The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
We carry out simultaneous mechanical and IR-thermal-imaging based temperature measurements of SBR melts during uniaxial extension in order to delineate the nature of the observed mechanical responses. Using the first law of thermodynamics, we evaluate the enthalpy change h1 associated with the temperature rise in the extending melt, estimate the heat loss to the surrounding, and conclude that there...
Betaine ester-shell functionalized hyperbranched polyethylenimines (BEHPEI) were synthesized by Menschutkin reaction between per-N-methylated polyethylenimine (MeHPEI) and alkyl bromoacetate. BEHPEI could play dual antimicrobial roles that were, the betaine ester-shell acted as contact-based antibacterial polycations and the drug-loaded BEHPEI could controllably release the drugs due to the cleavage...
To improve the antifouling property and biocompatibility for polyacrylonitrile-based asymmetric membranes, phospholipid moieties were directly anchored on the poly(acrylonitrile-co-2-hydroxyethyl methacrylate) (PANCHEMA) membrane surface through the reaction of hydroxyl groups and 2-chloro-2-oxo-1,3,2-dioxaphospholane (COP) followed by the ring-opening of COP with trimethylamine. Fourier transform...
Poly(acrylonitrile-co-N-vinyl-2-pyrrolidone)s (PANCNVP) were synthesized by water-phase precipitation copolymerization (WPPCP) with sodium chlorate–sodium metabisulfite as an oxidant/reducer initiator system. The copolymers were also synthesized by a solution copolymerization (SCP) initiated with azobis(isobutyronitrile) for comparison. Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic...
A series of well-defined ABA triblock copolymers of poly(methyl acrylate)-polystyrene-poly(methyl acrylate) (PMA-b-PS-b-PMA) with different molecular weights were synthesized using Cl-PS-Cl as macroinitiator, CuCl/N,N,N′,N″,N″-pentamethyldiethylenetriamine (PMDETA) as catalyst system via atom transfer radical polymerization (ATRP). Amphiphilic triblock copolymer poly(potassium acrylate)-polystyrene-poly(potassium...
The multiple melting behavior of poly(ethylene terephthalate) (PET) homopolymers of different molecular weights and its cyclohexylene dimethylene (PET/CT) copolymers was studied by time-resolved simultaneous small-angle X-ray scattering/wide-angle X-ray scattering diffraction and differential scanning calorimetry techniques using a heating rate of 2 o C/min after isothermal crystallization...
The influence of nanodispersed montmorillonite layers and process history on the crystal structure of nylon 6 between room temperature and melting is examined with simultaneous small- and wide-angle X-ray scattering and modulated differential scanning calorimetry. For the examined process history, nylon 6 exhibits predominantly α-phase behavior from room temperature to melting, with a gradual shift...
The isothermal crystallization behavior of absorbable dyed and undyed PGA-co-PLA copolymers was investigated by time-resolved simultaneous small-angle X-ray scattering (SAXS) and wide-angle X-ray diffraction (WAXD) methods with synchrotron radiation. The morphological parameters extracted from time-resolved SAXS profiles show that long period and lamellar thickness decrease slightly after primary...
The transformation of mesomorphic phase to α-monoclinic crystal phase in quenched isotactic polypropylene has been investigated by TEM, DSC and time-resolved SAXS and WAXD methods. It is found that even though the initial appearance of the cluster structure in mesomorphic i-PP seems to support the model of a multi-step process for polymer crystallization, results indicate that the transformation is...
Isothermal melt crystallization in poly(butylene terephthalate) (PBT) homopolymers and glass-fiber-filled composite was studied by time-resolved simultaneous small- and wide-angle X-ray scattering (SWAXS) methods using synchrotron radiation. During primary crystallization, both average long period and lamellar thickness exhibit a significant decrease. During secondary crystallization, the long period...
We discuss the kinetics of order-order and order-disorder transitions in weakly segregated diblock copolymers. A theory is developed based on the anisotropic fluctuations in the ordered phases. These fluctuations play two crucial roles: first, they determine the stability limit of the initial structure and, second, they are responsible for the emergence of new structures, whether these are the final...
The toughness of PP/EPDM blends was measured over a wide range of temperature (25-132°C) and composition (0-26 wt% EPDM). It was found that increasing temperature and decreasing interparticle distance have equivalent effects on the brittle-tough transition of toughening PP with EPDM, and the shift factor increases with increasing temperature. A correlation was also found between temperature and...
Blends of nylon-6 and epoxidised ethylene propylene diene (eEPDM) rubber were prepared through reactive mixing. It is found that the toughness of nylon-6 can be much improved by this method, and that the particle size of eEPDM is much smaller than that of unexpoxidised EPDM (uEPDM) rubber in a nylon-6 matrix. This indicates that the epoxy group in eEPDM could react with a nylon-6 end group to form...
A super-tough polycarbonate (PC) blend was obtained by using epoxidized ethylene propylene diene (eEPDM) rubber as modifier. The notched Izod impact strength of PC/eEPDM (96/4) blend shows a great improvement, with a value about 25 times of that of pure PC. Finely and homogeneously dispersed rubber particles (0.2-0.8 μm) in the PC matrix indicated good adhesion between the eEPDM rubber phase and...
Irradiation can be applied to crosslink the dispersed elastomer phase to increase the modulus and decrease the voiding ability of the elastomer, which results in increasing critical brittle-tough transition elastomer content at constant temperature. The experimental results show that at 25°C the critical elastomer content of EPDM shifts to higher composition (shift of about 4 wt%) for PBT/EPDM blends...
In this paper, unepoxidized ethylene propylene diene rubber (uEPDM) was first epoxidized with formic acid and H 2 O 2 , and then the epoxidized ethylene propylene diene rubber (eEPDM) was melt-mixed with PBT resin in a Brabender-like apparatus. Toughening of PBT matrix was achieved by this method. The dispersion of rubber particles and phase structure of the blends were also observed...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.