Academic literature on the topic 'Natural compatibilizer'

The effects of graft copolymers applied as compatibilizers for natural rubber/nitrile rubber (NR/NBR) blends at 50/50 (w/w) on cure characteristics, mechanical properties, thermal properties, oil resistance, and morphology were investigated. The graft copolymers of methyl methacrylate (MMA) onto NR initiated by benzoyl peroxide (NR- g-PMMA<BPO>) and by potassium persulfate (NR- g-PMMA<PPS>) under emulsion polymerization were synthesized and used to compatibilize the blends. The structures of the copolymers were characterized by Fourier transform infrared spectroscopy and proton nuclear magnetic resonance spectroscopy. NR was blended with NBR via a two-roll mill at 70°C under the compatibilizer loading ranging from 0 to 10 parts per hundred of rubber (phr). The results showed that the tensile property and tear strength of the blends increased with the increasing amount of NR- g-PMMA<BPO> as a compatibilizer. Thermal aging determined in terms of tensile properties exhibited the smaller difference between before and after aging in an oven with the increasing compatibilizer loading. The morphology of the compatibilized NR/NBR vulcanizates was investigated by scanning electron microscopy of the tensile fracture surfaces, which exhibited the improvement of interfacial adhesion between the two rubber phases. The thermal properties of compatibilized NR/NBR vulcanizates were reported in terms of a glass transition temperature under differential scanning calorimetry and dynamic mechanical analysis. The incorporation of an appropriate amount of the compatibilizer into the blends apparently improved the oil resistance of NR. Among them, the blend filled with 7.5 phr of NR- g-PMMA<BPO> showed the lowest volume change in IRM 903 oil.

ABSTRACT An exploration of the effect of epoxidized NR with 50 mole% epoxide groups (ENR-50) as compatibilizer on the rubber–filler interaction of microcrystalline cellulose (MCC)-filled NR composites was conducted. The compatibilizing efficiency of ENR-50 was systematically examined in terms of cure and mechanical and thermal properties of NR/MCC composites. ENR-50 compatibilized NR/MCC composites showed moderate enhancement in the maximum rheometric torque and tensile properties compared to either uncompatibilized NR/MCC composite or unfilled NR system. The solvent uptake measurements indicated improved interfacial interaction between NR matrix and MCC in presence of ENR-50 as compatibilizer. A thermogravimetric analysis confirmed excellent improvement in the thermal stability of NR/MCC composite in the presence of ENR-50 as compatibilizer. Fourier transform infrared spectroscopy was used to explain the probable mechanism of interaction between NR matrix and MCC in the presence of ENR-50.

The performance of rubber composite relies on the compatibility between rubber and filler. This is specifically of concern when preparing composites with very different polarities of the rubber matrix and the filler. However, a suitable compatibilizer can mediate the interactions. In this study, composites of natural rubber (NR) with halloysite nanotubes (HNT) were prepared with maleated natural rubber (MNR) and modified palm stearin (MPS) as dual compatibilizers. The MPS dose ranged within 0.5–1.5 phr, while the MNR dose was fixed at 10 phr in all formulations. It was found that the mixed MNR/MPS significantly enhanced modulus, tensile strength, and tear strength of the composites. The improvements were mainly due to improved rubber-HNT interactions arising from hydrogen bonds formed in the presence of these two compatibilizers. This was clearly verified by observing the Payne effect. Apart from that, the MPS also acted as a plasticizer to provide improved dispersion of HNT. It was clearly demonstrated that MNR and MPS as dual compatibilizers improved rubber-HNT interactions and reduced filler-filler interactions, which then improved tensile and tear strengths, as well as dynamical properties. Therefore, the mix of MNR and MPS had a great potential to compatibilize non-polar rubber with HNT filler.

Abstract A biodegradable thermoplastic elastomer (TPE) blend is developed by blending poly (lactic acid) (PLA) and natural rubber (NR) or epoxidized natural rubber (ENR) and it is a sustainable substitution in recent years for synthetic polymers. PLA is high in mechanical strength and compostable, but it is highly stiff and brittle. The incorporation of NR or ENR to PLA increases the impact strength and toughness of PLA. However, the disparity in polarity between PLA and elastomer phase like NR and ENR results in TPE blend being incompatible. Hence, compatibilization is essential to improve its polarity and develop interactions. Compatibilizer that composed of two different polymer is known is graft compatibilizer with the aid of grafting agent. The graft compatibilizers are divided into two categories. The first type is made up of one polymer and grafting agent and, the other one is composed of two polymer groups and grafting agent. These two types of graft compatibilizer can be prepared via two different method such as direct melt blending and solution. Apart from this, the TPE blend is produced via the melt blending technique with mixing machines such as internal mixer and extruder. This article has reviewed the preparation of the graft compatibilizer and blending technique of TPE. Based on the findings, the graft compatibilizers has a significant role in improving miscibility and compatibility across blend composed of different phase.

Natural fiber reinforced composites are increasingly being used in various applications area. Therefore, the processing method and physical properties of these composites are very important parameters in product quality and quaranty. This paper focused on the tensile properties, Fourier transform infrared (FTIR) and water absorption of cogon grass (CG) with low density polyethylene (LDPE)/soya spent flour (SSF) composites. The tensile strength and elongation at break (Eb) of uncompatibilized CG with LDPE/ SSF decreased significantly with increasing of fiber content. However, the Young’s modulus increased with increasing of CG loading. The presence of epoxidized natural rubber (ENR 50) as a compatibilizer increased the tensile strength, Eband Young’s modulus of the composites when compared to uncompatibilized composites. Fourier transform infrared results show distinguishable peaks for compatibilized and uncompatibilized composites. The water absorption for both uncompatibilized and compatibilized composites increased from day 1 until day 21. The presence of ENR 50 as compatibilizer showed lower water absorption percentage compared to uncompatibilized composites.

The effects of epoxidized natural rubber as a compatibilizer in modified-montmorillonite filled natural rubber were studied. Natural rubber was compounded with 2, 5 and 10 parts per hundred rubber (phr) of organomodified montmorillonite as a reinforcing filler and cured by using a conventional sulfuric system. Epoxidized natural rubber with 25 and 50 mol% epoxidic units (ENR25 and ENR50, respectively) was used as compatibilizer at the amount of 5, 10 and 15 phr. Rubber compounds were then tested for their curing properties. Test specimens for mechanical testing were prepared by compression molding. The use of montmorillonite as a filler in natural rubber efficiently improved mechanical properties that are tensile strength, modulus, elongation at break, tear strength and hardness, especially with the small amount of montmorillonite. This is supposed to be related to intercalation and exfoliation process. The increasing amount of montmorillonite caused the filler to be agglomerated thus the reinforcing efficiency was reduced and some mechanical properties were dropped. It was further founded that epoxidized natural rubber compatibilized montmorillonite filled natural rubber effectively. As the amount of epoxidized natural rubber increased, the mechanical properties tended to increase. The presence of epoxidized natural rubber improved filler-rubber interaction and filler dispersion. The compatibilizing efficiency of ENR25 was slightly superior to that of ENR50. This is because ENR 25 contains more double bonds than ENR 50 hence higher strain-induced crystallinity is occurred

Abstract Natural rubber (NR)/montmorillonite (MMT) nanocomposites compatibilized with epoxidized natural rubber (ENR) were produced by latex compounding method. The effects of ENR as a compatibilizer on NR/MMT nanocomposites were investigated. The addition of ENR brought intercalation or exfoliation of the clay, which improved the clay dispersion in the rubber matrix, as characterized by X-ray diffraction (XRD) and transmission electronic microscopy (TEM). The interfacial interaction of ENR with MMT was investigated by Fourier transform infrared spectroscopy (FTIR). The vulcanization was hindered by the incorporation of ENR, while the mechanical performances, thermal stability and ageing resistance were improved. The glass transition temperature and storage modulus increased with ENR loading, which was corroborated by dynamic mechanical analysis (DMA).

This research aims to investigate the efficiency of polybutadiene-grafted maleic anhydride (PB-g-MAH) as the compatibilizer for ethylene-propylene diene rubber and epoxidized natural rubber (EPDM/ENR) blends. PB-g-MAH was varied from 0-10 parts per hundred parts of rubber (phr), and the cure characteristics, mechanical and dynamic properties of 70/30 EPDM/ENR blends with and without compatibilizer were evaluated. It was found that the minimum torque, maximum torque, scorch and cure times of the blends increased after adding PB-g-MAH, whereas cure rate decreased. The morphology of the blend is improved by the addition of PB-g-MAH in small amounts, owing to an improved compatibility of these rubbers confirmed by dynamic mechanical property. The hardness and oil resistance increased with increasing PB-g-MAH content. Of all blends investigated, the blend compatibilized with 2-4 phr of PB-g-MAH shows the optimum mechanical properties and thermal resistance.

Polymer composite sheets using a low-cost filler (local natural sand) and polymer (high-density polyethylene, HDPE) as a replacement of the traditionally used wood-fiber-based sheets for paper-based applications were developed. The sand/polymer composite sheets were prepared by melt extrusion in a melt blender followed by compression molding. The effects of varying particle size, concentration, and the use of a compatibilizer (polyethylene-grafted maleic anhydride) was studied on the mechano-chemical performance properties of the composite sheets such as morphology, thermal and mechanical properties, and wettability characteristics used in the printing industry. In terms of thermal stability, filler (sand) or compatibilizer addition did not alter the crystallization, melting, or degradation temperatures significantly, thereby promoting good thermal stability of the prepared sheets. Compatibilization improved anti-wetting property with water. Additionally, for the compatibilized sheets prepared from 25 µm sand particles, at 35 wt%, the contact angle with printing ink decreased from 44° to 38.30°, suggesting improved ink-wetting performance. A decrease in the elastic modulus was also observed with the addition of the compatibilizer, with comparable results to commercial stone paper. Results from this study will be considered as a first step towards understanding compatibility of local natural sand and polymers for paper-based application.

Coconut shell (CS) is one of agro-waste material which has high natural lignocellulosics content. This material provides a potential resource as a reinforcement agent in thermoplastic elastomeric olefin (TEO). In this study, CS was used as filler in TEO composites. The effect of CS loading and Maleic Anhydride Polypropylene (MAPP) as compatibilizer on mechanical properties, morphology and thermal properties were studied. Results show that the increasing of CS loading has increased the tensile strength, elongation at break and Young's modulus of TEO/CS composites. At similar content, the effect of PP-g-MA as compatibilizer has improved the tensile strength, elongation at break and Young's modulus of TEO/CS composites. The SEM study of the tensile fracture surface of compatibilized composites indicates that the presence of PP-g-MA increased the interfacial interaction. TGA results show that the composites with addition of MAPP as a compatibilizer has better the thermal stability compared to composites without addition of MAPP at 600 °C. DSC analysis showed that the addition of MAPP decreases the crystallinity of TEO/CS composites. It was found that the presence of MAPP will extended the molecular chain of the TEO/CS composites. Keywords: thermoplastic olefin, coconut shell, compatibilizer, composites

Des copolymères greffés à base de caoutchouc naturel (NR) et de poly(acryloyloxyméthylphosphonate de diméthyle) (NR-g-PDMAMP), de poly(méthacryloyloxyéthylphosphonate de diméthyle) (NR-g-PDMMEP) et de poly(méthacryloyloxyméthylphosphonate de diméthyle) (NR-gPDMMMP), ont été synthétisés en milieu latex selon la méthode dite « grafting from » à partir de sites amorceurs photosensibles N ,Ndiéthyldithiocarbamate préalablement introduits le long des chaînes 1,4-polyisoprène du caoutchouc naturel. Des études de compatibilisation des mélanges caoutchouc naturel (NR) / copolymère d'éthylène - acétate de vinyle (EV A) ont par la suite été envisagées avec le copolymère NR-gPDMMMP, choisi comme agent compatibilisant. Elles ont été effectuées sur des mélanges simples 50/50 NR/EV A, mais aussi des mélanges dynamiquement vulcanisés 40/60 NR/EVA. Dans les deux cas,les influences du taux de greffage du NR-g-PDMMMP (71, 80, 89, et 95%) et du taux de chargement en compatibilisant (0, 1,3,5,7,9,12, et 15 % en poids par rapport au NR) sur les propriétés rhéologiques, dynamiques, mécaniques, morphologiques, et thermiques, ont été étudiées. Les meilleurs effets de compatibilisation ont été observées avec un copolymère NR-g-PDMMMP ayant un taux de greffage de 80 %, pour un taux de chargement de 7 % dans le cas du mélange simple 50/50 NR/EV A et de 9 % dans celui du mélange dynamiquement vulcanisé 40/60 NR/EV A. Les études microscopiques par SEM des mélanges ont montré une réduction de la taille des domaines. Il a aussi été noté que la stabilité thermique du mélange NR/EVA se trouve renforcée avec l'incorporation du NR-g-PDMMMP
Graft copolymers of natural rubber and poly(dimethyl(acryloyloxymethyl)phosphonate) (NR-g-PDMAMP), natural rubber and poly(dimethyl(methacryloyloxyethyl)phosphonate) (NR-g-PDMMEP), and natural rubber and poly(dimethyl(methacryloyloxymethyl)phosphonate) (NR-g-PDMMMP), were prepared in latex medium via a "grafting from" methodology based on the photopolymerization of vinyl monomers initiated from N,N-diethyldithiocarbamate groups previously bound in side position of the 1,4-polyisoprene chains of natural rubber. Thereafter, compatibilization studies of natural rubber (NR) / ethylene vinyl acetate copolymer (EV A) blends were considered using NR-g-PDMMMP as a blend compatibilizer. The investigations were carried out on two categories of blends : uncured 50/50 and dynamically cured 40/60 NR/EV A blends. Ln the two cases, the influences of NR-g-PDMMMP grafting rates (i. E. , 71, 80, 89, and 95 %) and of loading level in compatibilizer (i. E. , 0, 1,3,5,7,9,12, and 15 wt% compared to NR) on rheological, dynamical, mechanical, morphological, and thermal properties, were studied. The best compatibilization effects were observed with a NR-g-PDMMMP having a grafting rate equal to 80 %, at a loading level of 7 wt% for 50/50 uncured blend and 9 wt% for 40/60 dynamically cured blend. In these conditions, the highest complex viscosity (positive deviation), tensile strength, and elongation at break, as well as the lowest values of tension set and tan d (damping factor), were observed. SEM micrographs of compatibilized blends showed a size decrease of the domains. It was also noted that the thermal stability of NR/EV A blends was improved by incorporating NR-g-PDMMMP

The influences of reactive extrusion of poly(lactic acid) (PLA)-based bio(nano)composites on their properties are described. Reactive compatibilizers were used to enable good dispersion of natural (nano)fibers in the thermoplastic matrix consisting of PLA/poly(butylene adipate-co-terephthalate) (PBAT) and PLA/polycarbonate (PC) blends. At the same time, chain extenders were used for the modification of immiscible thermoplastics, PLA and PBAT, in order to achieve good miscibility of the PLA/PBAT blend. In the experimental part, the main obstacle of PLA, its brittleness, was improved in three different series of bio(nano)composites. Reactive extrusion with PLA/PBAT blends and the addition of hops as a chain extender and compatibilizer increased the elongation at break of the bio(nano)composite by more than 240% and the impact strength by 200% compared to neat PLA. Reactive extrusion of PLA/PBAT blends and addition of 1% nanocrystalline cellulose (NCC) with additives increased the elongation at break by more than 730% compared to pure PLA, and the sample did not break during the impact testing. Reactive extrusion with PLA/PC blends and the addition of 1 wt% NCC with additives increased the elongation at break by more than 90% and the impact strength by more than 160% compared to pure PLA.

Segons la legislació vigent a Catalunya, cal fer un procés d’avaluació ambiental de plans i programes públics, com a eina de prevenció, que permeti integrar els aspectes ambientals en la presa de decisions. Els plans d’ordenació urbanística municipal queden inclosos com a plans públics i han de tenir en compte l’execució d’aquesta avaluació ambiental i, concretament, les actuacions i la documentació que exigeix la normativa vigent (article 7 de la Llei 9/2006, de 28 d’abril, sobre l’avaluació dels efectes de determinats plans i programes sobre el medi ambient). El Pla d’ordenació urbanística municipal (en endavant, POUM) de Besalú, 2007, ha tingut, com a instrument d’avaluació ambiental, l’Informe de sostenibilitat ambiental (en endavant, ISA), el qual té per objectiu oferir un seguit de criteris sostenibles que serveixin de base per al desenvolupament urbanístic del municipi, basant-se en la integració dels principis de sostenibilitat establerts pel Decret 305/2006, la Llei estatal 9/2006, la Directiva 2001/42/CE i la nova Llei d’avaluació ambiental de plans i programes (AAPP) de Catalunya, aprovada pel Parlament de Catalunya el 15 d’abril de 2009. La Llei d’urbanisme i el seu Reglament es pronuncien clarament a favor d’un desenvolupament urbanístic sostenible, sobre la base de la utilització racional del territori, per compatibilitzar el creixement i el dinamisme econòmic necessaris amb la cohesió social, el respecte al medi ambient i la qualitat de vida de les generacions actuals i futures. Segons la Directiva 2001/42/CE, els elements ambientals de sostenibilitat que ha d’incorporar un Pla d’ordenació urbanística municipal s’han d’integrar des del primer moment en la presa de decisions que comporta la formulació del planejament. Per aquest motiu, és necessari fixar uns objectius ambientals, que són els següents: * Diagnòstic ambiental del territori. * Fixació d’objectius ambientals. * Determinació d’indicadors del compliment dels objectius marcats. * Incorporació dels objectius ambientals en les determinacions del planejament: d’ordenació, de normatives, de programació i de finançament. * Validació del compliment dels objectius establerts. * Mesures de desplegament i de seguiment. Segons l’art. 3.1 del Decret legislatiu 1/2005, de 26 de juliol, d’urbanisme, s’entén per principi de sostenibilitat relacionat amb el planejament urbanístic: “El desenvolupament urbanístic sostenible es defineix com la utilització racional del territori i el medi ambient i comporta conjuminar les necessitats de creixement amb la preservació dels recursos naturals i dels valors paisatgístics, arqueològics, històrics i culturals, a fi de garantir la qualitat de vida de les generacions presents i futures”. Aquest estudi de cas vol destacar la importància que va tenir l’anàlisi ambiental i l’avaluació de les característiques socioambientals més significatives dels nous sectors de creixement proposats i de les àrees objecte de modificació i/o transformació, així com les del seu context territorial immediat (mesura requerida al document de referència, emès per l’òrgan ambiental competent: “Oficina territorial d’avaluació ambiental estratègica de Girona”), per tal de justificar l’ordenació urbanística d’acord amb uns criteris urbanístics i socioambientals sostenibles. Strategic environmental evaluation: Case study, Urban Plan, POUM Besalú (Catalonia). According to the existing legislation in Catalonia it is necessary as a preventative method to carry out a process of environmental evaluation for planning and for public programmes which would allow for the integration of environment issues in the decision making processes. The urban town plans are considered to be public plans and therefore they must take into account this environmental evaluation. In particular they must consider the necessary actions as well as the specific documentation which the existing regulation requires (article 7 of the 9/2006 Regulation of 28 April relating to the effects of certain plans and programmes on the environment). As an instrument for environmental evaluation, the Urban Town Plan (POUM) Besalú 2007, has done a report on environmental sustainability, (ISA). The objective of this report is to offer a series of sustainable criterion which serve as a basis for the town planning development, basing itself upon the integration of the sustainable principals established in: The 305/2006 Decree, the State Legislation 9/2006, the Directive 2001/42/CE and the blueprint of the Catalan Environmental Evaluation Legislation for Plans and Programmes (AAPP). The urbanistic Legislation and its Regulations indicate to be clearly in favour of a sustainable urban development based upon the rational use of land in order to create compatibility between growth and the necessary economic dynamism together with social cohesion, respect towards the environment and the quality of life of the present and future generations. According to the Directive 2001/42/CE, the sustainable environmental elements which ought to be incorporated into the Urban Town Plan need to be integrated from the beginning of the decision making process which is required in the establishing of the general layout plan. For this reason it is necessary to establish the following environmental objectives: * Environmental diagnosis of the site. * Establishment of environmental objectives. * Setting up of pointers for compliance of the established objectives. * Incorporation of environmental objectives in the setting up of town plans, regulations, programming and financing. * Verification of compliance with established objectives. * Deployment measures and follow up. According to the Town Planning article 3.1 of the Legislative Decree 1/2005 dated 26 July, the concept of sustainability related to urban layout is understood as the following: ”Sustainable urban development is defined as the rational use of land and the environment and it involves the combination of the needs of expansion with the preservation of natural resources while taking into consideration landscape, arqueological, historic and cultural values with the intention of guaranteeing the quality of life of present and future generations.” This case study wishes to highlight the importance of the environmental analysis and the evaluation of the most important social-environmental characteristics in the new sectors of proposed growth and in the areas subject to modification and/or transformation the same as those in the immediate territorial context(this measure is required in the reference Document emited by the appropriate environmental body “Girona Land strategic environmental evaluation Office”) in order to justify the urban plan in accordance with urbanistic and sustainable social-environmental criterion.