1,721,025 research outputs found
Design of innovative macromolecules and molecules as additives for controlling properties and performances of lubrificants for automotives engines
No full textOne-step functionalization and reactive blending of polyolefin/polyamide mixtures (EPM/PA6)
No full textDiethyl maleate, maleic anhydride and dicumyl peroxide in different ratios were directly added to molten polymeric mixtures based on
ethylene-co-propylene (EPM) and polyamide 6 (PA6) to perform in one-step the functional groups grafting and branched copolymer formation
necessary to obtain compatibilized products.
The characterization of the blends by selective solvent extraction and IR and NMR analysis of the various fractions allowed to evidence the
occurrence of maleate grafting on both EPM and PA6 as well as the formation of graft copolymers at the interface. The effect of the reactions on
phase morphology development and thermal properties was evaluated by SEM and DSC analysis respectively in order to investigate the
compatibilization extent in comparison with the conventional two-steps procedure. Besides tests about mechanical properties of samples produced
by the extrusion were carried out
Reactive processing with functionalized polyolefins for the reuse of post-consumer polyamides and polyesters
No full textPolymers from Fossil and Renewable Resources. Scientific and Technological Comparison of Plastic Properties
No full textThe book describes the development and commercialization of materials with viscoelastic properties, placing particular emphasis on the scientific and technological differences between plastics and bioplastics. The authors explain how to handle each of the two types of materials and determine the comparative environmental impact of the material life-cycle. The practical values of the overlapping aspects of the two types of materials from technical properties to eco-compatibility are also discusse
Free radical grafting of diethylmaleate to polyamides in the melt during reactive processing with polyolefin
No full textEffect of structure of Functionalizing Molecules on the Inter-macromolecular Reactions and Blending of Poly(ethylene-co-propylene) (EPM) with Poly(6-aminohexanoic Acid) (PA6)
No full textTwo different functionalizing systems, i.e., monohexadecyl maleate (=hexadecyl hydrogen (2Z)-but-
2-enedioate) in the presence of dicumyl peroxide (=bis(1-methyl-1-phenylethyl) peroxide) or 4-carboxybenzenesulfonazide
(=4-(azidosulfonyl)benzoic acid), were used in distinct experiments to perform
in a one-step procedure the formation of a EPM–PA6 graft copolymer, necessary to obtain a compatibilized
blend, from a molten mixture of ethylene–propylene copolymer (EPM) and polyamide 6 (PA6).
The characterization of the graft polymer by selective solvent extraction of the blends and the subsequent
IR and NMR analysis of the various fractions established the occurrence of functionalization reactions
preferentially onto the polyolefin with both reagents. Also the formation in good yield of graft copolymers
at the phases interface was observed. Moreover, the morphology and thermal characterizations
of the blends by means of SEM and DSC analyses were used to evaluate the compatibilization extent
in comparison with blends obtained by the conventional two-step procedure or by the one-step procedure
with commercial maleic acid derivatives
Preparation of phyllosilicates nanocomposites: from petrochemical to renewable thermoplastic matrices
No full textNanocomposites based on thermoplastic polymers and functional nanofiller for sensor applications
Full text linkThermoplastic polymers like polyolefins, polyesters, polyamide, and styrene polymers are the most representative commodity plastics thanks to their cost-efficient manufacturing processes, excellent thermomechanical properties and their good environmental compatibility, including easy recycling. In the last few decades much effort has been devoted worldwide to extend the applications of such materials by conferring on them new properties through mixing and blending with different additives. In this latter context, nanocomposites have recently offered new exciting possibilities. This review discusses the successful use of nanostructured dispersed substrates in designing new stimuli-responsive nanocomposites; in particular, it provides an updated description of the synthetic routes to prepare nanostructured systems having the typical properties of thermoplastic polymers (continuous matrix), but showing enhanced optical, conductive, and thermal features dependent on the dispersion topology. The controlled nanodispersion of functional labeled clays, noble metal nanoparticles and carbon nanotubes is here evidenced to play a key role in producing hybrid thermoplastic materials that have been used in the design of devices, such as NLO devices, chemiresistors, temperature and deformation sensors
Co-agent mediated functionalization of LDPE/iPP mixtures for compatibilization of WEEE-recovered polyvinylchloride
No full textMixtures of low density polyethylene/isotactic polypropylene (LDPE/iPP) 80/20 w/w were functionalized in the melt by using maleic anhydride (MAH) as the functionalizing agent, 2,5-bis(tert-butylperoxy)-2,5-dimethylhexane (L101) as the peroxide initiator and butyl 3-(2-furyl)propenoate (BFA) as a co-agent suitable to prevent the degradation of iPP and to promote inter-macromolecular reactions. The use of BFA was aimed at favouring the control of radical-induced side reactions and the formation of interfacial graft copolymers. The functionalization degree and the modification of macromolecular architecture, which were evaluated by selective solvent extractions combined with IR, DSC and SEM analyses, were modulated by varying the L101/MAH/BFA ratio in the feed. The optimized product in terms of functionalization degree value and processability was successfully tested as compatibilizer in a polyolefin/polyvinylchloride mixture, where the polyvinylchloride component resulted from the management of waste of electrical and electronic equipment (WEEE)
Polyolefins functionalized with maleic anhydride and with its high-boiling liquid esters, preparation thereof, and use as compatibilizers
No full textPolyolefins functionalized with maleic anhydride (I) and at least one of its high-boiling esters are prepd. in high yields, with high degrees of functionalization, without the prodn. of byproducts of crosslinking or degrdn. The process, which may be carried out either continuously or discontinuously, is characterized by the use of inorg. substances having a specific porosity, grain size, d. and humidity, as vehicles of the functionalizing monomers; the presence of maleic ester contributes to enhancing the reaction efficiency. Also described are a double-screw extruder for carrying out the process, and the use of products obtained as compatibilizing additives in adhesives and reinforcing polymers. Thus, a functionalizing mixt. of di-Et maleate 0.6, I 2, dicumyl peroxide 0.18 kg adsorbed on 0.35 kg hydrophobic silica (99% purity, av. particle size 5 μm, surface area 280 m2/g, water content 0.4 wt.%, bulk d. 0.185 g/cm3) and dild. with 2 kg powd. HDPE, and EPR CO 038 (28% propylene) were fed through an extruder at 5 and 175 kg/h, resp., giving MFI 0.65, Mw/Mn 3.0, I functionality 0.9%, and functional efficiency 82%, compared with 1.5, 3.4, 0.45, and 48, resp., without the di-Et maleate. A molding from a 65:35 mixt. of nylon 6 and the above functionalized EPR showed Izod impact strength 1020 J/m at 23° and 1016 J/m at -20°, compared with 34 and 29, resp., for nylon 6 alone, and 750 and 340, resp., for an 80:20 nylon 6-FM 1 (com. impact modifier of 0.9%-maleated ethylene-propene copolymer)
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