Étude de la représentation du curé dans deux films québécois La petite Aurore l'enfant martyre (1952) et Aurore (2005)

Ce mémoire porte sur la représentation du curé dans les films La petite Aurore l'enfant martyre (Jean-Yves Bigras, 1952) et Aurore (Luc Dionne, 2005). L'objectif principal est d'identifier l'image que l'on présente du curé dans ces deux oeuvres. L'étude de cette représentation permet de cerner les discours portés par ces deux films à travers le personnage du curé et d'apprécier dans quelle mesure ces discours filmiques témoignent du caractère de la société québécoise à deux époques déterminées, soit les années 1950 et les années 2000. Inscrite dans le champ des études culturelles, la recherche se fonde sur quatre axes théoriques principaux : la représentation, l'interprétation, la mythologie et l'analyse filmique. Les travaux de Stuart Hall, d'Umberto Eco et de Roland Barthes constituent le cadre théorique. L'approche de l'analyse de contenu s'inspire des travaux de Laurence Bardin et l'analyse filmique, de ceux de Jean Mitry, d'Anne Goliot-Lété et de Francis Vanoye, entre autres. La procédure de recherche consiste dans le découpage des éléments constitutifs de chaque film en plans, séquences et extraits, de manière à déconstruire les récits filmiques et à faire émerger les facteurs signifiants susceptibles de permettre de reconstituer le sens à travers la reconstruction du rôle du curé et la caractérisation du personnage dans chacun des films. La démarche d'interprétation s'appuie sur une série de thèmes sous lesquels se classent, en opposition souvent, les attributs des deux personnages, comme l'apparence générale, l'intégration au milieu, l'intellectualité, la figure d'autorité, le conformisme et la responsabilité. L'hypothèse principale formulée dans le cadre de la problématique se trouve validée. La représentation du curé dans le film de 1952 offre une image idéalisée du « bon curé », laquelle est conforme au discours dominant de son époque de production. Dans le film de 2005, on délaisse plutôt l'image idéalisée pour revêtir le curé d'attributs négatifs et le rendre responsable, en grande partie, du drame vécu par Aurore. De plus, les trois hypothèses secondaires ont pu aussi être validées : la représentation du curé en 2005 est liée à une plus grande sensibilité au phénomène de la maltraitance des enfants et au besoin d'en identifier les responsables; le transfert de responsabilité vers le curé semble le reflet de reproches adressés par la société québécoise au clergé pour des fautes du passé et la représentation péjorative du curé de 2005, où l'on insiste sur son caractère froid et distant, ne choque plus personne. Porteuse de plusieurs mythes, dont certains rejoignent les fondements de l'identité québécoise, l'histoire d'Aurore fait partie intégrante du patrimoine culturel. Les relectures de cette triste affaire au fil des ans traduisent aussi les changements qui marquent la société québécoise, en particulier dans son rapport au clergé et à la religion.

L'orientation et la propriété de mémoire de forme des polymères cristallins liquides à chaînes latérales covalents et supramoléculaires

In many studies of the side-chain liquid crystalline polymers (SCLCPs) bearing azobenzene mesogens as pendant groups, obtaining the orientation of azobenzene mesogens at a macroscopic scale as well as its control is important, because it impacts many properties related to the cooperative motion characteristic of liquid crystals and the trans-cis photoisomerization of the azobenzene molecules. Various means can be used to align the mesogens in the polymers, including rubbed surface, mechanical stretching or shearing, and electric or magnetic field. In the case of azobenzene-containing SCLCPs, another method consists in using linearly polarized light (LPL) to induce orientation of azobenzene mesogens perpendicular to the polarization direction of the excitation light, and such photoinduced orientation has been the subject of numerous studies. In the first study realized in this thesis (Chapter 1), we carried out the first systematic investigation on the interplay of the mechanically and optically induced orientation of azobenzene mesogens as well as the effect of thermal annealing in a SCLCP and a diblock copolymer comprising two SCLCPs bearing azobenzene and biphenyl mesogens, respectively. Using a supporting-film approach previously developed by our group, a given polymer film can be first stretched in either the nematic or smectic phase to yield orientation of azobenzene mesogens either parallel or perpendicular to the strain direction, then exposed to unpolarized UV light to erase the mechanically induced orientation upon the trans–cis isomerization, followed by linearly polarized visible light for photoinduced reorientation as a result of the cis–trans backisomerization, and finally heated to different LC phases for thermal annealing. Using infrared dichroism to monitor the change in orientation degree, the results of this study have unveiled complex and different orientational behavior and coupling effects for the homopolymer of poly{6-[4-(4-methoxyphenylazo)phenoxy]hexyl methacrylate} (PAzMA) and the diblock copolymer of PAzMA-block- poly{6-[4-(4-cyanophenyl) phenoxy]hexyl methacrylate} (PAzMA-PBiPh). Most notably for the homopolymer, the stretching-induced orientation exerts no memory effect on the photoinduced reorientation, the direction of which is determined by the polarization of the visible light regardless of the mechanically induced orientation direction in the stretched film. Moreover, subsequent thermal annealing in the nematic phase leads to parallel orientation independently of the initial mechanically or photoinduced orientation direction. By contrast, the diblock copolymer displays a strong orientation memory effect. Regardless of the condition used, either for photoinduced reorientation or thermal annealing in the liquid crystalline phase, only the initial stretching-induced perpendicular orientation of azobenzene mesogens can be recovered. The reported findings provide new insight into the different orientation mechanisms, and help understand the important issue of orientation induction and control in azobenzene-containing SCLCPs. The second study presented in this thesis (Chapter 2) deals with supramolecular side-chain liquid crystalline polymers (S-SCLCPs), in which side-group mesogens are linked to the chain backbone through non-covalent interactions such as hydrogen bonding. Little is known about the mechanically induced orientation of mesogens in S-SCLCPs. In contrast to covalent SCLCPs, free-standing, solution-cast thin films of a S-SCLCP, built up with 4-(4’-heptylphenyl) azophenol (7PAP) H-bonded to poly(4-vinyl pyridine) (P4VP), display excellent stretchability. Taking advantage of this finding, we investigated the stretching-induced orientation and the viscoelastic behavior of this S-SCLCP, and the results revealed major differences between supramolecular and covalent SCLCPs. For covalent SCLCPs, the strong coupling between chain backbone and side-group mesogens means that the two constituents can mutually influence each other; the lack of chain entanglements is a manifestation of this coupling effect, which accounts for the difficulty in obtaining freestanding and mechanically stretchable films. Upon elongation of a covalent SCLCP film cast on a supporting film, the mechanical force acts on the coupled polymer backbone and mesogenic side groups, and the latter orients cooperatively and efficiently (high orientation degree), which, in turn, imposes an anisotropic conformation of the chain backbone (low orientation degree). In the case of the S-SCLCP of P4VP-7PAP, the coupling between the side-group mesogens and the chain backbone is much weakened owing to the dynamic dissociation/association of the H-bonds linking the two constituents. The consequence of this decoupling is readily observable from the viscoelastic behavior. The average molecular weight between entanglements is basically unchanged in both the smectic and isotropic phase, and is similar to non-liquid crystalline samples. As a result, the S-SCLCP can easily form freestanding and stretchable films. Furthermore, the stretching induced orientation behavior of P4VP-7PAP is totally different. Stretching in the smectic phase results in a very low degree of orientation of the side-group mesogens even at a large strain (500%), while the orientation of the main chain backbone develops steadily with increasing the strain, much the same way as amorphous polymers. The results imply that upon stretching, the mechanical force is mostly coupled to the polymer backbone and leads to its orientation, while the main chain orientation exerts little effect on orienting the H-bonded mesogenic side groups. This surprising finding is explained by the likelihood that during stretching in the smectic phase (at relatively higher temperatures) the dynamic dissociation of the H-bonds allow the side-group mesogens to be decoupled from the chain backbone and relax quickly. In the third project (Chapter 3), we investigated the shape memory properties of a S-SCLCP prepared by tethering two azobenzene mesogens, namely, 7PAP and 4-(4'-ethoxyphenyl) azophenol (2OPAP), to P4VP through H-bonding. The results revealed that, despite the dynamic nature of the linking H-bonds, the supramolecular SCLCP behaves similarly to covalent SCLCP by exhibiting a two-stage thermally triggered shape recovery process governed by both the glass transition and the LC-isotropic phase transition. The ability for the supramolecular SCLCP to store part of the strain energy above T[subscript g] in the LC phase enables the triple-shape memory property. Moreover, thanks to the azobenzene mesogens used, which can undergo trans-cis photoisomerization, exposure the supramolecular SCLCP to UV light can also trigger the shape recovery process, thus enabling the remote activation and the spatiotemporal control of the shape memory. By measuring the generated contractile force and its removal upon turning on and off the UV light, respectively, on an elongated film under constant strain, it seems that the optically triggered shape recovery stems from a combination of a photothermal effect and an effect of photoplasticization or of an order-disorder phase transition resulting from the trans-cis photoisomerization of azobenzene mesogens.