Synthesis and characterization of negative‐type polyamic acid ester with 1‐methacryloyloxy‐2‐propanoate group

A negative‐type photosensitive polyamic acid (PAA) was synthesized from cyclobutane‐1,2,3,4‐tetracarboxylic dianhydride and 2‐(methacryloyloxy)ethyl 3,5‐diaminobenzoate in N‐methyl‐2‐pyrrolidinone. Glycidyl methacrylate was added into the PAA solution to yield a photosensitive PAA ester (PAE) by the ring‐opening esterification reaction of the carboxylic acid group in the PAA and glycidyl methacrylate. Esterification reactions were conducted with varying reaction temperatures and times. The typical PAE (PAE‐C3) with a degree of esterification of 20% was used for a photosensitivity study. We investigated the effects of the postexposure baking temperature, amount of photoinitiator, and exposure dose on the photosensitivity of PAE‐C3. Furthermore, a photolithography evaluation was conducted on PAE‐C3 in the presence of 1‐[4‐(phenylthio)phenyl]‐2‐(O‐benzoyloxime)‐1,2‐octanedione as a photoinitiator using a mercury lamp at a 365‐nm wavelength. The resolution of the film with 2.0‐μm thickness was about 8 μm. PAE‐C3 cured at 250°C for 60 min was stable up to around 310°C in a nitrogen atmosphere. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2252–2258, 2006     

Atom transfer radical polymerization of (R)‐2‐methacryloyloxy‐2′‐methoxy‐1,1′‐binaphthalene

Atom transfer radical polymerization (ATRP) of (R)‐2‐methacryloyloxy‐2′‐methoxy‐1,1′‐binaphthalene ((R)‐MAMBN) mediated by different amine ligands, copper(I) chloride and ethyl 2‐bromopropionate in different solvents, and reverse ATRP of (R)‐MAMBN were studied. It was shown that optically active polymers were obtained, with poor control of the molecular weights, and low polydispersities. Specific rotation of the polymers increased with increasing molecular weights. By comparison with (R)‐MAMBN, poly((R)‐MAMBN)s exhibits higher specific rotation and a positive Cotton effect. Copyright © 2003 Society of Chemical Industry     

Soluble and light‐colored polyimides from 2,3,2′,3′‐oxydiphthalic anhydride and aromatic diamines

A series of polyimides were prepared from 2,3,2′,3′‐oxydiphthalic anhydride (3,3′‐ODPA) with various aromatic diamines via three different synthetic procedures. The one‐step and two‐step methods with the thermal imidization of poly(amic acids) (PAAs) yielded polyimides with a relatively low inherent viscosity; these produced brittle films. The polyimides prepared by the two‐step method via the chemical imidization of PAA precursors exhibited a higher inherent viscosity and afforded tough and creaseable films. All the 3,3′‐ODPA based polyimides had a significantly higher solubility than the corresponding polyimides from 3,4,3′,4′‐oxydiphthalic anhydride. The films cast from 3,3′‐ODPA polyimides also showed high optical transparencies and less color, with an ultraviolet–visible absorption edge of 370–397 nm and low yellowness index values of 11.3–29.8. These polyimides exhibited glass‐transition temperatures in the range 211–289°C and showed no significant decomposition below 500°C under nitrogen or air atmospheres. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1352–1360, 2005     

Inhibition of calcium oxalate monohydrate by poly(acrylic acid)s with different end groups

Water‐soluble low molecular weight polymers are known to affect the crystal habit of scale‐forming minerals and their rates of deposition. Poly(acrylic acid) (PAA) and poly(maleic acid) are commonly used to control scale formation in sugar mill evaporators. Calcium oxalate (both mono‐ and dihydrate) forms the bulk of the hard intractable scale found in Australian sugar mills, causing efficiency losses of significant economic importance. In this work, the formation of calcium oxalate monohydrate in a synthetic juice solution was investigated in the presence of PAAs of varying molecular weights and end‐group functionality and a strong dependency on both of these factors was observed. Terminal functionality was controlled using three chain‐transfer agents (CTA): thioethanol, thioglycolic acid, and dodecanthiol. Effectiveness of inhibition varied with CTA in the order thioethanol ～ thioglycolic acid > dodecanthiol for all molecular weights. This suggests that polymer end groups play a role in scale inhibition. The polymers that were prepared with dodecanthiol accelerated rather than inhibited calcium oxalate formation, implying a different mode of action on calcium oxalate crystallization. Consistent with previous reports for other scales, the calcium oxalate inhibition tests show optimum effectiveness for PAAs of molecular weight 2000–4000. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2035–2041, 2004     

Synthesis and properties of novel crosslinkable second‐order nonlinear optical polymers based on 2,3,4,5,6‐pentafluorostyrene

Two crosslinkable second‐order nonlinear optical polymers were prepared by copolymerization of 2,3,4,5,6‐pentafluorostyrene, styrene (St), glycidyl methacrylate (GMA) and 1‐(4‐nitrophenyl)‐2‐(4‐{[2‐(methacryloyloxy) ethyl] ethylamino}‐phenyl) diazene (DR1M) via the sealed‐tube reaction technique. These polymers were characterized using ¹H, ¹³C and ¹⁹F NMR spectroscopy, gel permeation chromatography (GPC), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The crosslinkable polymers have high molecular weights, good organosolubility, excellent film‐forming properties and high glass transition (106–110 °C) and thermal decomposition temperatures (290–350 °C) after being crosslinked. Furthermore, the polymer films possess not only high values (12–16 pm V^?1) of electro‐optical coefficient (r₃₃) at 1.3 µm wavelength but also low optical loss (1.7 dB cm^?1) at 1.55 µm wavelength, which is of interest for applications in electro‐optical devices. Copyright © 2004 Society of Chemical Industry     

Molecular weight controlled poly(amic acid) resins end‐capped with phenylethynyl groups for manufacturing advanced polyimide films

To investigate the effect of reactive end‐capping groups on film‐forming quality and processability, a series of molecular weight‐controlled aromatic poly(amic acid) (PAA) resins functionalized with phenylethynyl end groups were prepared via the polycondensation of 3,3′,4,4′‐biphenyltetracarboxylic dianhydride (BPDA), para ‐phenylenediamine (PDA), and 4‐phenylethynyl phthalic anhydride (PEPA) served as molecular‐weight‐controlling and reactive end capping agent. The PAA resins with relatively high concentrations endow enhanced wetting/spreading ability to form PAA gel films by solution‐cast method which were thermally converted to the fully‐cured polyimide (PI) films. The mechanical and thermal properties of PI films were investigated as a function of PAA molecular weights (M_n ) and thermal‐curing parameters. Mechanical property, dimensional stability and heat resistance of the fully‐cured PI films with PAA M_n > 20 ×10³ g mol^?1 are found to be better than that of their unreactive phthalic end‐capped counterparts. The covalent incorporation of chain‐extension structures in the backbones, induced by thermal curing of phenylethynyl groups, might facilitate yielding a higher degree of polymer chain order and consequently improved resistance strength and elongation at break to tensile plastic deformation. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 45168.     

Effect of poly(acrylic acid) end‐group functionality on inhibition of calcium oxalate crystal growth

A number of series of poly(acrylic acids) (PAA) of differing end‐groups and molecular weights prepared using atom transfer radical polymerization were used as inhibitors for the crystallization of calcium oxalate at 23 and 80°C. As measured by turbidimetry and conductivity and as expected from previous reports, all PAA series were most effective for inhibition of crystallization at molecular weights of 1500–4000. However, the extent of inhibition was in general strongly dependent on the hydrophobicity and molecular weight of the end‐group. These results may be explicable in terms of adsorption/desorption of PAA to growth sites on crystallites. The overall effectiveness of the series didn't follow a simple trend with end‐group hydrophobicity, suggesting self‐assembly behavior or a balance between adsorption and desorption rates to crystallite surfaces may be critical in the mechanism of inhibition of calcium oxalate crystallization. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Synthesis of amphiphilic poly(methyl methacrylate)‐block‐poly(methacrylic acid) diblock copolymers by atom transfer radical polymerization

Atom transfer radical polymerization (ATRP) of 1‐(butoxy)ethyl methacrylate (BEMA) was carried out using CuBr/2,2′‐bipyridyl complex as catalyst and 2‐bromo‐2‐methyl‐propionic acid ester as initiator. The number average molecular weight of the obtained polymers increased with monomer conversion, and molecular weight distributions were unimodal throughout the reaction and shifted toward higher molecular weights. Using poly(methyl methacrylate) (PMMA) with a bromine atom at the chain end, which was prepared by ATRP, as the macro‐initiator, a diblock copolymer PMMA‐block‐poly [1‐(butoxy)ethyl methacrylate] (PMMA‐b‐PBEMA) has been synthesized by means of ATRP of BEMA. The amphiphilic diblock copolymer PMMA‐block‐poly(methacrylic acid) can be further obtained very easily by hydrolysis of PMMA‐b‐PBEMA under mild acidic conditions. The molecular weight and the structure of the above‐mentioned polymers were characterized with gel permeation chromatography, infrared spectroscopy and nuclear magnetic resonance. Copyright © 2005 Society of Chemical Industry     

Immobilization of 2,5‐dimethyl‐4‐benzoyl‐oxypiperidine succinate over polyacrylic acid (PAA) gels. I. Study of interaction between linear and network PAA with succinate of 2,5‐dimethyl‐4‐benzoyl‐oxypiperidine

The interaction of water‐soluble and crosslinked polyacrylic acid (PAA) with a medicinal compound (MC) of 2,5‐dimethyl‐4‐benzoyl‐oxypiperidine succinate was investigated. By methods of potentiometry, viscosimetry, and equilibrium swelling it was confirmed that the interaction of linear and network PAA with MC proceeds with complex formation. The degree of complex formation depends on the effect of pH, MC concentration, and degree of polyacid crosslinking. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1183–1186, 2005     

Emulsion copolymerization of vinyl acetate and 2‐ethyl hexyl acrylate using nonionic emulsifiers in loop reactor

Batch emulsion copolymerization of vinyl acetate and 2‐ethyl hexyl acrylate (VAc/2EHA = 90 : 10) was initiated by the thermal initiators ammonium persulfate and potassium persulfate at 70°C in the presence of nonylphenol ethoxylates with varying chain lengths and poly(vinyl alcohol). VAc–2EHA copolymer latexes were synthesized as two different series in a loop reactor. The first series was initiated by ammonium persulfate, and the second series was initiated by potassium persulfate. The influence of the counterions or initiators and chain lengths of a nonionic emulsifier on the properties of VAc–2EHA copolymer latexes were determined by measuring the viscosities, weight‐average molecular weights, number‐average molecular weights, molecular weight distribution, and surface tension of latexes to air. The results for the copolymer latexes indicated that some of their physicochemical properties increased with increasing chain length of the nonionic emulsifier, but some of them followed a different trend for the two initiators. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1380–1384, 2005     

Studies on poly(8‐hydroxy‐4‐azoquinolinephenylmethacrylate) and its metal complexes

8‐Hydroxy‐4‐azoquinolinephenylmethacrylate (8H4AQPMA) was prepared and polymerized in ethyl methyl ketone (EMK) at 65°C using benzoyl peroxide as free radical initiator. Poly(8‐hydroxy‐4‐azoquinolinephenylmethacrylate) poly(8H4AQPMA) was characterized by infrared and nuclear magnetic resonance techniques. The molecular weight of the polymer was determined by gel permeation chromatography. Cu(II) and Ni(II) complexes of poly(8H4AQPMA) were prepared. Elemental analysis of polychelates suggests that the metal‐ligand ratio is about 1 : 2. The polychelates were further characterized by infrared spectra, X‐ray diffraction, spectral studies, and magnetic moments. Thermal analyses of the polymer and polychelates were carried out in air. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1516–1522, 2006     

Development of potentially biocompatible hydrogels with cylindrical pores prepared from polyvinyl alcohol and low‐molecular weight polyacrylic acid

In the present work, blend hydrogels from PVA and two different low PAA molecular weights, Mw 1800 g/mol and 5000 g/mol were prepared through the freezing thawing (F‐T) physical crosslinking method. The obtained materials were fully characterized by means of scanning electron microscopy (SEM) in order to analyze their morphology, gel fraction (GF) to determine the crosslinking degree and Fourier transformed infrared spectroscopy (FTIR) to analyze the PVA‐PAA interactions. Thermal characterizations [thermogravimetric analysis (TGA) and dynamic scanning calorimetry (DSC)] were conducted to study the relevant thermal characteristics. Sorption tests at different pH values (4 and 7) obtained from different aqueous systems were also inquired. The effects of PAA contents (between 1 and 5 wt%) and Mw of the used PAA on the hydrogel final properties were analyzed and related to the most probably PVA‐PAA interactions. POLYM. ENG. SCI., 59:1479–1488 2019. © 2019 Society of Plastics Engineers     

Poly(2‐(methacryloyloxy) ethyl phosphorylcholine)‐functionalized multi‐walled carbon nanotubes: Preparation,characterization, solubility,and effects on blood coagulation

Water‐soluble multi‐walled carbon nanotubes (MWNTs) were prepared via surface‐initiated atom transfer radical polymerization (ATRP) of 2‐(methacryloyloxy) ethyl phosphorylcholine (MPC) from carbon nanotubes (CNTs). The success of the surface functionalization of MWNTs with poly(2‐(methacryloyloxy) ethyl phosphorylcholine) (pMPC) was ascertained using fourier transform infrared spectrophotometry (FTIR), thermogravimetric analysis (TGA), hydrogen nuclear magnetic resonance (¹H‐NMR), and transmission electron microscopy (TEM). Different from the results of the previous work, in our work, we demonstrate that the amount of pMPC on CNTs can be easily regulated by ATRP approach. In addition, from TGA results, a linear relationship between the weight loss fraction of MWNT‐pMPC and the weight of MPC fed and as high as 48.1% weight loss of MWNT‐pMPC (MWNTs grafted by pMPC) are observed. Through TEM, the core‐shell structure of MWNT‐pMPC is clearly observed, which is also different from the previous report. The pMPC‐modified MWNTs are highly soluble, which can also resist pH and saline concentration changes and remain stable in physiological environment. PMPC‐modified MWNT does not significantly affect the blood coagulation as demonstrated in plasma recalcification time (PRT) test. These highly soluble MWNTs are expected to enable their wide use in biomedical areas. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Synthesis and characterization of poly(amide–imide)s and their precursors as materials for membranes

Water soluble diamine amic acids (DAAs) were synthesized by reacting aliphatic diamines with pyromellitic dianhydride. Poly(amide–amic acid)s (PAAs) were prepared by interfacial polycondensation of DAAs in aqueous sodium hydroxide solution with isophthaloyl chloride in dichloromethane. Poly(amide–imide)s (PAIs) containing alternating (amide–amide)–(imide–imide) sequences were obtained by thermal cycloimidization of the PAA films at 175°C for 4 h in a forced air woven. The PAIs were readily soluble in polar aprotic solvents such as dimethylformamide, dimethylacetamide, dimethylsulfoxide, and N‐methyl‐2‐pyrrolidone. The inherent viscosities of the polymers are in the range of 0.97–1.7 dL/g. The polymers were characterized by IR, ¹H nuclear magnetic resonance (NMR), and thermogravimetric analysis (TGA). Thin film composite membranes containing PAA ultrathin barrier layer were prepared by in situ interfacial polycondensation of DAA in water with trimesoyl chloride or isophthaloyl chloride in hexane on the surface of a porous polysulfone membrane. The membranes were characterized for water permeability and for the separation of NaCl and Na₂SO₄. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 75: 1721–1727, 2000     

Preparation and application of sulfonated poly(1‐octene‐co‐styrene)

In this article, 1‐octene and styrene was copolymerized by the supported catalyst (TiCl₄/ID/MgCl₂). Subsequently, by sulfonation reaction, sulfonated poly(1‐octene‐co‐styrene)s which were amphiphilic copolymers were prepared. The copolymerization behavior between 1‐octene and styrene is moderate ideal behavior. Copolymers prepared by this catalyst contain appreciable amounts of both 1‐octene and styrene. Increase in the feed ratio of styrene/1‐octene leads to increase in styrene content in copolymer and decrease in molecular weight. As the polymerization temperature increases, the styrene content in the copolymers increases, however, the molecular weight decreases. Hydrogen is an efficient regulator to lower the molecular weights of poly(1‐octene‐co‐styrene)s. The sulfonation degree of the sulfonated poly(1‐octene‐co‐styrene)s increased as the styrene content in copolymer increased or the molecular weight decreased. Thirty‐six hour is long enough for sulfonation reaction. The sulfonated poly(1‐octene‐co‐styrene)s can be used as effective and durable modifying agent to improve the wettability of polyethylene film and have potential application in emulsified fuels and for the stabilization of dispersions. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Synthesis of well‐defined glycoconjugate polyacrylamides via preactivated polymers prepared by ATRP

Poly(N‐acryloxysuccinimide) (polyNAS) with narrow molecular weight distributions (MWD) applicable for the preparation of well‐defined glycoconjugate polyacrylamides were successfully prepared by atom transfer radical polymerization (ATRP). The structures of polyNAS were characterized by ¹H‐NMR and GPC. GPC results showed that the molecular weight polydispersity indices (PDI) range from 1.17 to 1.29. The molecular weights could be calculated based on ¹H‐NMR results but GPC results of polyNAS by using 0.01M LiBr/DMF did not give accurate molecular weights, probably because of the complex interaction in the system. The effects of free N‐hydroxysuccimide produced in the polymerization processes on the free‐radical concentrations and apparent initiation efficiencies of ATRP were discussed. Well‐defined glycoconjugate polyacrylamides (i.e., with narrow molecular weight distributions and designed glycoconjugate degrees) were prepared by substituting N‐oxysuccimide units with galactosamine followed by reaction of ethanolamine. The galactose conjugate degrees were determined by ¹H‐NMR and the total substitutions of N‐oxysuccimides were verified by ¹H‐NMR and FTIR. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 189–194, 2005     

A mucoadhesive polymer prepared by template polymerization of acrylic acid in the presence of poly(vinyl alcohol) for mucosal drug delivery

The interpolymer complexes composed of PVA and PAA were prepared by template polymerization of acrylic acid in the presence of PVA with different molecular weights and degrees of saponification. The carbonyl absorption band of the PAA in the PAA/PVA interpolymer complexes was shifted to a lower wavenumber due to H‐bonding between the carboxyl group of PAA and the hydroxyl group of PVA. The swelling ratio and the degree of dissolution of the PVA/PAA interpolymer complexes were dependent on the pH of the medium, the molecular weight, and the degree of saponification of the PVA. The release rate of a model drug, lidocaine, from the complexes decreased with increasing degree of saponification of the PVA due to the lower swelling degree of the complex. The adhesive force of the PVA/PAA interpolymer complexes with a plastic plate (poly propylene) was stronger than that of the commercial Carbopol 971P. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 327–331, 2004     

Improving properties of superabsorbent composite induced by using alkaline protease hydrolyzed‐sericin (APh‐sericin)

A series of superabsorbent polymer composites based on sericin hydrolyzed with alkaline protease (AP) were prepared by grafting with acrylic acid (AA) and acrylamide (AM). The properties of the superabsorbent polymers (SAP) by using hydrolyzed sericin with different amount of alkaline protease (nAPh‐sericin) were compared. It was found that the polymer prepared from 5APh‐sericin (the mass ratio of AP to sericin was 5.0 mg g⁻¹) showed the highest graft percentage and water absorbency, this phenomenon may be attributed to the change of molecular weight of resulting sericin molecules. The molecular structure of the grafted polymers was proved by thermal gravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR) measurements. Comparing with PAA‐AM (poly AA‐co‐AM) and 0APh‐sericin/PAA‐AM polymer, 5APh‐sericin/PAA‐AM polymer had the most excellent water retention capacity and enzyme degradability. The morphological features of the polymers with different drying methods were evidenced by SEM images. The water absorbencies of 5APh‐sericin/PAA‐AM polymer prepared with freeze‐drying were 896 g g⁻¹ in deionized water, 424 g g⁻¹ in tap water, and 83 g g⁻¹ in 0.9 wt% aqueous NaCl solution. POLYM. COMPOS., 35:509–515, 2014. © 2013 Society of Plastics Engineers     

Effect of the composition profile of 2‐ethyl hexyl acrylate/methyl methacrylate latex particles on adhesion

The adhesive properties (tack, shear, and peel) of 2‐ethyl hexyl acrylate/methyl methacrylate copolymer latex particles of different composition profiles (constant, positive, and negative gradients) but similar molecular weight distributions were studied. The composition profile had a strong effect on tack in the region of low molecular weights (weight‐average molecular weight ≤ 100,000 g/mol), but this effect was less important for higher molecular weights. No effect of the composition profile on shear or peel was observed for low‐molecular‐weight latices; nevertheless, for higher molecular weights (400,000 g/mol), resistance to shear strongly increased as heterogeneity increased, and resistance to peel was higher for gradient profiles. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1258–1265, 2001     

Synthesis and properties of polystyrene–clay nanocomposites via in situ intercalative polymerization

Organophilic montmorillonite (MMT) was prepared by ion exchange between Na⁺ ions in the clay and twin benzyldimethyloctadecylammonium bromine cations in an aqueous medium. The organophilic MMT particles were easily dispersed and swollen in styrene monomer. Polystyrene–MMT nanocomposites were prepared by the free‐radical polymerization of styrene containing dispersed clay. The intercalation spacing in the nanocomposites and the degree of dispersion of these composites were investigated with X‐ray diffraction and transmission electron microscopy, respectively. The nanocomposites had higher weight‐average molecular weights, lower glass‐transition temperatures, and better thermal stability (the decomposition temperature was improved by ca. 70°C) than the virgin polystyrene. The rheological behavior of the polystyrene–MMT nanocomposites was also studied. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 201–207, 2005