Structuring of polypropylene matrix in composites

Binarni kompoziti izotaktnog polipropilena (iPP) s talkom i wollastonitom modificirani s različitim elastomerima: (poli(stiren-bbutadien-b-stiren) (SBS), poli(stiren-b-etilen-co-propilen) (SEP), poli(stiren-b-etilen-co-butilen-b-stiren) (SEBS), SEBS kopolimer cijepljen s maleinskim anhidridom (SEBS-g-MA), etilen/propilen/dienski kaučuk (EPDM) i metalocenski kopolimeri polipropilena (mEPR)) pri definiranim različitim omjerima sadržaja proučavani su pomoću različitih mikroskopskih metoda (optička, SEM, TEM), rendgenskom difrakcijom pri velikom kutu (WAXD) i diferencijalnom pretražnom kalorimetrijom (DSC). Kompleksna istraživanja odnosa struktura-svojstvo uspoređivanjem ternarnih iPP kompozita sa sastavnim binarnim kompozitima i binarnim mješavinama pokazala su da različiti čimbenici djeluju na (re)strukturiranje kristalaste polipropilenske matrice tijekom kristalizacije i očvršćivanja (solidifikacije) tijekom priprave ploča izravnim prešanjem. Strukturna istraživanja usmjerena su na određivanja čimbenika koji utječu na rast kristalita i sferolita, faznu strukturu iPP kristalita, stupanj kristalnosti, orijentaciju čestica punila i iPP kristalita, faznu morfologiju čestica i sustava kompozita i sastavnih mješavina polipropilena. U međuigri ovih čimbenika koji sudjeluju u strukturiranju iPP matrice mogu se prepoznati slijedeći utjecajni faktori: (i) nukleacija sitnim dispergiranim česticama polimera i punila, (ii) orijentacija iPP kristalita i čestica punila, (iii) migracija/prijenos iPP lanaca iz otočića taljevine u rastuće lamele tijekom očvršćivanja, (iv) uklapanje (enkapsulacija) dispergiranih čestica i punila koja vodi do morfologije jezgra-ljuska, (v) steričkih faktora smetnji koje generiraju čestice punila i dispergirane čestice elastomera pri sferolitizaciji iPP matrice i (vi) moguća djelomična kokristalizacija u područjima iPP/metalocenski kopolimer polipropilena (iPP/mEPR).Binary isotactic polypropylene (iPP) composites with talc and wollastonite were modified with different elastomers: poly(styrene-bbutadiene-b-styrene) (SBS), poly(styrene-b-ethylene-co-propylene) (SEP), poly(styrene-b-ethylene-co-butylene-b-styrene) (SEBS), SEBS grafted with maleic anhydride (SEBS-g-MA), ethylene/propylene/diene terpolymer (EPDM), and propylene-based metallocene (mEPR) at different content ratios and studied by different microscopic techniques (optical, SEM, TEM), wide-angle X-ray diffraction (WAXD) and differential scanning calorimetry (DSC). Complex investigations of the structure-property relationships by comparison of ternary iPP composites with constitutive binary composites and binary blends showed that different factors affect (re)structuring of the semicrystalline polypropylene matrix during its crystallization and solidification during preparation by compression moulding. Structural investigations were focused on determination of influencing factors in crystallite and spherulite growth, phase structure of the iPP crystallites, degree of crystallinity, orientation of filler particles and iPP crystallite, structuring/spherulitization of the iPP matrix, and phase morphology of particles and polypropylene composite and constitutive blend systems. From the interplay of different factors in structuring of the iPP matrix the following influencing factors could be recognized: (i) nucleation by tiny dispersed particles of polymers and filler particles, (ii) orientation of the iPP crystallite and filler particles, (iii) migration/transferring of the iPP chains from melt islands to growing lamellae during solidification, (iv) encapsulation of dispersed/filler particles leading to core-shell morphology, (v) steric hindrance factors generated by filler and dispersed elastomer particles in the spherulitization of the iPP matrix, and (vi) possible partly co-crystallization in the iPP/propylene-based metallocene copolymer (iPP/mEPR) regions

Polypropylene Blends with m-EPR Copolymers: Mechanical and Rheological Properties

The effects of two metallocene ethylene-propylene-based elastomers (m-EPR1 and m-EPR2) differing in molecular mass and viscosity on mechanical, rheological and interfacial properties were compared. The m-EPR elastomers were added to iPP in 2.5, 5, 10, 15, and 20 vol.%. Torque values, elongation at break and impact strength measured of the iPP/m-EPR1 blends were higher than the iPP/m-EPR2 blends due to higher molten viscosity of m-EPR1 than m-EPR2 copolymer. Slight differences in Young moduli as well as in tensile strength at yield and at break might indicate that tensile properties of iPP/m-EPR blends were not significantly affected by difference in viscosity or molecular mass, miscibility and spherulite size. Optimization diagrams indicated the metallocene m-EPR copolymers are efficient impact modifiers for polypropylene and showed good balancing of mechanical properties in iPP/m-EPR blends

The influence of thermoplastic elastomers on morphological and mechanical properties of PP/talc composites

Recent investigations have shown that modification of polymer matrix with filler and elastomers significantly affects composite\u27s mechanical properties. Isotactic PP modified with either untreated or treated talc and either SEBS or SEBS-gMA were used in these investigations. Samples were prepared by melt-mixing in a Brabender kneading chamber and were compression molded into plates on a laboratory press. The composites were characterised by measuring mechanical properties (Young\u27s modulus, yield stress, notched impact strength) and by defining morphology. Binary sistems PP/talc and PP/elastomer containing up to 16 vol.% of talc and up to 10 vol.% of elastomer, as well as ternary PP/talc/elastomer composites with 12 vol.% talc were investigated. Ternary composite\u27s yield stress was also calculated by semiempirical equations. We have found out, that the use of treated modifiers (talc or elastomer) improves adhesion with matrix, which reflects on mechanical properties as better stress transfer.Novejše raziskave so pokazale, da lahko z modifikacijo polimerne matrike s polnilom in elastomerno fazo znatno vplivamo na mehanske lastnosti nastalega kompozita. V raziskavah smo uporabili izotaktični PP ter ga modificirali z neobdelanim oz. obdelanim talkom in SEBS oz. SEBS-gMA. Vzorce smo pripravili preko taline v Brabenderjevem gnetilniku in s stiskanjem v plošče na laboratorijski stiskalnici. Karakterizirali smo jih z merjenjem mehanskih lastnosti (Youngov modul, meja plastičnosti, zarezna udarna žilavost) in z opredelitvijo morfologije. Preučevali smo binarne sisteme PP/talk in PP/elastomer z vsebnostjo talka do 16 vol.% in do 10 vol.% elastomera, kakor tudi ternarne kompozite PP/talk/elastomer z 12 vol.% talka. Mejo plastičnosti ternarnih kompozitov smo določili še s polempiričnimi enačbami. Ugotovili smo, da uporaba obdelanih modifikatorjev (talka oz. elastomera) izboljša adhezijo z matriko, kar odseva na mehanskih lastnostih kot boljši prenos napetosti

Bioplin - trajnostni vir energije

In this paper, biogas as a sustainable energy source is examined from economic, environmental and socio-politic points of view. The pros and cons of biogas and the compatibility of biogas as a sustainable energy source within EU directions and goals were examined using a SWOT analysis. Because new technologies for the exploitation of biogas are being rapidly developed and improved, technologies for the exploitation of biogas are identified, analysed and crosscompared. New possibilities, potentials and options for the development of the biogas industry in Slovenia are presented, and the possibilities for biogas exploitation and biogas potential are examined. Measures for the faster and more efficient development of biogas industry and for encouraging biogas exploitation are proposed. Proposals are also made on the basis of comparison of current state of the biogas industry in Slovenia, with current state of the biogas industry in Austria (predominantly Styria) and Sweden (predominantly Östergötland County). Proven effective measures from Austria are analysed and the implementation of the most appropriate and effective measures from Austria is proposed.V prispevku preučujemo bioplin kot trajnostni vir energije iz ekonomskega, okoljskega in družbeno-političnega vidika. Prav tako preučujemo prednosti in slabosti bioplina s SWOT analizo in testiramo kompatibilnost bioplina, kot trajnostnega vira energije, z smernicami in cilji EU. Ker se nove tehnologije za koriščenje bioplina zelo hitro razvijajo in izboljšujejo, smo identificirali, analizirali in primerjali tehnologije za koriščenje bioplina. Dodatno predstavljamo nove možnosti in potenciale za razvoj industrije bioplina v Sloveniji. Preučene so možnosti za izkoriščanje bioplina in potencial bioplina v Sloveniji. Predlagani so tudi ukrepi za vzpodbujanje rabe bioplina ter za hitrejši in učinkovitejši razvoj industrije bioplina. Predlogi so podani na temelju primerjave stanja na področju bioplina v Sloveniji z stanjem, ukrepi in primeri dobre prakse iz Avstrije (pretežno Štajerske) in Švedske (pretežno okrožja Östergötland). Dokazano učinkovite in uspešne ukrepe iz Avstrije smo analizirali in predlagali njihovo implementacijo v slovenskem prostoru

Investigations of modified polypropylene and talc composites

V razvoju novih polimernih materialov zavzemajo pomembno mesto polimerni kompoziti, proizvedeni iz polipropilena (PP). Preučevali smo kompozite iz PP in talka, površinsko obdelanega z aminosilani, in polimernega modifikatorja. Kompoziti so vsebovali 12 vol.% obdelanega talka in do 10 vol.% blokkpolimerov poli-(stiren-b-etilen-co-butilen-b-stirena)(SEBS) različnih molskih mas, SEBS, grafitiranega z maleinanhidridom (SEBS-gMA), ali PP, grafitiranega z maleinanhidridom (PP-gMA). Vzorce smo pripravili preko taline v Brabenderjevem gnetilniku in s stiskanjem v plošče na laboratorijski stiskalnici. Kompozite PP/talk/SEBS-gMA in PP/talk/PP-gMA smo pripravili tudi pri različnih časih gnetenja. V delu so komentirani rezultati meritev predelovalnih lastnosti (torzijski moment mešanja), mehanskih lastnosti (natezne lastnosti, zarezna udarna žilavost) in študija morfologije v odvisnosti od sestave in tehnoloških pogojev priprave kompozitov.Polymer composites based on polypropylene (PP) play an important role in the development of new polymeric materials. Composites of PP, surface treated talc and polymer modifier were investigated. The composites contained 12 vol.% of treated talc and up to 10 vol.% of poly(styrene-b-ethylene-co-butylene-b-styrene) block copolymers (SEBS) of different molecular weights, SEBS grafted with maleic anhydride (SEB-gMA) or PP grafted with maleic anhydride (PP-gMA). Samples were prepared by melt-mixing in a Brabender kneading chamber and were compression molded into plates on a laboratory press. PP/talc/SEBS-gMA and PP/talc/PP-gMA composites were also prepared at different kneading durations. The results of measurement on processing properties (torque), mechanical properties (tensile properties, notched impact strength) and the study of morphology are commented in this article as a function of composition and technological conditions of composites preparation

Morphology of Polypropylene/Silica Nano-and Microcomposites

ABSTRACT: The aim of this study was to compare the effects of different silica grades on the structure and morphology of isotactic polypropylene (iPP)/silica composites to better understand their structure-property relationships. Isotactic polypropylene composites with 2, 4, 6, 8 vol % of added silica fillers differing in particle size (micro-vs. nanosilica) and surface modification (untreated vs. treated surface) were prepared by nonisothermal compression molding and characterized by different methods. The addition of all silica fillers grades to the iPP matrix significantly influenced the spherulitic morphology, while phase characteristics of the iPP matrix seemed to be unaffected. Surface modification of silica fillers exhibited stronger effects on spherulite size than size of silica particles. Nonpolar silica particles, more miscible or compatible with iPP chains than polar silica particles, enabled better spherulitic growth. The spherulite sizes tended to reach equal values at 8 vol % of added silicas showing that spherulite size became independent of filler concentration and surface modification above optimum filler concentration