. The degree of elevation of Tg and HDT with the addition of ETHPA obviously depends not only on the composition of the resin system but also on its cure temperature. A good correlation occurs between heat‐distortion temperatures and glass transition temperatures. Some few anomalous data, however, are found which point to the fact that further investigation is required before HDT and Tg can be interchanged without prior evidence of a definite relationship.

23. Plumbing

The cured condensed polynuclear aromatic (COPNA) resin has excellent thermal stability and self-lubricating property which is popular for friction materials. However the cured resin has brittleness and poorly molding process due to its high cross-linking density. In this paper, the allyl-COPNA-BMI copolymer resin is prepared via a solution polymerization method, its structure, and its mechanical and tribological properties are investigated with FT-IR, SEM, TGA techniques. The copolymer anti-friction and anti-wear behaviors are tuned by varying the N,N’-4,4’-diphenylmethane-bismaleimide(BMI) monomer loading. The mechanical properties of the copolymer is the best when the BMI loading is 20 wt% upon these results. The tensile and impact strength of the copolymer/BMI 20 wt% is 12 MPa and 13.9 MPa, respectively. The lowest friction coefficient of copolymer/BMI 30wt% is 0.27, and its abrasion rate is 0.601510-6mm3/Nm. The initial thermal decomposition temperature of the copolymer/BMI 40wt% is 400 oC and 46.5 wt% of char residue ratio at 642 oC. The copolymer resins exhibit good thermal stability, abrasive resistance and mechanical properties compared to the pure COPNA.

Osmotic pressure measurements of ethyl acrylate polymers. I. Dependence of molecular weight on conversion

AbstractBy employing the solution polymerization method, ethyl acrylate was readily polymerized, giving a product soluble in a number of organic solvents. By using benzene as the solvent, polymers of exceptionally high molecular weights were produced. The polymer samples were obtained by precipitation after the polymerization had proceeded for various periods of time. The slopes of the osmotic pressure curves were substantially constant for all the polymers. It is concluded that chain transfer to polymer during the polymerization process is insignificant and that the ethyl acrylate polymers do not contain any branched sites. It can be inferred from these data that the insolubility of ethyl polyacrylates frequently encountered is predominantly due to the extremely high molecular weights of the polymers.