4-chloromethyl styrene (cms) was copolymerized with different monomers such as methyl methacrylate (mma), methyl acrylate (ma), 2-ethylhexyl acrylate (eha) by free radical polymerization method at 70 ±1°c using a,a'-azobis(isobutyronitrile) (aibn) as an initiator. the copolymer compositions were obtained using related 1hnmr spectra and the polydispersity of the copolymers were determined using ...

Films of chitosan and N,N,N-trimethylchitosan were cast from aqueous solutions. Chitosan was dissolved in 1% acetic acid while deionized water was the solvent for N,N,N-trimethylchitosan chloride. The resulting films presented different mechanical behaviors as evaluated by DMTA. The film of chitosan exhibited an elastic-type behavior while that of N,N,N-trimethylchitosan was typically viscous. ...

Films of EVOH copolymers, processed three times by twin-screw extrusion were prepared using a cast-film line. The variation on the melt flow rate (MFR) and rheological behaviour of the films were determined, as well as the thermal properties assessed by differential scanning calorimetry (DSC) and dynamic-mechanical thermal analysis (DMTA). As the results showed that the reprocessing induced an ...

The climatic cooling that began in the late middle Eocene and culminated Eocene-Oligocene transition meant major changes Palaeotheriidae (Perissodactyla, Mammalia) biodiversity Europe could have caused appearance of new dietary strategies. This work is first to study spatiotemporal response one palaeotheriid genus (Plagiolophus) environmental ecological using three proxies: hypsodonty, mesowear...

epoxy – polysulfide copolymers without or with low amounts of epoxy in their structure have poor mechanical properties in oxidative curing system.to strengthen the mechanical properties of polysulfide elastomer inclusion of epoxy resin (epon828) as hard segment was studied. ft-ir spectroscopy and rheometry were used to verify the formation of epoxy-polysulfide copolymer.  results obtained from ...

Serows and gorals (Bovidae, Caprinae) are emblematic antelopes distributed in Southeast Asia. They all nearly threaten or vulnerable species nowadays despite having a more widespread distribution during the Pleistocene. Fossils of three native caprine species, i.e., Sumatran serow Capricornis sumatraensis , Chinese goral Naemorhedus griseus Himalayan were recovered from four Pleistocene paleont...

Abstract The orthotropic and temperature-dependent nature of the mechanical properties wood is well recognized. However, past studies at elevated temperatures are either limited to below 200 °C or focus only on direction parallel grain. effect time-dependent pyrolysis during measurement often neglected. This paper presents a novel method for determining elastic modulus high thermal expansion co...