O objetivo deste trabalho foi avaliar a influência de diferentes aminas terciárias no grau de conversão, na contração de polimerização, na taxa de contração, na microdureza Knoop, na estabilidade de cor e na transmitância de luz de resinas experimentais, contendo, em peso, BisGMA e TEGDMA (3:1), 0,25% de canforquinona (CQ) e 1% de amina (DMAEMA, CEMA, DMPT, DEPT ou DABE). A influência de diferentes protocolos de fotoativação também foi investigada. O grau de conversão foi avaliado através de FTIR-ATR e a contração pelo método do disco aderido. A partir da diferenciação numérica dos dados de contração em relação ao tempo, obteve-se a taxa de contração de polimerização. A estabilidade de cor e a transmitância foram avaliadas em diferentes períodos de envelhecimento artificial. Os resultados foram avaliados pelos testes de ANOVA, Tukey e T3 de Dunnett (&#945; = 0,05). As propriedades estudadas variaram em função da amina. O grau de conversão e a contração de polimerização variaram na sequência: CQ < DEPT < DMPT &#8804; CEMA &#8776; DABE < DMAEMA. O grau de conversão e a contração também foram influenciados pelo protocolo de fotoativação, sendo observadas correlações positivas entre o grau de conversão e a contração e entre o grau de conversão e a taxa de contração. A cor variou na sequência: DMAEMA < DEPT < DMPT < CEMA < DABE. A transmitância variou na sequência: DEPT &#8776; DABE < DABE &#8776; DMPT &#8776; CEMA < DMPT &#8776; CEMA &#8776; DMAEMA, sendo mais evidente para o comprimento de onda de 400nm. Não foram observadas correlações entre o grau de conversão e as propriedades ópticas. A resina contendo DMAEMA apresentou maior grau de conversão, contração, taxa de contração e dureza, além de melhor estabilidade nas propriedades ópticas. / The aim of this work was to evaluate de influence of different tertiary amines on degree of conversion (DC), shrinkage-strain, shrinkage-strain-rate, Knoop microhardness, and colour and transmittance stabilities of experimental resins containing BisGMA / TEGDMA (3:1 wt), 0,25wt% camphorquinone, 1wt% amine (DMAEMA, CEMA, DMPT, or DABE). Different light-curing protocols were also evaluated. DC was evaluated with FTIR-ATR and shrinkage-strain with the bonded-disc method. Shrinkage-strain-rate data were obtained from numerical differentiation of shrinkage-strain data with respect to time. Colour stability and transmittance were evaluated during different periods of artificial aging, according to ISO 7491:2000. Results were evaluated with ANOVA, Tukey and Dunnetts T3 tests (&#945; = 0.05). The studied properties varied according to amines. DC and shrinkage-strain were maximum at the sequence: CQ < DEPT < DMPT &#8804; CEMA &#8776; DABE < DMAEMA. Both DC and shrinkage were also influenced by the curing protocol, with positive correlations between DC and shrinkage-strain and DC and shrinkage-strain-rate. Colour varied in the sequence: DMAEMA < DEPT < DMPT < CEMA < DABE. Transmittance varied in the sequence: DEPT &#8776; DABE < DABE &#8776; DMPT &#8776; CEMA < DMPT &#8776; CEMA &#8776; DMAEMA, being more evident at the wavelength of 400nm. No correlations between DC and optical properties were observed. The resin containing DMAEMA showed higher DC, shrinkage-strain, shrinkage-strain-rate and microhardness, in addition with better optical properties.

Thesis (M.S.)--University of South Florida, 2007. / Title from PDF of title page. Document formatted into pages; contains 80 pages. Includes bibliographical references.

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O objetivo deste trabalho foi avaliar a influência de diferentes aminas terciárias no grau de conversão, na contração de polimerização, na taxa de contração, na microdureza Knoop, na estabilidade de cor e na transmitância de luz de resinas experimentais, contendo, em peso, BisGMA e TEGDMA (3:1), 0,25% de canforquinona (CQ) e 1% de amina (DMAEMA, CEMA, DMPT, DEPT ou DABE). A influência de diferentes protocolos de fotoativação também foi investigada. O grau de conversão foi avaliado através de FTIR-ATR e a contração pelo método do disco aderido. A partir da diferenciação numérica dos dados de contração em relação ao tempo, obteve-se a taxa de contração de polimerização. A estabilidade de cor e a transmitância foram avaliadas em diferentes períodos de envelhecimento artificial. Os resultados foram avaliados pelos testes de ANOVA, Tukey e T3 de Dunnett (&#945; = 0,05). As propriedades estudadas variaram em função da amina. O grau de conversão e a contração de polimerização variaram na sequência: CQ < DEPT < DMPT &#8804; CEMA &#8776; DABE < DMAEMA. O grau de conversão e a contração também foram influenciados pelo protocolo de fotoativação, sendo observadas correlações positivas entre o grau de conversão e a contração e entre o grau de conversão e a taxa de contração. A cor variou na sequência: DMAEMA < DEPT < DMPT < CEMA < DABE. A transmitância variou na sequência: DEPT &#8776; DABE < DABE &#8776; DMPT &#8776; CEMA < DMPT &#8776; CEMA &#8776; DMAEMA, sendo mais evidente para o comprimento de onda de 400nm. Não foram observadas correlações entre o grau de conversão e as propriedades ópticas. A resina contendo DMAEMA apresentou maior grau de conversão, contração, taxa de contração e dureza, além de melhor estabilidade nas propriedades ópticas. / The aim of this work was to evaluate de influence of different tertiary amines on degree of conversion (DC), shrinkage-strain, shrinkage-strain-rate, Knoop microhardness, and colour and transmittance stabilities of experimental resins containing BisGMA / TEGDMA (3:1 wt), 0,25wt% camphorquinone, 1wt% amine (DMAEMA, CEMA, DMPT, or DABE). Different light-curing protocols were also evaluated. DC was evaluated with FTIR-ATR and shrinkage-strain with the bonded-disc method. Shrinkage-strain-rate data were obtained from numerical differentiation of shrinkage-strain data with respect to time. Colour stability and transmittance were evaluated during different periods of artificial aging, according to ISO 7491:2000. Results were evaluated with ANOVA, Tukey and Dunnetts T3 tests (&#945; = 0.05). The studied properties varied according to amines. DC and shrinkage-strain were maximum at the sequence: CQ < DEPT < DMPT &#8804; CEMA &#8776; DABE < DMAEMA. Both DC and shrinkage were also influenced by the curing protocol, with positive correlations between DC and shrinkage-strain and DC and shrinkage-strain-rate. Colour varied in the sequence: DMAEMA < DEPT < DMPT < CEMA < DABE. Transmittance varied in the sequence: DEPT &#8776; DABE < DABE &#8776; DMPT &#8776; CEMA < DMPT &#8776; CEMA &#8776; DMAEMA, being more evident at the wavelength of 400nm. No correlations between DC and optical properties were observed. The resin containing DMAEMA showed higher DC, shrinkage-strain, shrinkage-strain-rate and microhardness, in addition with better optical properties.

Le marché de la cosmétique est l’un des marché les plus porteur actuellement dans le monde. La population française utilise énormément ces produits pour son hygiène quotidienne. Ce sont les shampoings ou autre crème de soins. Pour protéger ces produits, depuis maintenant de nombreuses années, les fabricants ajoutent des agents conservateurs pour augmenter la durée de conservation, ou encore éviter certaines contaminations microbiennes après les contacts avec la peau. Ces dernières années ont également vu les mentalités des consommateurs évoluer et actuellement, ces derniers souhaiteraient des produits cosmétiques le plus naturel possible, sans ajouts de conservateurs. Dans ce contexte, il semble intéressant de travailler sur la protection de ces produits par d’autres moyens. En premier lieu, nous vient immédiatement à l’esprit, la protection par l’emballage. L’idée est de modifier les emballages actuels pour leur conférer des activités antimicrobiennes et ainsi les rendre protecteurs. L’étude présentée s’intéresse à certaines possibilités de mises en oeuvre et modifications de polymères pour apporter une activité antimicrobienne. Deux voies de fabrications ont été étudiées dans cette thèse. Une première a consisté en la réalisation de revêtements antimicrobiens et protecteurs à basse température. Cette technique a montré la possibilité de créer des couches antimicrobiennes par photo-polymérisation à partir de monomères méthacrylates renfermant les agents antimicrobiens. C’est cette couche finale qui va venir s’ajouter à certaines zones spécifiques des emballages finaux pour assurer la protection antimicrobienne du contenu.La seconde voie d’action a étudié une fabrication plus industrielle à haute température. Cette technologie a permis de créer par extrusion des granulés antimicrobiens avec des introductions d’actifs de différentes natures. Ceux sont ces granulés qui sont par la suite injectés sous la forme d’emballages. Pour cette voie d’action, l’idée n’est plus de protéger l’emballage via une couche antimicrobienne, mais de substituer certaines pièces de l’emballage constituées de polymères naturellement antimicrobiens. Ces travaux ont permis la réalisation d’une large gamme de matériaux antimicrobiens. Les différentes solutions étudiées ont également permis de réaliser des prototypes d’emballages, ceci en collaboration avec certaines entreprises partenaires du projet. Tous ces prototypes seront prochainement testés en conditions réelles d’utilisations, c’est-à-dire par des essais de mises en contact avec le consommateur d’un système complet, à savoir le produit cosmétique conditionné dans des emballages protecteurs. Ces tests devront permettre de vérifier si les solutions proposées pourraient aboutir à une adaptation sur une chaine industrielle pour une utilisation à grande échelle / Today the cosmetic market is one of the most popular in the world. French people use many these products everyday as for examples, creams or shampoos. In order to protect the cosmetic products, the manufacturers introduced during these last year additives or conservative agents in cosmetic products to increase the shelf life or avoid a microbial contamination after a direct contact with the skin of consumers. However, recent years have also revealed that the consumer mindsets evolve and now, they would like cosmetics more natural, without addition of additives. In this context, it was interesting to work on the cosmetics protection by other ways. Firstly, we think immediately to the protection by use of packaging. The objective is to modify the current packaging to bring an antimicrobial activity and protect the cosmetics. This work presents different technologies of fabrication and modification of polymers to get an antimicrobial activity. For this, two techniques were studied. A first technology has consisted to develop antimicrobial coating at low temperature. This way has demonstrated possibilities of creation by photo-polymerization under UV radiations. Initially, the antimicrobial agents were introduced in liquid monomers before the polymerization and the fabrication of polymer networks. The final coatings were finally destiny to be added on specific areas of packaging, generally in contact with the consumers and prevent all risks of microbial contaminations from the products. The second technology has studied a way of polymer fabrication more industrial at high temperature. The technique has consisted to create antimicrobial pellets by extrusion with introductions of different natures of additives. The obtain pellets were injected at the end to fabricate certain pieces of the final packaging. This work has allowed the realization of a large range of antimicrobial materials. All the studied solutions have been used to fabricate prototype packaging in collaboration with partner companies of the project. All these prototypes will be tested by antimicrobial tests in real conditions of uses. If these tests prove successful, it will be possible to envisage an industrialization step

Indiana University-Purdue University Indianapolis (IUPUI) / A provisional restoration must fulfill biologic, mechanical, and esthetic requirements. These prostheses should provide comfort, pulp protection, positional stability, occlusal function, hygiene access, esthetics, strength and retention. Methyl-methacrylate acrylic has assumed many appli¬cations in the field of restorative dentistry. However, the material still has deficiencies, such as polymerization shrinkage, pulpal damage associated with exothermic polymerization and susceptibility to fracture. Bis-GMA composites, Bis-acryl composites and visible light-cured urethane dimethacrylate resins have been developed to address these issues. The purpose of this study was to compare the mechanical properties of provisional restorations made from composite resins (Protemp Plus, Luxatemp Solar, Radica, Protemp Crown) to those made of the traditional methacrylate resins (Jet, Snap, High Impact). Six groups of samples, two groups from methacrylate and four groups from composite based materials, were fabricated. Samples from each group were evaluated for microhardness (n=10), flexural strength and flexural modulus (n=20) according to ISO 4049, and fracture toughness (n=20) according to ISO 13586. From each of the six groups, ten samples were tested for flexural strength, flexural modulus and fracture toughness and 5 samples were tested for microhardness. These tests were done after storing at 37°C in a distilled water solution for 7 days followed by thermal cycling (2500 cycles, 5-55°C, 45 s. dwell). Identical sets of samples from each group were used as controls; these were tested after storing for 24 hours in dry conditions. The results were analyzed by two-way ANOVA with material type and aging conditions as the two main variables. Significance level was set at p=0.05. For flexural strength and flexural modules, the higher values were obtained for Radica. Protemp plus (7 days) and Radica (24h) had the highest fracture toughness value. Protemp crown showed the highest surface hardness. The mechanical properties of composite resin were superior.

Phosphonium ions readily compare to ammonium ions in regards to their aggregate characteristics, thermal stability, and antibacterial activity. Ionic aggregation in phosphonium-based polymers provides thermoreversible crosslinks, ideal for reversible self-assembly, self-healing, and smart response. In polymers, these ionic functionalities aggregate, providing improved moduli, and altering the size and structure of ionic aggregates regulates polymer melt processability. This dissertation highlights phosphonium-based chemistry for the synthesis of novel step-growth ionomers and structure-property relationships in ionic polymers. The synthesis of phosphonium endcapping reagents for melt polyester reactions afforded a thermally stable ionic functionality that controlled molecular weight. Weak association was present with phosphonium ions at low ion concentrations below 7.7 mole %. The use of novel ionic bisacetoacetate monomers in the formation of networks from Michael addition reactions led to the synthesis of ionic networks with increased and broadened glass transitions and improved tensile stresses at break and strains at break compared to those in the non-ionic networks. The first electrospun fibers from Michael addition crosslinking reactions are reported, and equilibrium ionic liquid uptake experimental results indicated that ionic functional networks absorb close to three times the amount of ionic liquid as non-ionic, poly(ethylene glycol)-based films. Chain-extending polyurethanes with a phosphonium diol and subsequently varying the hard segment content led to changes in ionic aggregation, crystallinity, and thermal transitions in the polymers. Additionally, novel phosphonium-based methacrylate monomers incorporated into diblock copolymers with styrene exhibited microphase separation. Overall, the inclusion of phosphonium ions pendant to or in the main chain of various types of polymers led to changes in morphology, improved tensile properties, enhanced moduli, broadened transitions, changes in crystalline melting points, changes in solubility, and appearance of ionic aggregation. / Ph. D.

La necesidad de polímeros bioestables para fabricación de implantes protésicos queda patente, entre otros indicadores, por la proliferación de dispositivos actualmente comercializados. La caracterización físico-química así como la respuesta biológica de un conjunto de materiales poliméricos bioestables es el objetivo último de esta tesis. En este trabajo se han sintetizado diferentes materiales poliméricos de la familia de los acrilatos y metacrilatos variando sutilmente sus características superficiales, como el grado de hidrofilia o la distribución de cargas eléctricas. El procedimiento consistió en la copolimerización via radical de acrilato de etilo, EA, acrilato de 2-hidroxietilo, HEA, y ácido metacrílico, MAAc. Se ha caracterizado los materiales en estado seco y en presencia de diferentes contenidos de agua mediante calorimetría diferencial de barrido, DSC, análisis dinámico-mecánico, DMA, microscopía de fuerza atómica, AFM, análisis dieléctrico, DRS, contenido de agua en equilibrio, EWC, y energía superficial, SE, persiguiendo el objetivo de dilucidar si el agua es capaz de inducir cambios conformacionales en las cadenas poliméricas que den lugar a una separación de fases. Sobre los materiales en forma de scaffold poroso con poros esféricos interconectados se ha cultivado fibroblastos y endoteliales. La compatibilidad de las células endoteliales se midió en términos de viabilidad celular y la adecuada diferenciación endotelial y su funcionamiento. Se han realizado cultivos de células endoteliales humanas primarias, HUVEC, y se ha determinado si su morfología y función se vio afectada por el material. Se examinó la adhesión y proliferación de las mismas, así como un marcador importante de activación endotelial, la E-selectina. Se evaluó si se mantuvieron los fenotipos endoteliales normales y sus funciones observadas in vivo mediante análisis de los contactos célula-célula y la regulación de la expresión génica del marcador de activación E-selectina cuando se añadió un estímulo (LPS). Además, como posible aplicación de estos materiales en una prótesis de córnea artificial, y dado que los fibroblastos del estroma de la córnea (es decir, los queratocitos) son de relevancia en la cicatrización de la córnea se determinó cómo afectaba la hidrofilicidad del substrato a la adhesión celular de la línea de fibroblastos humanos MRC-5, como modelo celular para estudiar la disposición del citoesqueleto tras la adhesión a los diferentes soportes mediante la detección de F-actina. Asimismo, se ha sembrado células epiteliales evaluando su comportamiento/funcionamiento celular ya que uno de los requisitos esenciales para que un implante de queratoprótesis tenga éxito es que se cree y mantenga una capa de células epiteliales que impidan entrar a las bacterias al interior del ojo y permita la difusión la capa lagrimal de manera estable en el tiempo. Así, se han analizado parámetros celulares como adhesión, proliferación y viabilidad de una línea de células epiteliales de conjuntiva humana, NHC, cultivada sobre substratos poliméricos con diferentes grados de hidrofilia y cargas eléctricas superficiales buscando qué grado de hidrofilicidad permite la epitelización del substrato y podría darle al material flexibilidad y la hidrofilicidad necesaria para un mejor contacto con los párpados y lágrima. Los resultados obtenidos se han correlacionado con la adsorción y conformación de una proteína de la matriz extracelular, la fibronectina. / Campillo Fernández, AJ. (2014). Polímeros bioestables para fabricación de implantes protésicos: caracterización físico-química y respuesta biológica in vitro [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/44232 / Premios Extraordinarios de tesis doctorales

Photo-initiated reactions involve the use of ultraviolet (UV) or visible light radiation to effect chemical transformations. Some of the advantages of photo-initiated reactions over thermal or high pressure reactions include mild reaction conditions like ambient temperature and pressure, good control over the reaction by the simple switching on/off the light source, and faster reaction kinetics. Usually, semiconductor photocatalysts or oxidizing agents are used to enhance the rate of photo reactions. “Photocatalysis” involves the generation of valence band holes and conduction band electrons by the band gap excitation of a semiconductor photocatalyst. These charge carriers produce reactive hydroxyl and superoxide radicals, which mediate oxidation and reduction reactions. However, the oxidizing agents are decomposed by the incident radiation to generate reactive radicals, which accelerate the photo reaction. Today, photocatalysis and photo-oxidative reactions are widely being practiced for environmental pollution abatement, synthesis of fine chemicals, synthesis of polymers, generation of hydrogen as a clean energy carrier, and in anti-fogging and self-cleaning surface treatments. The present investigation focuses on elucidating the mechanism and kinetics of environmentally and synthetically relevant photo-initiated reactions for a better understanding of the fundamental aspects of the photo processes. The different photo-initiated reactions studied in this dissertation can be grouped under the broad categories of (i) photocatalytic degradation of organic compounds like dyes and phenols, and reduction of metal ions, (ii) photocatalytic degradation of polymers, (iii) selective photocatalytic oxidation of cyclohexane, (iv) sonophotocatalytic degradation of dyes, (v) photopolymerization, and (vi) sonophotooxidative degradation of polymers. Nano-sized TiO2, synthesized by solution combustion technique (henceforth denoted as CS TiO2), was used as the photocatalyst for most of the above reactions, except for the last two polymer reactions, where organic initiators were used. Invariably, the photocatalytic activity of CS TiO2 was compared with the commercially available Degussa P-25 TiO2 (DP25). Based on the experimental results, detailed mechanisms were proposed for the different reactions, kinetic models were derived, and the rate coefficients signifying the importance of the underlying reaction steps were evaluated. Pd2+ substituted and Pd0 impregnated TiO2 were synthesized by solution combustion and reduction techniques, respectively, and characterized by powder XRD, XPS, TEM, BET surface area, UV/visible, TGA, FT-IR and photoluminescence measurements. While the above catalysts are known to be more active compared to CS TiO2 for the gas phase NO reduction and NO decomposition reactions, it was found in this study, that these catalysts exhibit lower activity for the degradation of organic compounds like dyes, phenol and 4-chlorophenol, in the aqueous phase. The decrease in activity was correlated with a reduction in surface area and photoluminescence intensity of these catalysts, compared to CS TiO2. Ag+ substituted (Ag sub) and Ag0 impregnated (Ag imp) nano-TiO2 were synthesized by solution combustion and reduction techniques, respectively, and characterized by the above standard measurements. These catalysts were used for the photodegradation of dyes, and the selective photooxidation of cyclohexane to cyclohexanone. For the photocatalytic degradation of dyes, unsubstituted CS TiO2 exhibited the highest activity, followed by 1% Ag imp and 1% Ag sub. However, for the photooxidation of cyclohexane, the total conversion of cyclohexane and the selectivity of cyclohexanone followed the order: 1% Ag sub > DP-25 > CS TiO2 > 1% Ag imp. The kinetics of photodegradation of the dyes and the photooxidation of cyclohexane was modeled using Langmuir-Hinshelwood rate equation, and a free radical mechanism, respectively. This study proves that the photoactivity of a catalyst is not solely determined by a single physical property, but rather by a number of variables including the surface area, band gap, surface hydroxyl content, oxide ion vacancy and surface charge of the catalyst. The photocatalytic degradation of five anionic, eight cationic and three solvent dyes, containing different functional groups, was evaluated. The degradation of the dyes was quantified using the initial rate of decolorization and overall percent mineralization. The decolorization of the anionic dyes with CS TiO2 followed the order: Indigo Carmine > Eosin Y > Amido Black 10B > Alizarin Cyanine Green > Orange G. The decolorization of the cationic dyes with DP-25 followed the order: Malachite Green > Pyronin Y > Rhodamine 6G > Azure B > Nile Blue Sulfate > Auramine O ≈ Acriflavine ≈ Safranin O. CS TiO2 exhibited higher rates of decolorization and mineralization for all the anionic dyes, while DP-25 was better in terms of decolorization for most of the cationic dyes. The solvent dyes exhibited adsorption dependent decolorization. The observed results were rationalized based on the molecular structure and degradation pathway of the dyes. The simultaneous photocatalytic degradation of phenolic compounds like phenol and 4-nitrophenol, and the reduction of metal ions like copper (Cu2+) and chromium (Cr6+) were studied. It was found that the presence of phenol accelerated the reduction of Cu2+ to Cu+, and the presence of phenol and 4-nitrophenol accelerated the adsorption of Cr6+ onto CS TiO2. A detailed dual-cycle, multi-step reaction mechanism was proposed for the simultaneous degradation and reduction, and a model was developed using the network reduction technique. The kinetic rate constants in the model were evaluated for the systems studied. The simultaneous UV and ultrasound (US) degradation of anionic dyes was carried out in presence of CS TiO2. The rates of degradation and mineralization of the dyes were higher for the sonophotocatalytic process compared to the individual photo-and sonocatalytic processes. The effect of dissolved gases and US intensity on the sonophotocatalytic degradation of the dyes was evaluated. A dual-pathway network mechanism of sonophotocatalytic degradation was proposed for the first time, and the rate equations were modeled using the network reduction technique. The kinetic rate coefficients of the individual steps were evaluated for all the systems by fitting the model with the experimental data. Eosin Y and Fluorescein dye sensitized visible light degradation of phenol, 4chlorophenol, 2,4-dichlorophenol and 2,4,6-trichlorophenol was studied. A detailed mechanism of sensitized degradation was proposed, and a mechanistic model for the rate of degradation of the phenolic compound was derived by using the pyramidal network reduction technique to evaluate the rate coefficients. An important conclusion of this study indicates that at low initial dye concentrations, the rate of degradation of the phenolic compound is first order in the concentration of the dye, while at high initial dye concentrations, the rate is first order in the concentration of the phenolic compound. The different phenolic and dye intermediates that were formed during degradation were identified by mass spectrometry, and a most probable pathway of degradation was proposed. The solution photopolymerization of methyl-, ethyl-, butyl-and hexylmethacrylates in presence of benzoyl peroxide as the initiator was studied. The effect of initiator and monomer concentrations on the time evolution of polymer concentration, number average molecular weight (Mn) and polydispersity (PDI) was examined. The reversible chain addition and β-scission, and primary radical termination steps were included in the mechanism along with the classical initiation, propagation and termination steps. The rate equations were derived using continuous distribution kinetics and solved numerically to fit the experimental data. The model predicted the instantaneous increase of Mn and PDI of the polymers to steady state values. The rate coefficients exhibited a linear increase with the size of the alkyl chain of the alkyl methacrylates. Poly(acrylamide-co-acrylic acid) copolymers of different compositions were synthesized and characterized. The copolymers were statistical with a relatively high percentage of acrylamide units, as determined by 13C-NMR. The aqueous phase photolytic and photocatalytic degradation of the copolymers and the homopolymers was conducted. The degradation was modeled using continuous distribution kinetics. The degradation followed a two step mechanism, wherein the rapid first step comprised of the scission of weak acrylic acid units along the chain, which was followed by the breakage of the relatively strong acrylamide units. The rate constants for the weak and strong links followed a linear trend with the percentage of acrylic acid and acrylamide in the copolymer, respectively. The photocatalytic degradation of the copolymers of methyl methacrylate with butyl methacrylate (MMA-BMA), ethyl acrylate (MMA-EA) and methacrylic acid (MMA-MAA) was carried out in toluene. The copolymers and the corresponding homopolymers degraded randomly along the chain. The degradation rate coefficient was determined using continuous distribution kinetics. The time evolution of the hydroxyl and hydroperoxide stretching vibration in the FT-IR spectra of the copolymers indicated that the degradation rate follows the order: MMA-MAA > MMA-EA > MMA-BMA. The photodegradation rate coefficients were compared with the activation energy of pyrolytic degradation. The observed contrast in the order of thermal stability compared to the photostability of these copolymers was attributed to the two different mechanisms governing the scission of the polymers and the evolution of the products. The mechano-chemical degradation of poly(methyl methacrylate), poly(ethyl methacrylate) and poly(n-butyl methacrylate) using US and UV radiation, in presence of benzoin as the photoinitiator, was carried out. A degradation mechanism that included the decomposition of the initiator, generation of polymer radicals by hydrogen abstraction of the initiator radicals, and reversible chain transfer between the stable polymer and the polymer radicals, was proposed. The mechanism assumed mid-point chain scission due to US and random chain scission due to UV radiation. The steady state evolution of PDI was successfully predicted by the continuous distribution kinetics model. The rate coefficients of polymer scission due to US and UV radiation exhibited a linear increase and decrease with the size of the alkyl group of the poly(alkyl methacrylate)s, respectively.