Preparation of poly(divinylbenzene‐co‐N‐isopropylacrylamide) microspheres and their hydrogen‐bonding assembly behavior for raspberry‐like core‐corona polymer composite

Narrowdisperse poly(divinylbenzene‐co‐N‐isopropylacrylamide) (poly(DVB‐co‐NIPAM)) functional microspheres with the diameter in the range of 630 nm and 2.58 μm were prepared by distillation–precipitation polymerization in neat acetonitrile in the absence of any stabilizer. The effect of N‐isopropylacrylamide (NIPAM) ratio in the comonomer feed on the morphology of the resultant polymer particles was investigated in detail with divinylbenzene (DVB) as crosslinker and 2,2′‐azobisisobutyronitrile (AIBN) as initiator. The monodisperse poly(DVB‐co‐NIPAM) microspheres with NIPAM fraction of 20 wt % were selected for the preparation of raspberry‐like core‐corona polymer composite by the hydrogen‐bonding self‐assembly heterocoagulation with poly(ethyleneglycol dimethacrylate‐co‐acrylic acid) [poly(EGDMA‐co‐AA)] nanospheres. Both of the functional poly(DVB‐co‐NIPAM) microspheres and the core‐corona particles were characterized with scanning electron microscopy (SEM), Fourier transform infrared spectra (FTIR), and elemental analysis (EA). © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1350–1357, 2007     

Synthesis and characterization of novel oligomeric poly(styrene‐co‐acrylonitrile)–clay complexes

Oligomeric poly(styrene‐co‐acrylonitrile) quaternary ammonium salts were prepared through reactions of trimethylamine with corresponding poly(styrene–acrylonitrile–vinyl benzyl chloride)s, which were synthesized by the free‐radical polymerization of a mixture of styrene, acrylonitrile, and vinyl benzyl chloride. Then, oligomeric poly(styrene‐co‐acrylonitrile)‐modified clays were prepared through the cation exchange of the sodium ions in the clay with the corresponding poly(styrene‐co‐acrylonitrile) quaternary ammonium salts. The poly(styrene–acrylonitrile–vinyl benzyl chloride)s, poly(styrene‐co‐acrylonitrile) quaternary ammonium salts, and their clay complexes were characterized with infrared spectroscopy, gel permeation chromatography, thermogravimetric analysis, proton nuclear magnetic resonance, X‐ray diffraction, and transmission electron microscopy. X‐ray diffraction and transmission electron microscopy studies showed that these novel clay complexes were well intercalated. Furthermore, thermogravimetric analysis data indicated that this series of polymerically modified clays had high enough thermal stability for nanocomposites by melt blending. The thermal treatment of one of these novel clays at 250°C under nitrogen was also conducted. Solubility and infrared studies of this thermally treated clay complex revealed that a novel polyimine/enamine structure clay complex had been formed in the gallery of the clay. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Polymer nanocomposites containing carbon nanotubes and miscible polymer blends based on poly[ethylene‐co‐(acrylic acid)]

Four binary polymer blends containing poly [ethylene‐co‐(acrylic acid)] (PEAA) as one component, and poly(4‐vinyl phenol‐co‐2‐hydroxy ethyl methacrylate) (P4VPh‐co‐2HEMA) or poly(2‐ethyl‐2‐oxazoline) (PEOx) or poly(vinyl acetate‐co‐vinyl alcohol) (PVAc‐co‐VA) or poly (vinylpyrrolidone‐co‐vinyl acetate) (PVP‐co‐VAc) as the other component were prepared and used as a matrix of a series of composite materials. These binary mixtures were either partially or completely miscible within the composition range studied and were characterized by differential scanning calorimetry (DSC) and Fourier transformed infrared spectroscopy (FTIR). Carbon nanotubes (CNTs) were prepared by a thermal treatment of polyester synthesized through the chemical reaction between ethylene glycol and citric acid over an alumina boat. High resolution transmission electron microscopy (HRTEM) was used to characterize the synthesized CNTs. Films of composite materials containing CNTs were obtained after evaporation of the solvent used to prepare solutions of the four types of binary polymer blends. Young's moduli of the composites were obtained by thermomechanical analysis at room temperature. Only one glass transition temperature was detected for several compositions on both binary blends and the composite material matrices. Evidence of hydrogen bond formation was recorded for both miscible blends and composite materials. The degree of crystallinity and Young's moduli of the CNT‐polymer composites increased compared to the single polymer blends. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci 2008     

Synthesis of block copolymers via redox polymerization

Polymerization and copolymerization of vinyl monomers such as acrylamide, acrylonitrile, vinyl acetate, and acrylic acid with a redox system of Ce(IV) and organic reducing agents containing hydroxy groups were studied. The reducing compounds were poly(ethylene glycol)s, halogen‐containing polyols, and depolymerization products of poly(ethylene terephthalate). Copolymers of poly(ethylene glycol)s‐b‐polyacrylonitrile, poly(ethylene glycol)s‐b‐poly(acrylonitrile‐co‐vinyl acetate), poly(ethylene glycol)s‐b‐polyacrylamide, poly(ethylene glycol)s‐b‐poly(acrylamide‐co‐vinyl acetate), poly(1‐chloromethyl ethylene glycol)‐bpoly(acrylonitrile‐co‐vinyl acetate), and bis[poly(ethylene glycol terephthalate)]‐b‐poly(acrylonitrile‐co‐vinyl acetate) were produced. The yield of acrylamide polymerization and the molecular weight of the copolymer increased considerably if about 4% vinyl acetate was added into the acrylamide monomer. However, the molecular weight of the copolymer was decreased when 4% vinyl acetate was added into the acrylonitrile monomer. Physical properties such as solubility, water absorption, resistance to UV light, and viscosities of the copolymers were studied and their possible uses are discussed. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 1385–1395, 1999     

Effects of poly(vinyl acetate) and poly(vinyl chloride‐co‐vinyl acetate) low‐profile additives on properties of cured unsaturated polyester resins. II. glass‐transition temperatures and mechanical properties

Three series of self‐synthesized poly(vinyl acetate)‐based low‐profile additives (LPAs), including poly(vinyl acetate), poly(vinyl chloride‐co‐vinyl acetate), and poly(vinyl chloride‐co‐vinyl acetate‐co‐maleic anhydride), with different chemical structures and molecular weights were studied. Their effects on the glass‐transition temperatures and mechanical properties for thermoset polymer blends made from styrene, unsaturated polyester, and LPAs were investigated by an integrated approach of the static phase characteristics, cured sample morphology, reaction kinetics, and property measurements. Based on Takayanagi mechanical models, the factors that control the glass‐transition temperature in each phase region of the cured samples and the mechanical properties are discussed. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3347–3357, 2003     

Synthesis of poly[(2‐oxo‐1,3‐dioxolan‐4‐yl)methyl vinyl ether‐co‐N‐phenylmaleimide] and its miscibility in blends with styrene‐acrylonitrile or poly(vinyl chloride)

The aim of the study was to investigate the synthesis of a copolymer bearing cyclic carbonate and its miscibility with styrene/acrylonitrile copolymer (SAN) or poly(vinyl chloride) (PVC). (2‐Oxo‐1,3‐dioxolan‐4‐yl)methyl vinyl ether (OVE) as a monomer was synthesized from glycidyl vinyl ether and CO₂ using quaternary ammonium chloride salts as catalysts. The highest reaction rate was observed when tetraoctylammonium chloride (TOAC) was used as a catalyst. Even at the atmospheric pressure of CO₂, the yield of OVE using TOAC was above 80% after 6 h of reaction at 80°C. The copolymer of OVE and N‐phenylmaleimide (NPM) was prepared by radical copolymerization and was characterized by FTIR and ¹H‐NMR spectroscopies and differential scanning calorimetry (DSC). The monomer reactivity ratios were given as r₁ (OVE) = 0.53–0.57 and r₂ (NPM) = 2.23–2.24 in the copolymerization of OVE and NPM. The films of poly(OVE‐co‐NPM)/SAN and poly(OVE‐co‐NPM)/PVC blends were cast from N‐dimethylformamide. An optical clarity test and DSC analysis showed that poly(OVE‐co‐NPM)/SAN and poly(OVE‐co‐NPM)/PVC blends were both miscible over the whole composition range. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 1809–1815, 2000     

Poly(acrylamide‐co‐vinyl alcohol)—Superabsorbent materials reinforced by modified clay

A series of copolymeric superabsorbent materials comprising polyacrylamide (PAM), polyvinyl alcohol (PVA) reinforced with variable wt% of modified clay were prepared. The copolymer/clay composite was characterized by Fourier transformed infrared, transmission electron microscopy, and scanning electron microscopy. The water absorbencies of poly(acrylamide‐co‐vinyl alcohol)/clay composites were measured by calculating their percentage swelling ratio. The effects of copolymerization, type of clay, and clay content on the water absorbencies were studied. The swelling was measured in acidic, alkaline, and saline condition to ensure its versatility. The results indicated a remarkable increase in swelling ratio by incorporation of modified clay having higher hydrophilicity and optimum clay loading. The poly(acrylamide‐co‐vinyl alcohol)/clay composite hydrogel was found to have better re‐swelling ability and water retention capacity compared to the virgin copolymer. The substantial enhancement of swelling properties enables the superabsorbent poly(acrylamide‐co‐vinyl alcohol)/clay suitable for agricultural and horticultural application. POLYM. COMPOS., 34:1794–1800, 2013. © 2013 Society of Plastics Engineers     

Supramolecularly Mediated Robust,Anti‐Fatigue,and Strain‐Sensitive Macromolecular Microsphere Composite Hydrogels

Hydrogels are increasingly investigated and applied in flexible electronic devices, but their practical applications are often restricted by the poor mechanical and limited anti‐fatigue properties. This works reports an approach to robust, anti‐fatigue, and strain‐sensitive hydrogels by introducing macromolecular microsphere and mediating their supramolecular cross‐linking points. A model network composed of sulfonated polystyrene (SPS) microspheres and poly(acrylamide‐co‐acrylic acid)/Fe³⁺ (poly(Am‐co‐AA)/Fe³⁺) is investigated. The resulting composite hydrogels have high tensile strength (4.29 MPa) and anti‐fatigue property. More interestingly, such composite hydrogels have strain‐dependent conductivity and can be applied in robust flexible strain sensors for monitoring various human motions. Overall, the hydrogels developed herein not only help to understand the enhancing mechanism of composite hydrogels, but also offer alternative materials for fabricating robust electronic devices.     

Effects of poly(vinyl acetate) and poly(vinyl chloride‐ co‐vinyl acetate) low‐profile additives on properties of cured unsaturated polyester resins. I. Volume shrinkage characteristics and internal pigmentability

Three series of self‐synthesized poly(vinyl acetate)‐based low‐profile additives (LPAs) with different chemical structures and molecular weights, including poly(vinyl acetate), poly(vinyl chloride‐co‐vinyl acetate), and poly(vinyl chloride‐co‐vinyl acetate‐co‐maleic anhydride), were studied. Their effects on the volume shrinkage characteristics and internal pigmentability for low‐shrink unsaturated polyester (UP) resins during cure were investigated. The experimental results were examined with an integrated approach involving measurements of the static phase characteristics of the ternary styrene/UP/LPA system, the reaction kinetics, the cured sample morphology, and microvoid formation by using differential scanning calorimetry, scanning electron microscopy, optical microscopy, and image analysis. Based on the Takayanagi mechanical model, factors leading to both good volume shrinkage control and acceptable internal pigmentability for the molded parts were explored. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3336–3346, 2003     

Complexation of poly(dimethylsiloxane)/poly(methyl methacrylate‐co‐butyl acrylate‐co‐methacrylic acid) latex with poly(dimethylsiloxane)/poly(vinyl acetate‐co‐butyl acrylate) latex

Two latices—the poly(dimethylsiloxane) (PDMS)/poly(methyl methacrylate‐co‐butyl acrylate‐co‐methacrylic acid) system (PA latex) and the PDMS/poly(vinyl acetate‐co‐butyl acrylate) system (PB latex)—were prepared by seeded emulsion polymerization, and PA/PB complex latices were obtained through the interparticle complexation of the PA latex with the PB latex. In addition, for the further study of the interparticle complexation of the PA latex with the PB latex, copolymer latices [PDMS/methyl methacrylate‐co‐butyl acrylate‐co‐vinyl acetate‐co‐methacrylic acid) (PC)] were prepared according to the monomer recipe of the complex latices and the polymerization process of the component latices. The properties of the obtained polymer latices and complex latices were investigated with surface‐tension, contact‐angle, and viscosity measurements. The mechanical properties of the coatings obtained from the latices were investigated with tensile‐strength measurements. The results showed that, in comparison with the two component latices (PA latex and PB latex) and the corresponding copolymer latices (PC latices), the PA/PB complex latices had lower surface tension, lower viscosities, and better wettability to different substrates. The tensile strengths of the coatings obtained from the complex latices were higher than the tensile strengths of the coatings from the two component latices and copolymer latices. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2522–2527, 2004     

Effects of thermal imidization on mechanical properties of poly(amide‐co‐imide)/multiwalled carbon nanotube composite films

In this study, experimental and numerical studies were performed to investigate the relationship among the functionalization method, weight fraction of MWCNTs, thermal imidization cycle, and mechanical properties of various PAI/MWCNT composite films. Poly(amide‐co‐imide)/multiwalled carbon nanotube composite films were prepared by solution mixing and film casting. The effects of chemical functionalization and weight fraction of multiwalled carbon nanotubes on thermal imidization and mechanical properties were investigated through experimental and numerical studies. The time needed to achieve sufficient thermal imidization was reduced with increasing multiwalled carbon nanotube content when compared with that of a pure poly(amide‐co‐imide) film because multiwalled carbon nanotubes have a higher thermal conductivity than pure poly(amide‐co‐imide) resin. Mechanical properties of pure poly(amide‐co‐imide) and poly(amide‐co‐imide)/multiwalled carbon nanotube composite films were increased with increasing imidization time and were improved significantly in the case of the composite film filled with hydrogen peroxide treated multiwalled carbon nanotubes. Both the tensile strength and strain to failure of the multiwalled carbon nanotube filled poly(amide‐co‐imide) film were increased substantially because multiwalled carbon nanotube dispersion was improved and covalent bonding was formed between multiwalled carbon nanotubes and poly(amide‐co‐imide) molecules. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Gloss reduction and morphological properties of polycarbonate and poly(methyl methacrylate‐acrylonitrile‐butadiene‐styrene) blends with SAN‐co‐GMA as a reactive compatibilizer

The gloss properties of the polycarbonate (PC)/poly(methyl methacrylate‐acrylonitrile‐butadiene‐styrene) (MABS) blend with styrene‐acrylonitrile‐co‐glycidyl methacrylate (SAN‐co‐GMA) as a compatibilizing agent were investigated. For the PC/poly(MABS)/SAN‐co‐GMA (65/15/20, wt %) blend surface, the reduction of gloss level was observed most significantly when the GMA content was 0.1 wt %, compared with the blends with 0.05 wt % GMA or without GMA content. The gloss level of the PC/poly(MABS)/SAN‐co‐GMA (0.1 wt % GMA) blend surface was observed to be 35, which showed 65% lower than the PC/poly(MABS)/SAN‐co‐GMA blend without GMA content. The gloss reduction was most probably caused by the insoluble fractions of the PC/poly(MABS)/SAN‐co‐GMA blend that were formed by the reaction between the carboxylic acid group in poly(MABS) and epoxy group in SAN‐co‐GMA. The results of optical and transmission electron microscope analysis, spectroscopy study, and rheological properties supported the formation of insoluble structure of the PC/poly(MABS)/SAN‐co‐GMA blend when the GMA content was 0.1 wt %. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46450.     

Preparation and characterization of ceria nanoparticles supported on poly(4‐vinyl pyridine‐co‐divinyl benzene)

Formation of ceria nanoparticles in 2% divinyl benzene (dvb) crosslinked 4‐vinyl pyridine (4vp) polymer [poly(4vp‐co‐dvb)] microspheres was investigated. The polymer was prepared by free radical suspension polymerization method. Poly(4vp‐co‐dvb)/ceria nanocomposites were prepared by reacting CeCl₃·7H₂O and NaOH in the presence of poly(4vp‐co‐dvb) at room temperature in aqueous media. The mole ratio of the metal to polymer was varied from 2.5 to 10% with an increment of 2.5. The polymer and nanocomposities were characterized by various spectrochemical methods. The coordination of nitrogen atoms of the polymer with Ce(IV) of ceria (CeO₂) has been confirmed from X‐ray photoelectron spectroscopy (XPS). The method has yielded ceria nanoparticles in an average size of 15 nm according to transmission electron microscopy. Differential scanning calorimetry, thermogravimetric analysis, X‐ray diffractometry and XPS analysis with respect to mole percentage of ceria in the composite are discussed. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3439–3445, 2006     

Synthesis and antitumor activity of poly(3,4‐dihydro‐2H‐pyran‐co‐maleic anhydride‐co‐vinyl acetate)

The radical‐initiated terpolymerization of 3,4‐dihydro‐2H‐pyran (DHP), maleic anhydride (MA), and vinyl acetate (VA), which were used as a donor–acceptor–donor system, was carried out in methyl ethyl ketone in the presence of 2,2′‐azobisisobutyronitrile as an initiator at 65°C in a nitrogen atmosphere. The synthesis and characterization of binary and ternary copolymers, some kinetic parameters of terpolymerization, the terpolymer‐composition/thermal‐behavior relationship, and the antitumor activity of the synthesized polymers were examined. The polymerization of the DHP–MA–VA monomer system predominantly proceeded by the alternating terpolymerization mechanism. The in vitro cytotoxicities of poly(3,4‐dihydro‐2H‐pyran‐alt‐maleic anhydride) [poly(DHP‐alt‐MA)] and poly(3,4‐dihydro‐2H‐pyran‐co‐maleic anhydride‐co‐vinyl acetate) [poly(DHP‐co‐MA‐co‐VA)] were evaluated with Raji cells (human Burkitt lymphoma cell line). The antitumor activity of the prepared anion‐active poly(DHP‐alt‐MA) and poly(DHP‐co‐MA‐co‐VA) polymers were studied with methyl–thiazol–tetrazolium testing, and the 50% cytotoxic dose was calculated. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 2352–2359, 2005     

Synthesis and properties of silver nanoparticles in chitosan‐based thermosensitive semi‐interpenetrating hydrogels

In this article, thermosensitive poly(N‐isopropyl acrylamide‐co‐vinyl pyrrolidone)/chitosan [P(NIPAM‐co‐NVP)/CS] semi‐interpenetrating (semi‐IPN) hydrogels were prepared by redox‐polymerization using N,N‐methylenebisacrylamide as crosslinker and ammonium persulfate/N,N,N′,N′‐tetramethylethylenediamine as initiator. Highly stable and uniformly distributed Ag nanoparticles were prepared by using the semihydrogel networks as templates via in situ reduction of silver nitrate in the presence of sodium borohydride as a reducing agent. Introduction of CS improves the hydrogels swelling ratio (SR) and stabilizes the formed Ag nanoparticles in networks. Scanning electron microscopy and transmission electron microscopy revealed that Ag nanoparticles were well dispersed with diameters of 10 nm. The semi‐IPN hydrogel/Ag composites had higher SR and thermal stability than its corresponding semi‐IPN hydrogels. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Initiation of surface graft polymerization by ceric ions on polymer microspheres

The surface graft polymerization of acrylamide on poly(styrene‐co‐acrylonitrile) copolymer microspheres by the initiation of ceric ions was studied. The grafting was verified by IR spectra and X‐ray photoelectron spectroscopy measurements. The resultant microspheres with surface‐grafted polymer chains were employed in the preparation of polymer‐microsphere‐supported palladium composite particles. The composite particles were then studied by transmission electron microscopy and X‐ray diffraction. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 936–940, 2003     

Electrical actuation of ionic hydrogels based on polyvinyl alcohol grafted with poly(2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid‐co‐acrylonitrile) chains

Novel electrically conducting composite materials consisting of poly(pyrrole) (PPy) nanoparticles dispersed in a poly(vinyl alcohol)‐g‐poly(2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid‐co‐acrylonitrile) hydrogels were prepared within the polymer matrix by in situ polymerization of pyrrole. The conversion yield of pyrrole into PPy particles was determined gravimetrically while structural confirmation of the synthesized polymer was sought by Fourier Transform Infrared (FTIR) and UV‐visible spectroscopy. The morphology of PPy nanoparticles containing hydrogel matrix was investigated by Scanning Electron Microscopy (SEM) analysis. Electrical conductivity of nanocomposite hydrogels of different compositions was determined by LCR meter while electroactive behavior of nanocomposite hydrogels swollen in electrolyte solutions was investigated by effective bend angle measurements. POLYM. COMPOS., 2012. © 2011 Society of Plastics Engineers     

Phase‐separation prevention and performance improvement of poly(vinyl acetate)/TEOS hybrid using modified sol‐gel process

The formation of covalent bonds between silanols in copolymer and those in silica prevents organic–inorganic phase separation. Two series of hybrid composite materials, poly(vinyl acetate‐co‐vinyl trimethoxysilane)/TEOS and poly[vinyl acetate‐co‐3‐(trimethoxysilyl)propyl methacrylate]/TEOS, were fabricated using a modified sol‐gel process. The hybrids were transparent. Two kinds of silane coupling agents, vinyl trimethoxysilane (VTS) and 3‐(trimethoxysilyl)propyl methacrylate (γ‐MPS), were used to prevent macrophase separation through formation of covalent bonds. Thermal analysis showed that γ‐MPS was more effective than VTS for the formation of covalent bonds. Enhancement of thermal stability of the hybrids was investigated by thermogravimetric analysis. Photomicrographs of scanning electron microscopy and images of atomic force microscopy indicated that inorganic silica particles were homogeneously dispersed in less than 50 nm in organic matrix. The morphological properties of hybrids were strongly dependent on the organic–inorganic composition. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2310–2318, 2001     

Flurbiprofen axetil loaded coaxial electrospun poly(vinyl pyrrolidone)–nanopoly(lactic‐co‐glycolic acid) core–shell composite nanofibers: Preparation,characterization, and anti‐adhesion activity

Flurbiprofen axetil (FA)‐loaded coaxial electrospun poly(vinyl pyrrolidone) (PVP)–nanopoly(lactic‐co‐glycolic acid) core–shell composite nanofibers were successfully fabricated by a facile coaxial electrospinning, and an electrospun drug‐loaded system was formed for anti‐adhesion applications. The FA, which is a kind of lipid microsphere nonsteroidal anti‐inflammatory drug, was shown to be successfully adsorbed in the PVP, and the formed poly(lactic‐co‐glycolic acid) (PLGA)/PVP/FA composite nanofibers exhibited a uniform and smooth morphology. The cell viability assay and cell morphology observation revealed that the formed PLGA/PVP/FA composite nanofibers were cytocompatible. Importantly, the loaded FA within the PLGA/PVP coaxial nanofibers showed a sustained‐release profile and anti‐adhesion activity to inhibit the growth of the IEC‐6 and NIH3T3 model cells. With the significantly reduced burst‐release profile, good cytocompatibility, and anti‐adhesion activity, the developed PLGA/PVP/FA composite nanofibers were proposed to be a promising material in the fields of tissue engineering and pharmaceutical science. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41982.     

Self‐association through hydrogen bonding and sequence distribution in poly(vinyl acetate‐co‐vinyl alcohol) copolymers

Correlation between hydrogen‐bonding self‐association and sequence distribution in poly(vinyl acetate‐co‐vinyl alcohol) copolymers (ACA) with different degrees of basic hydrolysis and sequence distributions has been studied by thermal analysis and NMR spectroscopy. ¹³C NMR spectroscopy has also been used to elucidate the blocky nature, branching, and tacticity of the copolymers. Thermal analytical studies indicate that hydrogen bonding distribution in block alcohol and vinyl acetate copolymers strongly depend on the sequence distribution wherein hydroxyl–hydroxyl self‐association is preferred. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 72: 123–133, 1999