The effect of short polystyrene brushes grafted from graphene oxide on the behavior of miscible PMMA/SAN blends

A new concept of utilization of particle-polymer hybrids as multifunctional additives for polymer blends was introduced in this study. Graphene oxide particles with short densely grafted polystyrene brushes (GO-g-PS) were prepared by surface-initiated atom transfer radical polymerization (SI-ATRP). Melt rheology studies revealed that GO-g-PS suppressed the phase separation of miscible poly(methyl methacrylate)/poly(styrene-co-acrylonitrile) (PMMA/SAN) blends. The studies suggested specific interactions of GO-g-PS with the PMMA phase and this was confirmed based on calculations of activation energies of segmental relaxations by broadband dielectric spectroscopy (BDS). These unusual interactions of GO-g-PS with PMMA phase were assigned to the specific and precise architecture of the GO-g-PS particles as well as chemical nature of PS polymer brushes. The short chains of PMMA and PS provide miscibility originating from UCST behavior of PMMA/PS blend of short polymer chains. Additionally, BDS also revealed improved charge transport in PMMA/SAN blend in presence of GO-g-PS hybrid. © 2020 Elsevier LtdAction Austria - Slovakia, Co-operation in Science and Education program [56337]; National Science Centre, PolandNational Science Center, PolandNational Science Centre, Poland [UMO-2016/23/P/ST5/02131]; European Unions' Horizon 2020 research and innovation program under Marie Sklodowska-Curie grant [665778]; Research & Innovation Operational Programme - ERDF [313021T081]; project VEGAVedecka grantova agentura MSVVaS SR a SAV (VEGA) [2/0129/19]; Technology Agency of the CR [TN01000008]; Ministry of Education, Youth and Sports of the Czech Republic - DKRVO [RP/CPS/2020/003

Nanotechnology as potential method for recycling of PET bottles

Recycling of PET worldwide is not sufficient. This issue results from decreasing molecular weight due to thermal, mechanical and hydrolytic degradation during multiple processing of polymer. The viscosity (next processability) of material can be increased by preparation of nanocomposites (formation of physical network in the polymer/clay system). The improved processing and utility properties of recycled PET were analyzed by rheology, morphology and tensile tests

Nanokompozity typu recyklát PET/organo-jíl

The processable recycled PET/organo-clay nanocomposites were prepared via melt compounding method as a new possibility of recovery of the used PET bottles. XRD and rheological measurements revealed intercalation of polymer chains into the silicate gallery and significant increase of melt strength of the material, which result in improvement of processability of regranulate

Physical recycling of PET bottles - possibilities of the next aplications

The authors have assessed various sources of recycled PET (washed dry flakes, ground preforms etc.) using the proper methods (TG, viscometry, filtration test of the melt, DSC, ESM etc.). They have evaluated the most harmful impurities. The data presented could help those interested in the other potential applications of the recycled PET materials. This publication is one of the results based on the Grant sponsored by Czech Ministry of Industry and Trade "The new possibilities of the textile application of the recycled PET bottles"

PLA based bionanocomposites and their transport properties

This paper deals with the evaluation of gas transport properties of bionanocomposites based on polylactic acid 2003D (PLA). Montmorillonite based fillers, Cloisite® 10A, 20A, 30B and natural Cloisite® Na+, were incorporated into PLA polymer films. PLA/clay mixtures were produced by twin screw extruder ZSK-25. Further testing sheets were prepared from PLA/clay mixtures by Brabender Plasti-Corder equipped by flat die. The prepared composites were evaluated for water absorption, permeability of gases and water vapors. Further material morphology was assessed using X-ray diffraction as well as transmission electron microscopy. The best results achieved compositions with PLA/Cloisite10A and Cloisite 30B. © 2018 Author(s).TBU in Zlin RVOE; [63p24]; [66p21

Transport properties of poly(lactic acid)/clay nanocomposites

Poly(lactic acid) (PLA) is one of the most promising sustainable alternatives to petroleum-based polymers. One of the main applications is in the packaging industry. Therefore, this article deals with the evaluation of gas transport properties polylactic acid 2003D nanocomposite. Montmorillonite-based fillers, Cloisite® 10A, 20A, 30B and natural Cloisite® Na+, intended to enhance the transport properties, were incorporated into a series of PLA films. The influence of the additive on the transport properties was studied under the conditions of melt processing. Further material morphology was assessed using X-ray diffraction and transmission electron microscopy. The best results achieved compositions with PLA/Cloisite10A and Cloisite 30B with improvement more than 50%. POLYM. ENG. SCI., 2019. © 2019 Society of Plastics Engineers. © 2019 Society of Plastics EngineersAction 63p24; Action 66p21; TBU in Zlin RVO

Recycled poly(ethylene terephthalate) reinforced with basalt fibres: Rheology, structure, and utility properties

Použití recyklovaného polyetylentereftalátu (PET) jako matrice pro kompozity připravované kontinuálním mícháním je zajímavé jak environmentálního, tak i průmyslového hlediska. V naší práci byl pomocí reologie, diferenciální snímací kalorimetrie a tahových zkoušek sledován vyztužující efekt různého obsahu krátkých čedičových vláken a práškového mastku na recyklát PET. Kvalita zamíchání byla sledována pomocí snímací elektronové mikroskopie (SEM) a reologie tavenin. Zpracovatelské a užitné vlastnosti PET recyklátu se přidáním plniva zlepšily. Větší elasticita taveniny, mezifázová adheze a mechanické vlastnosti kompozitů byly v souladu se strukturou pozorovanou pomocí SEM.Utilization of recycled poly(ethylene terephthalate) (PET) as a matrix for composite materials prepared by continuous compounding is challenging from the environmental as well as industrial point of view. In our work, cut basalt fibers and talc powder of various compositions were used and their reinforcing effect on recycled PET was tested by rheology (Advanced Rheometric Expansion System), differential scanning calorimetry, and tensile experiments. The quality of filler dispersion in recycled PET matrix was investigated by scanning electron microscopy (SEM) and melt rheology. Processing and utility properties of composites were enhanced as compared with those of unfilled matrix. Higher melt elasticity, interfacial adhesion, and better mechanical performance of the composites were in a good agreement with the structure observed from SEM micrographs

Effect of glass fibers on rheology, mechanical properties of recycled thermal and PET

Byly připaveny kompozity na bázi PET a krátkých skleněných vláken mícháním taveniny PET recyklátu se skleněným vláknem (15, 20 a 30 hm.%). Stupeň zamíchání byl určen pomocí skenovací elektronové mikroskopie. Rotační reometrie byla použita k analýze vzájemné smykové pevnosti mezi PET taveninou a skleněnými vlákny.Kompozit se 30 % vláken vykázal střední plató 2. řádu u G?, čímž byla silná fázová interakce potvrzena. Výsledky z mechanických zkoušek byly v dobrém souladu se strukturními a reologickými měřeními. V porovnání s materiály připravenými v poloprovozních podmínkách vedla větší rychlost míchání při provozních podmínkách k nižší mezifázové adhezi a podobnému stupni zamíchání. Tepelné chování a množství krystalické fáze bylo analyzováno pomocí diferenciální snímací kalorimetrie.PET-glass fiber composites were prepared by melt mixing of recycled PET with chopped glass fibers (15, 20, and 30 wt%) and their degree of dispersion was assessed by scanning electron microscopy. Rotational rheometry was employed to analyze the interfacial shear strength between the fibers and polymer matrix in the molten state. The composite containing 30 wt% of glass fibers revealed a moderate G' secondary plateauhence strong fiber-matrix interactions were confirmed. Results of mechanical testing were in a good accordance with structural and rheological measurements. The higher rate of mixing under production-scale conditions resulted in lower fiber-matrix adhesion and in a similar level of fiber dispersion as compared to the same mixture compounded on pilot-plant scale. Thermal characterization of the composites was performed by differential scanning calorimetry and total crystalline fraction was analyzed

Recycled PET nanocomposites improved by silanization of organoclays

Recycled PET/organo-modified montmorillonite nanocomposites were prepared via melt compounding as a promising possibility of the used beverage bottles recovery. According to our previous work, the three suitable commercial organoclays Cloisite 25A, 10A, and 30B were additionally modified with [3-(glycidyloxy)propyl]trimethoxysilane, hexadecyltrimethoxysilane and (3-aminopropyl)trimethoxysilane. The selected organoclays were compounded in the concentration 5 wt % and their degree of intercalation/delamination was determined by wide-angle X-ray scattering and transmission electron microscopy. Modification of Cloisite 25A with [3-(glycidyloxy)propyl]trimethoxysilane increased homogeneity of silicate layers in recycled PET. Additional modification of Cloisite 10A and Cloisite 30B led to lower level of delamination concomitant with melt viscosity reduction. However, flow characteristics of all studied organoclay nanocomposites showed solid-like behavior at low frequencies. Silanization of commercial organoclays had remarkable impact on crystallinity and melt temperature decrease accompanied by faster formation of crystalline nuclei during injection molding. Thermogravimetric analysis showed enhancement of thermal stability of modified organoclays. The tensile tests confirmed significant increase of PET-R stiffness with organoclays loading and the system containing Cloisite 25A treated with [3-(glycidyloxy)propyl]trimethoxysilane revealed combination of high stiffness and extensibility, which could be utilized for production of high-performance materials by spinning, extrusion, and blow molding technologies. (C) 2007 Wiley Periodicals, Inc

Uplatnění preventivního přístupu k odpadovému hospodářství a navýšení aplikační hodnoty polymerů: Využití nanotechnologie pro nalezení efektivní metody recyklace PET lahví

Zpráva je rozdělena do několika částí: 1. Zaměření projektu (současná situace v oblasti recyklace PET lahví, charakterizace materiálu, recyklace PET a polymerní nanokompozity. 2. Použité metody hodnocení nanokompozitů (reologie taveniny nanokompozitu, WAXS - širokoúhlá rentgenová spektroskopie, TEM /SEM/ - transmisní (scanovací/ elektronová mikroskopie, DSC - diferenciální scanovací kalorimetrie, mechanické vlastnosti za působení jednoosého protažení). 3. Experimentální část (použité materiály, příprava nanokompozitu recyklovaný PET/jíl, morfologie připravených nanokompozitů, reologické charakteristiky, mechanické vlastnosti)