Graft polymers from poly(vinyl chloride) and chlorinated rubber

Graft polymers from poly(vinyl chloride) (PVC) and chlorinated rubber (CIR) with side chains of poly(methyl methacrylate) (PMMA), poly(methyl acrylate) (PMA), or poly(ethyl methacrylate) (PEMA) were synthesized. For this purpose, a vinyl monomer was polymerized in the presence of small quantities of PVC or CIR with benzoyl peroxide as catalyst. The graft polymers were separated from both homopolymers by precipitation with methanol from methyl ethyl ketone solutions of the reaction products and the grafting efficiency was calculated. The graft polymers were characterized by infrared spectra, elemental analysis, NMR, and osmometric or light-scattering determinations. From the results it is concluded that the PVC or CIR molecules contain side chains of PMMA, PMA, or PEMA. The graft polymers showed higher molecular weights, and the values of second virial coefficient for these polymers were much different from those of the starting polymers.     

Linear polymers of allyl acrylate and allyl methacrylate

Allyl acrylate and allyl methacrylate were polymerized by anionic initiators to soluble linear polymers containing allyl groups in the pendant side chains. The pendant unpolymerized allyl groups of the resulting linear poly(allyl acrylates) were shown to be present by: (1) the disappearance of the acrylyl and methacrylyl double bond absorptions in the infrared spectra in the conversions of monomers to polymers; (2) postbromination of the allyl bonds in the linear polymer; (3) the disappearance of the allyl groups absorptions in the infrared spectra of the brominated linear polymers; and (4) the thermal- and radical-initiated crosslinking of the linear polymers through the allyl groups. Allyl acrylate and allyl methacrylate show great reluctance to copolymerize with styrene under anionic initiation, but copolymerize readily with methyl methacrylate and acrylonitrile. Block copolymers were prepared by reacting allyl methacrylate with preformed polystyrene and poly(methyl methacrylate) anions. The linear polymers and copolymers of allyl acrylate may be classified as “self-reactive” polymers which yield thermosetting polymers. Bromination of the linear polymers offers a convenient method of producing self-extinguishing polymers.     

Interaction of inorganic salts with polar polymers. II. Infrared studies of polymer–inorganic nitrate systems

Certain inorganic nitrate salts are quite soluble in the polymers studied, namely, cellulose acetate, poly(vinyl acetate), poly(vinyl alcohol), poly(methyl methacrylate), and poly(methyl acrylate). Large effects upon the glass-transition temperature were observed in those systems where the transition could be readily measured. Large shifts in the infrared spectra of both the inorganic nitrate salts and in the polymer carbonyl and ester ether frequencies have been observed. These observations have been interpreted in terms of complex formation between these polymers and salts in the solid state. The proposed structure of the complex explains the nature of the infrared shifts both for the nitrate salts and the polymers as well as explaining the concentration effects observed. Effects of the solvating environment upon the salt and polymer spectra remain unexplained. The large glass-transition effects are a result of the degree of solubility of the salts in the polymers and the interactions between them. However, the reason why, in some cases, the change in the transition temperature as a function of concentration goes through a maximum is unclear.     

Theoretical determination of the infrared spectra of amorphous polymers

The simple procedure of calculating the infrared spectra of polymers is presented. It is based on selecting the relevant, medium-size representative fragments of a polymer, for which the vibrational frequencies are computed within the harmonic approximation, in conjunction with the multiparameter scaling techniques. Scaling is necessary to predict the reliable fundamentals, which, along with the calculated intensities and properly chosen band widths, reproduce the observed band shapes with high accuracy. Applications to the three polymers: poly(methyl methacrylate), poly(vinyl acetate), and poly(isopropenyl acetate) are presented. The simulated spectra are in good agreement with the experiment. The assignment of bands is reported. The obtained results indicate strong delocalization of the vibrational modes within polymers, which is in accord with the most recent experimental finding [Macromolecules2008, 41, 2494-2501]. Good agreement between the observed and the calculated spectra of deuterated PMMA confirms the correctness of our approach. The preliminary results obtained for the highly irregular macromolecular compound (vinyl-functionalized silica) are also shown.     

Post-lactonization of vinyl polymers containing pendent ester and hydroxymethyl groups

Copolymers of methyl methacrylate with methyl and ethyl α-hydroxymethylacrylate and with α-hydroxymethylstyrene have been prepared with free-radical initiators at temperatures below 80°C. At higher reaction temperatures or under extrusion conditions, alcohol was eliminated and the free hydroxyl content was greatly decreased. All evidence indicates the formation of six-membered lactone groups in this post-polymerization reaction: direct evidence for their formation is lacking, however, since neither infrared nor nuclear magnetic resonance spectra could be used to detect lactonization in this system. The loss of activity from ¹⁴C ester-labeled methyl methacrylate copolymer on heating could be correlated with the extent of lactonization. The degree of lactonization is relatively less with copolymers containing higher amounts of hydroxymethyl groups. The resulting polymers exhibit higher heat distortion temperatures and decreased impact resistance when compared to poly(methyl methacrylate). Attempts were made to incorporate similar lactone structures by cyclocopolymerization with methyl methacrylate of α-methacryloxymethylstyrene or ethyl α-methacryloxymethylacrylate, but only crosslinked polymers or polymers with pendent unsaturation were found.     

Pyrolysis/chemical ionization mass spectrometry of polymers

Pyrolysis/mass spectrometric studies have been made on polystyrene, poly(vinyl chloride), and poly(methyl methacrylate) with electron ionization (EI) and chemical ionization (CI) mass spectrometry and a variable temperature probe for direct insertion into the source of the mass spectrometer. Similar results obtained with EI and CI mass spectrometry are in agreement with previous experiments. Advantages of the simplification of spectra in the CI made, as well as the advantages of using both techniques for identification of pyrolysis products, are discussed.     

Synthesis,Characterization of Modified Graphene Oxide/Poly(methyl methacrylate) Composites

Graphene oxide was prepared by improving Hummers method and then modified by 4,4′-oxydianiline to get aminated graphene oxide, which was used to construct redox initiator system with dibenzoyl peroxide for synthesis of poly(methyl methacrylate) grafted to graphene oxide by in situ polymerization. Nanocomposites used grafted polymer as fillers with loadings from 0.5 to 1.0 wt % of poly(methyl methacrylate) were obtained by solution blending. The structures, properties and morphology of graphene oxide, grafted poly(methyl methacrylate) and composites are characterized by Fourier transform infrared spectroscopy, X-ray diffraction, Raman spectra, scanning electron microscopy, thermogravimetric analysis, dynamic mechanical thermal analysis and bacterial adhesion examination respectively. The initial decomposition temperature and the glass transition temperature of the nanocomposites are improved by addition of grafted poly(methyl methacrylate). Furthermore, there is a significant enhancement of the decreasing of the surface bacterial adhesion of prepared nanocomposites.     

Synthesis and characterization of two new aryl cyclobutyl ketoethyl methacrylate monomers and their polymers

Two new methacrylate monomers, 2‐[3‐(6‐tetralino)‐3‐methylcyclobutyl]‐2‐ketoethyl methacrylate (TKEMA) and 2‐(3‐mesityl‐3‐methylcyclobutyl)‐2‐ketoethyl methacrylate (MKEMA), were obtained from the reaction of 1‐chloroacetyl‐3‐methyl‐3‐arylcyclobutane with sodium methacrylate. The oxime and hydrazone derivatives of poly(TKEMA) and poly(MKEMA) were prepared with hydroxylamine and 2,4‐dinitrophenyl hydrazine. Poly(TKEMA) and poly(MKEMA), their oxime and hydrazone derivatives, and the monomers were characterized with Fourier transform infrared and NMR techniques. The glass‐transition temperatures and thermal stability of the polymers and their oxime and hydrazone derivatives were compared. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 4167–4173, 2001     

Desorption electrospray ionisation mass spectrometry and tandem mass spectrometry of low molecular weight synthetic polymers

A range of low molecular weight synthetic polymers has been characterised by means of desorption electrospray ionisation (DESI) combined with both mass spectrometry (MS) and tandem mass spectrometry (MS/MS). Accurate mass experiments were used to aid the structural determination of some of the oligomeric materials. The polymers analysed were poly(ethylene glycol) (PEG), polypropylene glycol (PPG), poly(methyl methacrylate) (PMMA) and poly(alpha-methyl styrene). An application of the technique for characterisation of a polymer used as part of an active ingredient in a pharmaceutical tablet is described. The mass spectra and tandem mass spectra of all of the polymers were obtained in seconds, indicating the sensitivity of the technique.     

Polymerization of adsorbed monolayers. III. Preliminary structure studies in dilute solution of the insertion polymers

Insertion poly(methyl acrylate) and poly(methyl methacrylate) were prepared from monomers adsorbed in monolayers on the surface of montmorillonite clay, both in the presence and in the absence of bifunctional crosslinkers (ethylene glycol dimethacrylate and tetramethylene glycol dimethacrylate). The insertion poly(methyl acrylate) and the crosslinked insertion poly(methyl methacrylate) and dilute-solution properties quite different from conventional polymers of these monomers, the differences including high light-scattering molecular weights combined with low viscosities, low values of the second virial coefficient, unusually large variations of the Huggins' constant k′ with the time-temperature history of the solutions, and low sedimentation velocities. These properties suggest that the insertion polymers have compact structures and are consistent with the postulate of sheetlike macromolecules. The dilute-solution properties of insertion poly(methyl methacrylate) made without crosslinker, unlike those of similarly prepared poly(methyl acrylate), were similar to those of conventional poly(methyl methacrylate). This difference in behavior is attributed to the different tendencies of the two monomers to undergo branching or crosslinking during radical polymerization.     

Structure of water incorporated in sulfobetaine polymer films as studied by ATR-FTIR

The structure and hydrogen bonding of water in the vicinity of a thin film of a sulfobetaine copolymer (poly[(N,N-dimethyl-N-(3-sulfopropyl)-3'-methacrylamidopropanaminium inner salt)-ran-(butyl methacrylate)], poly(SPB-r-BMA)), were analyzed with band shapes of O-H stretching of attenuated total reflection infrared (ATR-IR) spectra. The copolymer could be cast as a thin film, of approximate thickness 10 microm, on a ZnSe crystal for the ATR-IR spectroscopy. At an early stage of sorption of water into the polymer film, the O-H stretching band of the IR spectra for the water incorporated in the film was similar to that for free water. This is consistent with the tendency for another zwitterionic polymeric material, poly[(2-methacryloyloxyethylphosphorylcholine)-ran-(butyl methacrylate)] (poly(MPC-r-BMA). It is, however, contradictory to the drastic change in the O-H stretching band for water incorporated into films of polymers such as poly(2-hydroxyethyl methacrylate), poly(methyl methacrylate) and poly(butyl methacrylate). These results suggest that polymers with a zwitterionic structure do not significantly disturb the hydrogen bonding between water molecules incorporated in the thin films. The investigation into the blood-compatibility of both the poly(SPB-r-BMA) and the poly(MPC-r-BMA) films indicate a definite correlation between the blood-compatibility of the polymers and the lack of effect of the polymeric materials on the structure of the incorporated water.     

Time-lag focusing and cation attachment in the analysis of synthetic polymers by matrix-assisted laser desorption/ionization-time-of-flight-mass spectrometry

Ultraviolet matrix-assisted laser desorption/ionization-mass spectrometry has been employed with time-lag focusing to explore its utility for the characterization of synthetic polymers with broad distributions. Mixtures of five polymer standards with narrow molecular weight distributions were analyzed. The spectra were found to be broadly those expected for three different types of polymer systems—poly(styrene), poly(methyl methacrylate), and poly(ethylene glycol)—when equimass mixtures were used. Large changes in the apparent molecular weight distribution of poly(ethylene terephthalate) were observed when the cation was varied. The shift in the envelope was found to be related to the size and the ability of the oligomers to solvate the cation.     

Mechanism of generation of photoelastic birefringence in methacrylate polymers for optical devices

We clarified the birefringence properties of poly(methyl methacrylate), poly(ethyl methacrylate), poly(isobutyl methacrylate), poly(cyclohexyl methacrylate), poly(isopropyl methacrylate), and poly(tert‐butyl methacrylate). We demonstrated that the conformational change in polymer molecules that causes orientational birefringence differs from that causing photoelastic birefringence. Orientational birefringence depends mainly on the orientation of the main chains of the methacrylate polymers above T_g. On the other hand, photoelastic birefringence in elastic deformation below T_g depends mainly on the orientation of the side chains while the main chains are scarcely oriented. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 2029–2037, 2010     

Mechanism of fracture in glassy polymers. II. Survey of crazing response during crack propagation in several polymers

Of nine glassy polymers so far investigated, eight yield evidence that fracture propagation involves the formation and breaking of craze material. All eight produce fracture surfaces exhibiting interference colors to one extent or another and even the colorless areas cause low angle x-ray scattering. Ranked in terms of decreasing ease of colored surface formation, these polymers are poly(methyl methacrylate), poly(ethyl methacrylate), polystyrene, acrylonitrile—styrene copolymer, poly-α-methylstyrene, poly(vinyl acetate), a polyhydroxy ether, and polycarbonate. Only rigid poly(vinyl chloride) has failed to show evidence of precrack craze formation.     

Miscible blends of amorphous polymers

Thirty-five polymethacrylate/chlorinated polymer blends were investigated by differential scanning calorimetry. Poly(ethyl), poly(n-propyl), poly(n-butyl), and poly(n-amyl methacrylate)s were found to be miscible with poly(vinyl chloride) (PVC), chlorinated PVC, and Saran, but immiscible with a chlorinated polyethylene containing 48% chlorine. Poly(methyl) (PMMA), poly(n-hexyl) (PHMA), and poly(n-lauryl methacrylate)s were found to be immiscible with the same chlorinated polymers, except the PMMA/PVC, PMMA/Saran, and PHMA/Saran blends, which were miscible. A high chlorine content of the chlorinated polymer and an optimum CH₂/COO ratio of the polymethacrylate are required to obtain miscibility. However, poly(methyl), poly(ethyl), poly(n-butyl), and poly(n-octadecyl acrylate)s were found to be immiscible with the same chlorinated polymers, except with Saran, indicating a much greater miscibility of the polymethacrylates with the chlorinated polymers as compared with the polyacrylates.     

Correlation between the structure of water in the vicinity of carboxybetaine polymers and their blood-compatibility

The structure and hydrogen bonding of water in the vicinity of carboxybetaine homopolymer (poly[1-carboxy-N,N-dimethyl-N-(2'-methacryloyloxyethyl)methanaminium inner salt] (PolyCMB), and a random copolymer of CMB and n-butyl methacrylate, Poly(CMB-r-BMA), with various molecular weights were analyzed in their aqueous solutions and thin film with contours of O-H stretching of Raman and attenuated total reflection infrared (ATR-IR) spectra, respectively. The relative intensity of the collective band (C value) corresponding to a long-range coupling of O-H stretchings of the Raman spectra for aqueous solution of Poly(CMB-r-BMA) was very close to that for pure water, which is in contrast with the smaller C value in aqueous solution of ordinary polyelectrolytes. The number of hydrogen bonds collapsed by the presence of one monomer residue (N(corr) value) of PolyCMB and Poly(CMB-r-BMA) (CMB, 45 mol %) (M(w), 1.14 x 10(4) and 1.78 x 10(4), respectively) could be calculated from the C value. The N(corr) values were much smaller than those for ordinary polyelectrolytes and close to those for nonionic water-soluble polymers such as poly(ethylene glycol) and poly(N-vinylpyrrolidone). Furthermore, a water-insoluble Poly(CMB-r-BMA) with a large BMA content (M(w) = 347 kD, CMB 27 mol %) could be cast as a thin film (thickness, ca. 10 microm) on a ZnSe crystal for the ATR-IR analyses. At an early stage of sorption of water into the Poly(CMB-r-BMA) film, the O-H stretching band of IR spectra for the water incorporated in the film was similar to that for free water, which is in contrast with the drastic change in the O-H stretching band of water incorporated in polymer films such as poly(methyl methacrylate) (PMMA) and poly(n-butyl methacrylate) (PBMA). The theoretical vibrational frequency for water molecules hydrating a betaine molecule calculated by using a density functional method supported the experimental results. The adhesion of human platelets to Poly(CMB-r-BMA) films was much less than that to PMMA and PBMA. With an increase in the content of CMB residue, the number of platelets adhered to the Poly(CMB-r-BMA) film drastically decreased and then gradually increased, probably due to the increase in the roughness of the film surface. These results suggest that the carboxybetaine monomer residues with a zwitterionic structure do not significantly disturb the hydrogen bonding between water molecules in both aqueous solution and thin film systems, resulting in the excellent blood-compatibility of the carboxybetaine polymers.     

Homogeneous and multiphase poly(methyl methacrylate) graft polymers via the macromonomer method

Anionic and group transfer polymerization processes were used to synthesize controlled molecular weight methacryloyloxy functionalized poly(dimethylsiloxane) and poly(methyl methacrylate) macromonomers having a narrow molecular weight distribution and high percent functionality. These macromonomers were anionically copolymerized with methyl methacrylate (MMA) to afford poly(methyl methacrylate)-graft-poly(methyl methacrylate) (PMMA-g-PMMA) and poly(methyl methacrylate)-graft-poly(dimethylsiloxane) (PMMA-g-PDMS) polymers having not only narrow molecular weight distribution graft parts but also backbone parts. The PMMA-g-PDMS system was fractionated using supercritical chlorodifluoromethane to determine its chemical composition distribution (CCD). The CCD for the PMMA-g-PDMS copolymerized in a living manner was substantially more narrow than the free radically copolymerized material. The PMMA-g-PMMA system was used to study the dilute solution properties of branched homopolymers. The appropriateness of the universal calibration gel permeation chromatography (GPC) method for branched systems exhibiting long chain branching was reaffirmed.     

Constant loss in Brillouin spectra of polymers

The polarized (VV) and depolarized (VH) light scattering spectra of polyisobutylene, poly(methyl methacrylate), and glycerol were measured in the gigahertz frequency range at temperatures below and above the glass transition. Both VV and VH spectra exhibit a significant constant loss contribution that appears as a frequency‐independent imaginary part of the susceptibility spectrum. Existence of the frequency‐independent susceptibility in VV spectra below the Brillouin lines suggests that the constant loss also appears in mechanical relaxation in the gigahertz frequency range. Intensity of the constant loss increases strongly with temperature. Analysis of the spectra and literature data suggests that the constant loss can be general for many glass‐forming systems, but it is hidden in many cases by other relaxation contributions. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 40: 201–209, 2002     

Dielectric relaxation studies of some linear crosslinked and branched polymers

Dielectric loss measurements are reported for polystyrene, crosslinked polystyrene, polyacrylamide, branched polyacrylamide, and poly(methyl methacrylate) at 1 and 10 kHz f over the temperature range ?85 to +100°C. Crosslinking and branching have a pronounced effect on the dielectric relaxation spectra of polymers. The methods of preparation of these polymers and their viscosity molecular weight data are also reported.     

ESCA study of the surface photo-oxidation of some non-aromatic polymers

Changes in the surface composition and structure of a number of non-aromatic polymers subjected to ultraviolet irradiation in oxygen (～ 1 atm., 20°C) have been studied. No changes in surface composition were detected after photo-oxidation of poly(vinylidene fluoride) (12 h of irradiation), low density polyethylene (7·5 h) or high density polyethylene (22·3 h). This reflects the absence in these polymers of an efficient ultraviolet absorber to initiate the photo-oxidation. The surfaces of poly(methyl methacrylate) and nylon 66 show an increase in oxygen content following irradiation. In these polymers this added oxygen is present principally as carboxyl groups and, in the case of poly(methyl methacrylate), as carbonyl groups. In nylon, there is no evidence for changes in the amide group and no oxidation of the nitrogen is detected.