Estimating reactivity ratios in multicomponent polymerizations is becoming increasingly important. At the same time, using cumulative models is becoming imperative, as some multicomponent systems are inherently so fast that instantaneous "approximate" models can not be used. In the first part of the thesis, triad fractions (sequence length characteristics) are employed in a multiresponse scenario, investigating different error structures and levels. A comparison is given between instantaneous triad fraction models and instantaneous composition model, which represent the current state-of-the-art. In the second part of the thesis, extensions are discussed with cumulative composition and triad fraction models over the whole conversion range, thus relating the problem of reactivity ratio estimation to the optimal design of experiments (i. e. optimal sampling) over polymerization time and conversion. The performance of cumulative multiresponse models is superior to that of their instantaneous counterparts, which can be explained from an information content point of view. As a side-project, the existence of azeotropic points is investigated in terpolymer (Alfrey-Goldfinger equation) and tetrapolymer (Walling-Briggs equation) systems.

Estimating reactivity ratios in multicomponent polymerizations is becoming increasingly important. At the same time, using cumulative models is becoming imperative, as some multicomponent systems are inherently so fast that instantaneous "approximate" models can not be used. In the first part of the thesis, triad fractions (sequence length characteristics) are employed in a multiresponse scenario, investigating different error structures and levels. A comparison is given between instantaneous triad fraction models and instantaneous composition model, which represent the current state-of-the-art. In the second part of the thesis, extensions are discussed with cumulative composition and triad fraction models over the whole conversion range, thus relating the problem of reactivity ratio estimation to the optimal design of experiments (i. e. optimal sampling) over polymerization time and conversion. The performance of cumulative multiresponse models is superior to that of their instantaneous counterparts, which can be explained from an information content point of view. As a side-project, the existence of azeotropic points is investigated in terpolymer (Alfrey-Goldfinger equation) and tetrapolymer (Walling-Briggs equation) systems.

This thesis deals with the post-polymerization functionalization of a pH-responsive poly(styrene)-b-poly(4-vinyl pyridine)-b-poly(ethylene oxide) triblock terpolymer with stimuli responsive and diol-binding 2-bromomethyl-4-fluorophenylboronic acid and 2- bromomethyl-phenylboronic acid suitable for biomedical applications. A reproducible method of quaternization of poly(4-vinyl pyridine) block with prescriptible quaternization ratio was developed and the reaction yield was analyzed by 11 B, 1 H NMR and infrared spectroscopy. A reproducible self-assembly protocol for stable nanoparticles from functionalized stimuli-responsive triblock terpolymer was found, and the nanoparticles were studied by static, dynamic and electrophoretic light scattering, and cryogenic transmission electron microscopy. Fluorescence and UV-VIS spectroscopy measurements were performed for description of boron-ester linkages formation and hydrolysis with model drug Alizarin as a study of encapsulation and release reactions together with sugar sensing reactions for potential drug delivery.

Les effets électrocaloriques, qui se traduisent par une variation de température induite par une variation d’entropie ont été étudiés comme alternative aux systèmes de réfrigération utilisant un cycle de compression/détente. Le travail de thèse se focalise sur l’étude de l’effet élastocalorique dans le caoutchouc naturel et le terpolymère (P(VDF-TrFE-CTFE). En premier lieu, l’effet élastocalorique dans le caoutchouc naturel qui compte parmi les meilleurs candidats, a été évalué pour des cycles de déformation réalisés avec différentes valeurs d’allongement. Une variation de température de 4 °C a pu être observée. Il est usuel d’utiliser la relation déformation/contrainte en fonction de la variation de température pour évaluer l’effet élastocalorique. Il a été démontré que cette méthode ne peut pas être utilisée dans le cas du caoutchouc naturel et qu’elle doit être remplacée par la mesure de la variation de l’énergie mécanique en fonction de la température. Et dans ce cas, une variation linéaire entre ces deux dernières grandeurs a été observée. En réalisant un bilan d’énergie pendant l’essai, non seulement, le rendement énergétique a pu être évalué mais il a été aussi possible de prendre en compte l’effet Mullins et la cristallisation induite par la déformation pour le caoutchouc naturel. Dans un second temps, l’effet élastocalorique a été étudié sur le terpolymère (P(VDF-TrFE-CTFE), ce qui a permis de montrer qu’il était possible d’obtenir une variation de température de 2.1 °C sous réserver de pré-déformer le terpolymère à plus de 1050 % avant. Par comparaison avec d’autres matériaux présentant une bonne conversion élastocalorique, le fort potentiel de ce matériau a pu être mis en évidence. Enfin, il a été mis en évidence que la plus grande partie de l’énergie mécanique était bien convertie en énergie thermique. / Caloric effects (CEs), which are the phenomena that temperature variation is caused by entropy change, have been investigated for the novel system which might be able to replace conventional vapor compression refrigeration system. In the present thesis, the elastocaloric effect (ElCE) of natural rubber (NR) and terpolymer, poly(vinylidene fluoride-trifluoroethylene-chlorotrifluoroethylene) (P(VDF-TrFE-CTFE)), was focused. First of all, NR, which is an excellent candidate material for ElCE, was evaluated in cyclic deformation with different strain levels. It was found that NR exhibits temperature variation of around 4.0 °C. In general, the relation between stress/strain versus temperature variation is used to evaluate ElCE. The unsuitability of such evaluation method for NR was demonstrated. The evaluation method for ElCE which uses energy balance was then proposed. A linear relation between the temperature variation caused by ElCE and the applied mechanical energy by deformation was experimentally found. This fact verifies the suitability of the proposed method. Using the energy balance, besides, not only the conversion efficiency but also the influences of the Mullins effect and the strain-induced crystallization on the ElCE of NR were discussed. ElCE of P(VDF-TrFE-CTFE) was also evaluated in order to find out the potential of polymer. It was found that present terpolymer which is not one of the elastomers can also exhibit a large temperature variation, 2.1 °C, caused by ElCE if a large pre-stretch such as more than 1050 % is applied in advance. By comparison with other materials for ElCE, it was demonstrated that P(VDF-TrFE-CTFE) can be a high potential material for ElCE. It was also shown that P(VDF-TrFE-CTFE) converts most of the applied mechanical energy into the heat energy.

Le domaine du refroidissement est en constante expansion, le système actuel est basé sur la compression/décompression des fluides. Face aux problèmes environnementaux et économiques que ce système présente (natures des fluides frigorigènes et leurs recyclages, nuisances sonores et vibratoires, réglementations contraignantes), de nouvelles solutions techniques alternatives émergent. Ainsi ce travail de thèse porte sur de nouveaux systèmes de refroidissement basés sur les effets électrocalorique et magnétocalorique, respectivement présents dans des films minces de polymère fluoré et dans des composites à matrice polymère et à charges magnétocaloriques. A travers des caractérisations physico-chimiques, électriques, électrocaloriques et magnétocaloriques ces travaux se proposent d’identifier l’origine de l’effet électrocalorique dans des films minces de terpolymère P(VDF-TrFE-CTFE) ferroélectrique relaxeur, mais également d’étudier l’influence de la dispersion des particules magnétocaloriques La(Fe,Si)H dans une matrice polymère de poly(propylène) sur le phénomène magnétocalorique. De plus, dans le cadre de cette thèse, un appareil de mesure directe de l’effet électrocalorique a été développé avec le Dr. Basso de l’INRIM de Turin. La comparaison avec la méthode de mesure indirecte permet d’aborder ce phénomène d’un point de vue thermodynamique afin de faire le point sur la validité des hypothèses thermodynamiques utilisées dans le cas d’un polymère ferroélectrique relaxeur. / The cooling sector is in constant expansion, the current system is based on the compression/decompression of fluids. In front of environmental and economic problems of this system (nature of frigorigen fluids and their recycling, noise and vibration issues, restrictive regulations), new alternative technological solutions emerge. Thus this thesis provides new cooling systems based on the magnetocaloric and electrocaloric effects respectively present in thin films of fluoropolymer and composites with polymer matrix and magnetocaloric loads. Through physicochemical, electrical, electrocaloric and magnetocaloric characterizations, this work intends to identify the origin of electrocaloric effect in thin terpolymer films P(VDF-TrFE-CTFE) which is a ferroelectric relaxor, but also to study the influence of the magnetocaloric particles La(Fe,Si)H dispersion in a polymer matrix of poly(propylene) on the magnetocaloric phenomenon. In addition, as part of this thesis, a direct measurement device of the electrocaloric effect was developed with Dr. Basso from the INRIM of Turin. The comparison with the indirect measurement method comes up with this phenomenon from a thermodynamic point of view to take stock of the validity of thermodynamic assumptions used in the case of a ferroelectric polymer relaxor.