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This work deals with a dynamic mechanical analysis (DMA) study on the effect of a novel interfacial agent containing maleated grafts on an industrial waste origin atactic polypropylene. This contains 3% of bridge-, backbone-, and terminal-grafted succinic anhydride groups (aPP-SA/SA). By considering a polymer blend as a special case of composite where the dispersed phase is mobile, it is assumed that both the amounts of polyamide 6 (PA6) and the interfacial agent (aPP-SA/SA) cause changes in the glass transition temperature of the polypropylene phase in the blend. In this work, we have used DMA parameters to evidence the real interfacial modifications caused by the presence of aPP-SA/SA in the isotactic polypropylene (iPP)/PA6 system at the iPP glass transition temperature on the basis that this is an unfavorable scenario for the action of aPP-SA/SA. Since each component of the blend is interacting with each other, and to include the influence of the dispersed phase, it is possible to use a Box–Wilson experimental design model by resembling the so-called “agent based models” to obtain algorithms forecasting the dynamic mechanical parameters (storage, E’, and loss moduli, E”) at the glass transition of iPP, in all the composition range of whatever iPP/PA6/aPP-SA/SA-modified blend. POLYM. ENG. SCI., 2019. © 2019 Society of Plastics Engineers., The results discussed at present work were partially obtained under the auspices of the MAT 2000-1499 and MAT2013-47902-C2-1-R Research Projects

By following the successful editorial pathway of the recently published former Special Issue dedicated to Organic–Inorganic Hybrid Materials [...]

The present article adequately supports a twofold objective. On one hand, the study of the dynamic mechanical behavior of polypropylene/polyamide-6 blends modified by a novel compatibilizer was the objective. This was previously obtained by chemical modification of an atactic polypropylene polymerization waste. On the other hand, the accurate predictions of these properties in the experimental space scanned was the objective. As a novelty, this compatibilizer contains grafts rather than just maleated ones. Therefore, it consists precisely of an atactic polymer containing succinic anhydride (SA) bridges and both backbone and terminal grafted succinyl-fluorescein groups (SFSA) attached to the atactic backbone (aPP-SFSA). Therefore, it contains 6.2% of total grafting (2.5% as SA and 3.7% as SF), which is equivalent to 6.2&middot, &times, 10&minus, 4 g&middot, mol&minus, 1. This interfacial agent was uniquely designed and obtained by the authors themselves. Essentially, this article focuses on how the beneficial effect of both PA6 and aPP-SFSA varies the elastic (E&rsquo, ) and the viscous (E&rsquo, &rsquo, ) behavior of the iPP/aPP-SFSA/PA6 blend at the iPP glass transition. Thus, we accurately measured the Dynamic Mechanical Analysis (DMA) parameters (E&rsquo, E&rsquo, ) at this specific point considering it represents an extremely unfavorable scenario for the interfacial modifier due to mobility restrictions. Hence, this evidences the real interfacial modifications caused by aPP-SFSA to the iPP/PA6 system. Even more, and since each of the necessary components in the blend typically interacts with one another, we employed a Box&ndash, Wilson experimental design by its marked resemblance to the &ldquo, agent-based models&rdquo, In this manner, we obtained complex algorithms accurately forecasting the dynamic mechanical behavior of the blends for all the composition range of the iPP/aPP-SFSA/PA6 system at the glass transition of iPP.

This work deals with the changes of the glass transition temperature (Tg) of the polymer in polypropylene/mica composites due to the combined and synergistic effect of the reinforcement and the interfacial modifier. In our case, we studied the effect on Tg of platy mica and an interfacial modifier with p-phenylen-bis-maleamic acid (pPBMA) grafted groups onto atactic polypropylene (aPP-pPBMA). This one contains 5.0 &times, 10&minus, 4 g&middot, mol&minus, 1 (15% w/w) grafted pPBMA and was previously obtained by the author&rsquo, s labs by using industrial polymerization wastes (aPP). The objective of the article must be perceived as two-fold. On one hand, the determination of the changes in the glass transition temperature of the isotactic polypropylene phase (iPP) due to both the reinforcement and the agent as determined form the damp factor in DMA analysis. On the other hand, forecasting the variation of this parameter (Tg) as a function of both the interfacial agent and reinforcement content. For such purposes, and by assuming the complex character of the iPP/aPP-pPBMA/Mica system, wherein interaction between the components will define the final behaviour, a Box&ndash, Wilson experimental design considering the amount of mica particles and of interface agent as the independent variables, and the Tg as the dependent one, has been used. By taking in mind that the glass transition is a design threshold for the ultimate properties of parts based in this type of organic&ndash, inorganic hybrid materials, the final purpose of the work is the prediction and interpretation of the effect of both variables on this key parameter.

According to the IUPAC (International Union of Pure and Applied Chemistry), a hybrid material is that composed of an intimate mixture of inorganic components, organic components, or both types of components which usually interpenetrate on scales of less than 1 μm [...], This research received no external funding.

This work deals with the study of the evolution (with temperature) of the in-phase (E′) and the out-of-phase (E″) moduli of polypropylene/mica composites with improved interfacial interactions by the presence of an industrial waste based interfacial modifier named as p-phenylen-bis-maleamic (pPBMA) acid grafted atactic polypropylene (aPP-pPBMA). This additive contains 15% w/w grafted pPBMA (5.0·10−4 g mol−1) obtained from polymer industrial wastes in the Polymer Engineering Group (GIP) labs. The purpose of the work is twofold. One, dynamic mechanical analysis (DMA) has been used to evidence the improvement in properties due to the interfacial modifications by the addition of the novel interfacial modifier (aPP-pPBMA). And two, to obtain a mathematical model to predict the DMA moduli of the composite at α and β transition temperatures. So, a Box-Wilson experimental design considering the amount of mica particles and of interfacial agent as independent variables, and the modulus as the dependent ones at each transition was used. Thus, the final purpose of the work is obtaining forecasts for the DMA parameters as a function of the composite components and of the type of temperature dependent relaxation phenomena taking place. POLYM. ENG. SCI., 2017. © 2017 Society of Plastics Engineers

The present work checks on the efficiency of a grafted atactic polypropylene, with a high level of succinic anhydride-grafted groups, as an interfacial modifier in Polypropylene/Short Carbon Fiber composites (iPP/SCF) by mean of Dynamic Mechanic Analysis (DMA). Additionally, Differential Scanning Calorimetry to determine the crystalline content of the different materials comes in support of the DMA results. Hence, this work has been designed as an exploratory study for incoming works wherein recovered carbon fibers (rSCF) will be evaluated as reinforcement of thermoplastic composites. Consequently, we studied two different polypropylene-based composites with extreme amounts, 15 and 40% w/w, of a commercial sized SCF. Notwithstanding, just to notice that the main relaxation processes associated to the iPP matrix in the pristine composites appear sharply affected by the SCF amount, influencing also the crystalline content of the iPP matrix. The glass transition region of the iPP matrix shows significant variations well correlated with both the processing history of both the pristine iPP and the composites, and evidences the efficiency of the interfacial modifier (aPP-SA/SA) revealed as a good candidate for improving the performance in PP/rSCF composites. POLYM. ENG. SCI., 2017. © 2017 Society of Plastics Engineers

This work deals with a dynamic mechanical analysis study on the effect of a novel interfacial agent containing grafts rather than maleated ones, in all the compositional spectra of the iPP/PA6 system. The interfacial agent used is an atactic polymer (from polymer wastes) with succinic bridges and both backbone and terminal grafted succinil fluoresceine groups (aPP-SF/SA) containing 6.2 % of total grafted groups (2.5% SA and 3.7% SF), equivalent to 6.2 ·10-4¿g.mol¿1, obtained at the authors¿ labs. The effects of both PA6 and aPP-SFSA cause changes in the glass transition temperature (Tg) of iPP in the blend. One of the novelties of the work is introducing an interfacial agent with other groups rather than only maleic anhydride, capable to modify the behavior of the system in a positive, and very different manner, than raditional maleated agents. This has let a better understanding of the interphase between components. In this work we have used dynamic mechanical parameters to evidence the interfacial modifications caused by the presence of aPP-SF/SA in the iPP/PA6 system at the iPP Tg. Besides, by considering each component of the blend as interacting each other, we have used a Box-Wilson model by resembling the so called ¿agent based models¿ to obtain algorithms capable to make forecasts of the dynamic mechanical parameters (storage, E¿, and loss moduli, E¿¿, at the glass transition of iPP, in all the composition range of whatever iPP/PA6/aPP-SFSA modified blend.

The main aim of the present work is to correlate the morphological changes observed in the modified PP/PA6 fifty/fifty blends molded at confined flow conditions with both their mechanical and thermal properties and the kind and the amount of the interfacial modifiers used. Both transmitted light optical microscopy in the positive phase contrast mode, PC TOM, and field emission scanning electronic microscopy, FE SEM, were the used techniques for, respectively, general morphology overview and fractures surface analysis. The interfacial modifiers, a succinic anhydride, aPP-SA, and a succinyl-fluorescein, aPP-SF/SA, grafted atactic polypropylenes obtained and well characterized in authors’ laboratories came from the chemical modification of an atactic polypropylene industrial by-product. The amounts of any of both the interfacial modifiers came coded by the Box-Wilson experiment design methodology applied to the overall PP/PA6 binary system, watching that the interfacial agent was not a third component on a ternary blend but a true interfacial modifier in a binary one. All the studies were carried out over suitable specimens according to each test procedure with no further material manipulations to preserve at any moment the morphology of the blends as they emerge from the compression molding step at confined flow conditions.

The present article is twofold. One of the purposes of this work lies in the study of the impact behavior of the polypropylene/mica system incorporating an interface modifier obtained from an industrial polymerization byproduct. The interface agent used was a p-phenylen-bis-maleamic grafted atactic polypropylene (aPP-pPBMA) obtained in our labs. The other objective is to obtain a mathematical model capable of forecasting the composite properties accurately. Consequently, this work has been undertaken by using a statistical Box-Wilson experimental design in order to model the behavior of the composite system in terms of Charpy impact parameters. Two independent variables have been considered, the amount of mica particles and of interface agent. Impact strength, maximum force, and deformation were the dependent variables in the models. The existence of critical values in mica and interface agent optimizing the impact behavior is established. Additionally, an excellent correlation between the impact strength and the strength results coming from flexural and tensile tests is found. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44619., This work was partially supported by the MAT 2013-47902-C2-1- R; CTM 2013-48887-C2-2R and MAT 2000-1499; Spanish Research Projects financed by MINECO.

Present communication is devoted to the study of the effect of a novel interfacial agent in polypropylene/carbon fibre composites. The interfacial agent used is a succinic anhydride grafted atactic polypropylene containing both succinic bridges and side grafts (aPP-SASA) and with 5.6% (5.6.10−4g/mol) of grafting content obtained at the GIP labs. The study considers the study dynamic-mechanical behaviour with temperature at a frequency of 1 hz to ascertain the differences in the interfacial activity. The samples were compression molded in order to isolate as far as possible the effect of the solely aPP-SASA in absence of those synergetic effects due to the preferential orientation of the fibres.

This work deals with the study of the evolution with temperature of the in-phase and the out-of-phase responses of polypropylene/mica composites with improved interfacial interactions due to the presence of an industrial waste based interfacial modifier. This one is a p-phenylen-bis-maleamic acid grafted atactic polypropylene (aPP-pPBMA) with 15% w/w grafted pPBMA (5.0·10−4 g.mol−1). This work has been two-fold planned. On one hand, we have used dynamic mechanical parameters to evidence the interfacial improve caused by the addition of the interfacial modifier (aPP-pPBMA). The other purpose has been to obtain a mathematical to predict the overall behaviour of the heterogeneous system for whatever temperature considered. In our case we have merely used the dynamic-mechanical analysis (DMA) for just the α and β transition temperatures. Hence, a Box-Wilson experimental design considering the amount of mica particles and of interfacial agent as independent variables was used to obtain the mathematical model. The study has been tackled by considering the different transitions of the polypropylene matrix in the temperature interval scanned and further application of the Statistical Design of Experiments (sDOE) to each transition temperature in order to make forecasts for the property (E’, E”) as a function of the composite components and of the type of temperature dependent relaxation phenomena taking place.

Present work is devoted to the study of the tensile behavior of polypropylene (PP)/mica composites with improved interfacial interactions from the matrix side caused by the presence of a p-phenylen-bis-maleamic acid grafted atactic polypropylene (aPP-pPBM) as an interfacial agent. Hence, aPP-pPBM was previously obtained, in our laboratories, by reactive processing in the melt of a by-product (atactic PP) from industrial polymerization reactors. Present article is two-fold, on one hand it has been planned to evidence the so called interfacial effects caused by this novel interfacial agent (aPP-pPBM) yielding better final properties of the heterogeneous system as a whole as revealed by tensile mechanical properties, and on the other to obtain models to forecast the overall behavior of the system. For such purpose, a Box-Wilson experimental design considering the amount of mica particles and of interfacial agent as independent variables was used to obtain polynomials to forecast the behavior of the PP/Mica system in the experimental space scanned. The existence of a critical amount of aPP-pPBM to optimize mechanical properties appears to emerge. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

This article compares the batch solution and molten state chemical modification of an atactic polypropylene to yield a grafted polypropylene. Short reaction times appear to be sufficient and indeed necessary for the highest graft yields to be obtained if degradative processes occurring in both reaction media are to be avoided. The consecutive reactions for the optimized grafting reaction pathway were proposed for the solution process in an earlier article. The present work attempts to correlate this pathway with that of the molten state process. Grafted succinic anhydride groups react with two resorcine molecules to yield grafted succinyl-fluorescein groups. This work considers the resorcine units as true molecular probes, to be able to stabilize and activate the complexes formed between the succinic anhydride groups and the propylene sequence. This work shows the unsteady and later dynamic character of the process. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 345–351, 2007

Multiphase triblock styrene-b-(ethylene-co-butylene)-b-styrene (SEBS) copolymers chemically modified with maleic anhydride (MAH) in the presence of a radical initiator by reactive extrusion were studied by solid-state 1H-NMR and 13C-NMR. In the experiments performed, the concentrations of MAH and initiator were kept constant, whereas the temperature profile in the extruder was varied. Samples with known extents of grafting and crosslinking were analyzed with NMR with techniques based on proton spin diffusion to investigate the microphase structure of the modified copolymers. The 13C-NMR results show that the size of the rigid domains was about 15 nm and was not significantly changed by the modification. Alterations in the rubbery phase were illustrated by measured changes in proton spin-spin (T2) relaxation times. The fraction of protons having intermediate mobilities increased slightly in modified SEBS with respect to that observed in unmodified copolymers. These results were found to be independent of the extruder temperature profiles used, at least in the range studied. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

The interfacial changes associated with a series of polypropylene based composite materials with modified interphases from the reinforcement side, from the matrix side and both were studied by following their dynamic mechanical behavior. Composites consisted in an isotactic polypropylene (iPP) matrix, a series of talc with different surface functionalities (hydroxyl, chloride, n-butyl amine, and silanes) and a commercial interfacial agent form the matrix side (iPP-SA with 5% of grafts). A comprehensive interpretation of the link existing between the dynamic mechanical responses of the series of 75/25 iPP/talc composites and the molecular relaxation spectrum occurring in the polymer phase of the composites is made with emphasis on the role played by the interfacial modifications performed from each and both sides of the interphase. Dynamic mechanical analysis has been used here to study how the intended interfacial modifications affected the behavior of the composites. The efficiency of the interfacial phenomena is discussed from a phenomenological point of view as well as by considering classical criteria such as the glass transition temperature and the glass to rubbery transition. Finally, a correlation between mechanical parameters from the microscopic scale and others from the macroscopic scale appears to emerge.

The study of the flexural behavior of the polypropylene/mica system with modified interface by the presence of an interfacial agent obtained from an industrial polymerization by-product is one of the purposes of present work. The interfacial agent used was a p-phenylen-bis-maleamic grafted atactic polypropylene, aPP-pPBMA, obtained in authors' laboratories. Jointly to the study of the effect of the interfacial modification in the composite system, this paper has tried to underline a mathematical model to make predictions of the ultimate properties of the composite. So, a statistical two independent variables Box-Wilson experimental design have been used to model the behavior of the composite system. The two independent variables considered were the amount of mica particles and of interfacial agent. The fact that the flexural test consist in a combination of compressive and tensile stresses emerges from the analysis of both the data and the statistic parameters of the model. Additionally, a lower sensitivity to changes in the amount of the interfacial agent is found if compared to the obtained for tensile properties. Furthermore, an excellent correlation emerges between the flexural modulus forecasts and those obtained under tensile conditions.

This article reports the chemical modification of an atactic polypropylene performed in solution. To model the process, a Box-Wilson experimental design was used, taking in to consideration the concentrations of maleic anhydride and dycumile peroxide, as well as reaction time, as independent variables. The dynamic character of the process is proposed on the basis of model forecasts supported by experimental results. The proposed kinetic pathway agrees with the fact that short reaction times are not only sufficient but necessary for the greatest graft yields to be attained, while preventing degradative processes in the system. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1182–1190, 2006.

Synchrotron infrared (IR) microscopy is used to study multiphase polymer systems. Data is obtained at high spatial resolution from polymer blends, composites, and polymorphic isotactic polypropylene, and spectra are recorded successfully with apertures as small as 3 µm × 3 µm due to the high brightness of the synchrotron IR source.

This study was concerned with the chemical modification process of an atactic polypropylene from polymerization reactor byproducts with p-phenylen-bismaleamic acid to obtain a new grafted polymer supposed to play an important role as an interfacial agent in heterogeneous systems based on polymers. The grafting process was undertaken with the aid of the Box–Wilson experimental worksheet, with two independent variables (or controlled factors), the level of polar monomer to be grafted in the polymer and the concentration of the initiator, and with the agitation rate kept constant. Each item of the experimental design was performed at four different reaction times. This latter let us ascertain the transient nature of the process and the existence of a critical point in the concentration of both reactants conducting the system to the maximum grafting yield. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2202–2209, 2003

The subject of this work is the thermal behaviour of polypropylene/talc composites whose interface has been modified by atactic polypropylenes containing different numbers of succinyl fluorescein grafted groups. The interface modifiers used here were previously obtained in our laboratories by a two-step chemical modification of the melt of a by-product (atactic polypropylene) of industrial polymerisation reactors. The variations in interface activity caused by replacing a small amount of the polypropylene matrix in the composite by succinyl fluorescein grafted atactic polypropylene were clearly detected by differential scanning calorimetry as thermal responses. These studies show that interface agents are preferably located in the amorphous phase of the system. A correlation between the crystalline content of the polymer component and the degree of grafting of the interface agent is also established. Further, a relationship between the thermal behaviour and the mechanical properties of the system seems to emerge.

Present work is devoted to the changes produced in the interfacial interactions caused by an interfacial agent consisting in succinil-fluoresceine grafted atactic polypropylene acting into a polypropylene/talc composite as revealed by dynamic–mechanical spectrometry. The interfacial agents used here were previously obtained in our laboratories by means of a two step process of chemical modification in the melt of a by-product (atactic polypropylene) from industrial polymerization reactors, and consist in four different additives with 1–4% w/w of grafting degree expressed as succinic equivalent. In this way, the variations of interfacial activity caused by replacing a little amount of polypropylene matrix in the composite by the succinil-fluoresceine grafted atactic polypropylene can be clearly detected. Furthermore, a correlation between parameters from the microscopical scale such as the obtained by DMA and other from the macroscopic such as mechanical properties appears to emerge.

This article reports on the interfacial modifications induced by different amounts of a succinyl-fluorescein grafted atactic polypropylene (a-PP-SF) as a truly interfacial agent in polypropylene/talc composite materials. The a-PP-SF used, which contains 4% grafts, was previously obtained in our laboratory by chemical modification of a byproduct from industrial polymerization reactors. Thermal and mechanical analyses of composites, performed under dynamic conditions, led to the correlation of parameters at the microscopic scale with others at the macroscopic scale. Thus, the interfacial effect caused by different amounts of a-PP-SF in the composite can be concluded by observations made at either scale. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 1371–1382, 2002

This study investigates the role played by two different interface agents on the basis of atactic polypropylene in the continuous/disperse phase polypropylene/ polyamide-6 (PP/PA6) system. The two agents used were obtained at the authors' laboratories from an atactic polypropylene byproduct derived from industrial polymerization reactors and consist of two grafted polymers containing either succinic anhydride (a-PP-SA) or both succinyl-fluorescein and succinic anhydride grafted groups (a-PP-SF/SA). The role of these grafted polymers as compatibilizers in PP/PA6 polymer blends has been confirmed in previous investigations on the basis of their macroscopic behavior. This work investigates the thermal study of these blends where polypropylene acts as the polymer matrix and polyamide as the dispersed phase. Under isothermal conditions, thermal analysis agrees with the changes in the overall system behavior caused by the presence of the interface agents. These aspects were confirmed by polarized light microscopy that showed the morphology of the blends before and after modification with a-PP-SA or a-PP-SF/SA.

Present work concerns to the study of the dynamic mechanical and thermal responses of selected polypropylene (iPP)/ mica composites with a modified interface from the matrix side by using a p-phenylen-bis-maleamic acid grafted atactic polypropyl- ene, coming from a byproduct of industrial polymerization reactors. Thus, the study is mainly focused on the 75/25 iPP/mica ratio since it was identified in previous works as providing the maximum inter mica particle distance to assure they should participate in the overall process of dissipation of the mechanical energy supplied to the composites. Hence, the present dynamic mechanical analy- sis discussion tries to correlate the damping responses of the injection-molded composites with those previously obtained but over compression molded composites as the basis of further studies all along the compositional iPP/mica map. Therefore, the latter let us, on the one hand, to follow how the main values of the different dynamic mechanical analysis parameters vary because of the interfa- cial modifier presence, and on the other, to develop a robust correlation between them and the corresponding macroscopic mechani- cal parameters, This work was supported in part by the MAT2000–1499 and the CTM2013–48887-C2–2-R Spanish Projects.

The thermal behavior in dynamic conditions of polypropylene/polyamide 6 (PP/PA6) blends with a modified interphase is discussed in terms of the crystallinities of the polypropylene and polyamide components imposed by the processing step conditions and after removal of those constraints by holding the blends 5 min in the molten state in the calorimeter. As interfacial agents, two based on succinic anhydride or succinil-fluoresceine grafted atactic polypropylenes were used. The experimental program was run following the Box-Wilson experimental design methodology. Thermal scans were made using round samples (5 mm diameter and 100 μm thick) cut from compression-molded sheets with morphologies and macroscopic behavior studied previously. Changes of the amount of crystallinity of each polymer in the modified blends are contrasted with the tensile strength values of the heterogeneous materials as a whole; evidence of the different roles played by each interfacial agent acting at the interface among blend compone...

In this study the thermal and mechanical behaviors of PP/mica composites, under dynamic conditions, are discussed on the basis of the changes induced by the presence of the interfacial modifier succinic anhydride–grafted atactic polypropylene, with different degrees of grafting, prepared in our laboratories by chemical modification of a by-product from industrial polymerization reactor. Changes in the interfacial activity, induced by the substitution of a very small amount of polymer matrix by the interfacial agent with different grafting levels, were conclusively obtained. The results obtained from either the thermal or the dynamic mechanical behavior led to the same conclusions, and agree with data obtained from macroscopic mechanical properties. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 625–636, 2001

Following earlier studies on chemical modification processes of polypropylenes by polar monomers, a new study by grafting p-phenylen-bis-maleamic acid in the molten state has been carried out. In a previous work a four independent variable Box–Wilson experimental design lets us conclude the adequacy of working at a certain gear rate and low times of reaction. This is the reason why, in this work, a two independent variable design (reactant concentrations) has been used and applied to four different times of reaction in order to check those findings. Besides, it is also confirmed that the process follows an oscillating evolution of grafting level with the reaction time, and the existence of critical points for the reactant concentrations (p-phenylen-bis-maleamic acid and dycumile peroxide). These facts seem to agree with a chemisorption mechanism, governing the reaction yields in this kind of reactive systems, where the main and limiting role is played by the macromolecular substrate.

Variations related to the thermal behavior and morphology of isotactic polypropylenes (i-PP) with p-phenylen-bis-maleamic acid groups are studied in this work. Changes in peak temperatures and crystalline levels are discussed on the basis of not only the grafting degree of each sample but also of the experimental conditions used to obtain them. A secondary crystallization phenomenon is found to emerge from the second fusion scan, and confirmed by morphological studies. An explanation of this phenomenon is established on the basis of the grafted groups bonded in the polypropylene macromolecular backbone.

The dynamic thermal and mechanical behavior of Polypropylene/Mica composites-with improved properties induced by the presence of succinil-fluoresceine groups onto atactic polypropylene with different grafting levels-is the subject of this article. A further correlation of these with the macroscopic mechanical performance of the composite materials is also discovered. The atactic polypropylenes containing succinil-fluoresceine grafted groups were previously obtained in our laboratories by chemical modification of a byproduct of industrial polymerization reactors. The interfacial modifications induced by replacing a little amount of polymer matrix in the composite material by the grafted atactic polypropylene is clearly concluded either from a microscopic or a macroscopic point of view.

Variations related to the thermal behaviour of succinic anhydride modified polyolefins are discussed in this work. Changes in fusion/crystallization steps recorded under dynamical conditions using differencial scanning calorimetry are studied. The main goal of this work is to demonstrate the influence of reaction conditions on the behaviour of modified polymers, as well as the role played by the substituent grafted in the polyolefins under study. Differences in fusion and crystallization temperatures and in crystallinity assumed to be due to the grafted groups (and then to the reaction conditions) are discussed.

The FTIR quantitative evaluation of grafting succinic anhydride onto polypropylenes is presented. It was done by correlating relative absorbance values obtained from IR spectra with grafting levels of the sample as determined by an improved traditional hot titration method. The results obtained seem to be valid for either atactic or isotactic modified polypropylenes and suggest a careful review about how this technique is usually used in the quantification of polar groups grafted onto polyolefins. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 2837–2847, 1999

Chemical modification of an industrial waste (atactic polypropylene) using a two-step process to obtain a fluorescent-modified polyolefin is the subject of this article. For these purposes, a Box–Wilson statistical experimental design has been used. The product was obtained by a condensation reaction after a previous one via a radical reaction had taken place in the melt. Furthermore, the nature of this product reveals that only single succinic anhydride groups were previously grafted onto polymers coming from the previous radicular reaction. © 1998 John Wiley & Sons, Inc. J. Appl. Polym. Sci. 70: 689–696, 1998

The determination of the influence of the reaction conditions on chemical modification yielding of polypropylene by a polar monomer (p-phenylen-bis maleamic acid) in melt by using a Box-Wilson experimental design is the main goal of this article. The following 4 independent variables were considered to be mainly affecting the process, initial concentration of reactants ( polar monomer and peroxide ), gear rate, and reaction time in a batch reactor.