Thesis (Ph. D.)--Lehigh University, 1997. / Includes vita. Includes bibliographical references.

The use of polymer brushes (long polymer chains anchored at their end to a surface or an interface) as a robust approach to control surface properties has generated significant interest in recent years. The stretched conformation of polymer brushes results in unique aggregation, phase, and dynamic behaviors, therefore, they have been used to stabilize colloidal particles and applied in numerous innovative biomedical applications: targeted magnetic hyperthermia, targeted drug delivery, and genotyping. The main goal of this thesis is to shed light on the key factors that affect the formation of these brushes in solution on solid surfaces. In Chapter 3, attenuated total reflectance infrared spectroscopy (ATR-IR) is used to directly measure the rates of the copper-catalyzed azide-alkyne cycloaddition (CuAAC) reactions between alkyne-terminated polystyrene and poly(n-butyl acrylate) and azide-functional substrates in the good solvent DMF. Four regimes of behavior are observed: initially, the reaction rate is diffusion-controlled scaling with t^1/2; in the crossover regime at the onset of chain overlap, the rate scales with ln(t); the rate then accelerates briefly; and finally, in the terminal or penetration-limited regime, the logarithm of areal density scales linearly with time. Kinetic behavior in the diffusion-limited, crossover, and penetration-limited regimes corresponds well to the predictions of Ligoure and Leibler. The blob model suggests that the acceleration in rate is due to lateral chain contraction during the mushroom to brush transition. A theory is presented which predicts that the areal density at saturation should scale as Σsaturation ∼ MW^1.2 for good solvents, and experimentally we find MW^(−0.93±0.04) scaling. In Chapter 4, the effect of symmetry of the CuAAC reaction is investigated for the reaction of end-functional polystyrene and solid surfaces modified with self-assembled monolayers (SAMs). The polymer grafting density on azide-functional substrates is about two times higher than the polymer density on alkyne-functional surfaces. This asymmetry in the reaction density is caused by the difference in the mobility of the alkyne groups between the two systems. While the reaction stoichiometry requires one alkyne and one azide, the reaction mechanism involves two alkyne groups and one azide group in the formation of a stable triazole ring. When the alkyne groups are on the surfaces, their mobility is significantly reduced, preventing the formation of the triazole rings and consequently decreasing the amount of polymer grafted. Increasing the alkynes’ mobility by either extending the thickness of the alkyne monolayer or adding free 1-pentyne improves the polymer density on alkyne-functional silica substrates. The presence of free 1-pentyne also increases the polymer density on alkyne-functional wafers containing a preexisting polymer brush. This study shows that the placement of each functional group in the CuAAC reaction is important in surface modification applications. In Chapter 5, a universal model to quantify the amount of tails vs. loops during brush formation of telechelic polymers is proposed. This model involves the synthesis of telechelic polymers bearing a degradable unit in the middle of each chain via ATRP. Several reaction schemes are suggested for the synthesis of the required bi-functional ATRP initiators with degradable units. The amount of singly (tails) vs. doubly (loops) bound chains is quantified by comparing the brush heights, measured by ellipsometry, before and after degradation.

Telechelic associating polymer networks consist of polymer chains terminated by endgroups that have a different chemical composition than the polymer backbone. When dissolved in a solution, the endgroups cluster together to form aggregates. At low temperature, a strongly connected reversible network is formed and the system behaves like a gel. Telechelic networks are of interest since they are representative for biopolymer networks (e.g. F-actin) and are widely used in medical applications (e.g. hydrogels for tissue engineering, wound dressings) and consumer products (e.g. contact lenses, paint thickeners). In this thesis such systems are studied by means of a molecular dynamics/Monte Carlo simulation. At first, the system in rest is studied by means of graph theory. The changes in network topology upon cooling to the gel state, are characterized. Hereto an extensive study of the eigenvalue spectrum of the gel network is performed. As a result, an in-depth investigation of the eigenvalue spectra for spatial ER, scale-free, and small-world networks is carried out. Next, the gel under the application of a constant shear is studied, with a focus on shear banding and the changes in topology under shear. Finally, the relation between the gel transition and percolation is discussed.

This thesis begins with a brief overview of supramolecular chemistry and selfassembly and simple examples derived from Nature that provide the motivation for the work presented here. The concept of a synthetic noncovalent toolbox is then introduced. The discussion then focuses more explicitly on side-chain and main-chain functionalized motifs and the methodologies employed in supramolecular polymer functionalization. The primary hypothesis of the thesis is that the combination of supramolecular strategies, ring-opening metathesis polymerization, and a well-understood toolbox of functionalities capable of noncovalent interactions, comprises a method for generating bioinspired materials. This hypothesis was tested by synthesizing unique functionalized supramolecular polymers that allowed for a detailed understanding of the orthogonality of noncovalent interactions and how such interactions can begin to mimic the complexity of functional biomaterials. The strategies and methods discussed in the synthesis of these bioinspired materials are divided into three chapters: (1) an exploration of the self-sorting phenomena between two non-complementary pairs of hydrogen bonds along polymer side-chains, (2) the extension of the self-sorting concept to include a metal coordination moiety, and (3) the side-chain functionalization strategies of chapters 2 and 3 in combination with the main-chain ROMP methodologies discussed in chapter 1 to form orthogonally self-assembled multifunctional block copolymers. The main results of this thesis include the results that multifunctional block copolymers can be fashioned via ROMP, functionalized in both the main- and side-chains, and self-assembled in an orthogonal fashion. In addition, these studies have found that self-sorting between pairs of non-complementary hydrogen bonding motifs can occur in supramolecular synthetic systems, that the interactions are extremely solvent dependent and that these interactions can result in unexpected phenomena. These results demonstrate the importance of a fully understood toolbox for the rapid development of supramolecular materials. The knowledge derived from this toolbox and presented in chapters 2, 3, and 4, allows for the careful selection of compounds for cleverly designed self-assembly materials inspired by Nature. Finally, conclusions are drawn to the success of the synthetic toolbox and the various strategies presented herein, and potential future directions are discussed.

The synthesis of dipyridyl functionalized polysulfones with improved hydrophilicity, enhanced membrane morphology and excellent ATRP polymeric ligand properties was conducted by the following method: (a) the formation of lithiated polysulfone from unmodified polysulfone and the subsequent reaction with 2,2'-vinylidenedipyridine in tetrahydrofuran at -78 oC under argon atmosphere to afford the corresponding dipyridyl functionalized polysulfone. The stoichiometry of the reaction affects the degree of functionalization of the product. When equimolar amounts of 2,2'-vinylidenedipyridine are added to the lithiated polysulfone, the degree of functionalization obtained was 45%. However, the addition of 10% and 20% molar excess of 2,2'-vinylidenedipyridine to the corresponding lithiated polysulfone produced dipyridyl functionalized polysulfones with degrees of functionalization of 80% and 95%, respectively; and (b) the membranes obtained from unmodified polysulfone as well as dipyridyl functionalized polysulfones were characterized by atomic force microscopy, scanning electron microscopy, pure water permeation measurements and contact angle measurements. Amine chain end functionalized polystyrene and poly(methyl methacrylate) were prepared by Atom Transfer Radical Polymerization (ATRP) methods as follows: (a) •-Aminophenyl functionalized polystyrene was prepared in quantitative yields by ATRP methods using a new primary amine functionalized initiator adduct, formed in situ by the reaction of 1-(4-aminophenyl)-1-phenylethylene and (1-bromoethyl)benzene in the presence of copper (I) bromide/2,2'-bipyridyl as catalyst in diethyl ether at 110 oC, for the polymerization of styrene.(b) New •-bis(aminophenyl) and •,ω-tetrakis(aminophenyl) functionalized polymers were prepared in quantitative yields by the ATRP method using the following synthetic strategy: (i) the initiation of styrene polymerization with a new primary diamine functionalized initiator adduct, generated in situ by the reaction of stoichiometric amounts of 1,1-bis(4-aminophenyl)ethylene with (1-bromoethyl)benzene in the presence of copper (I) bromide/2,2'-bipyridyl as catalyst, afforded •-bis(aminophenyl) functionalized polystyrene; and (ii) •-bis(aminophenyl) functionalized poly(methyl methacrylate) was prepared by the ATRP method using the primary diamine functionalized initiator adduct as initiator for methyl methacrylate polymerization; and (iii) well defined •,ω-tetrakis(aminophenyl) functionalized polystyrene was prepared by the post ATRP chain end modification reaction of •-bis(aminophenyl) functionalized polystyrene with 1,1-bis(4-aminophenyl)-ethylene at the completion of the polymerization reaction. (c) Similarly, •-bis(4-dimethylaminophenyl) functionalized polystyrene was prepared by using a new tertiary diamine functionalized initiator adduct, formed in situ by treatment of equimolar amounts of 1,1-bis[(4-dimethylamino)phenyl]-ethylene with (1-bromoethyl)benzene in the presence of copper (I) bromide/2,2'-bipyridyl as the catalyst in diphenyl ether at 110 oC for the initiation of styrene polymerization by the ATRP method. Furthermore, the ATRP of methyl methacrylate, initiated by the new tertiary diamine functionalized initiator adduct, produced •-bis(4-dimethylaminophenyl) functionalized poly(methyl methacrylate). In addition, •,ω-tetrakis(4-dimethylaminophenyl) functionalized polystyrene was synthesized via a post ATRP chain end modification reaction of •-bis(4-dimethylaminophenyl) functionalized polystyrene with equimolar amounts of 1,1-bis[(4-dimethylamino)phenyl]ethylene at the completion of the polymerization process. vi Quantitative yields of the different amine functionalized polymers with predictable number average molecular weights (Mn = 1.3 x 103 – 16.4 x103 g/mol), narrow molecular weight distributions (Mw/Mn = 1.03 – 1.29) and controlled chain end functionality were obtained. Polymerization kinetics data was employed to determine the controlled/living character of each ATRP reaction leading to the formation of the different amine chain end functionalized polymers. The polymerization processes were monitored by gas chromatographic analyses. Polymerization kinetics measurements for all reactions show that the polymerizations follow first order rate kinetics with respect to monomer consumption. The number average molecular weight of the amine functionalized polymers increases linearly with percentage monomer conversion and polymers with narrow molecular weight distribution were obtained. The ATRP of styrene, catalyzed by a novel dipyridyl functionalized polysulfone/CuBr supported catalyst system, afforded well defined polystyrene with predictable number average molecular weight and narrow molecular weight distribution in a controlled/living free radical polymerization process. The substituted 1,1-diphenylethylene initiator precursor derivatives and the functionalized polymers were characterized by nuclear magnetic resonance spectrometry, fourier transform infrared spectroscopy, thin layer chromatography, column chromatography, size exclusion chromatography, non-aqueous titrations, differential scanning calorimetry and thermogravimetrical analysis. / Chemistry / M. Sc. (Chemistry)

The synthesis of dipyridyl functionalized polysulfones with improved hydrophilicity, enhanced membrane morphology and excellent ATRP polymeric ligand properties was conducted by the following method: (a) the formation of lithiated polysulfone from unmodified polysulfone and the subsequent reaction with 2,2'-vinylidenedipyridine in tetrahydrofuran at -78 oC under argon atmosphere to afford the corresponding dipyridyl functionalized polysulfone. The stoichiometry of the reaction affects the degree of functionalization of the product. When equimolar amounts of 2,2'-vinylidenedipyridine are added to the lithiated polysulfone, the degree of functionalization obtained was 45%. However, the addition of 10% and 20% molar excess of 2,2'-vinylidenedipyridine to the corresponding lithiated polysulfone produced dipyridyl functionalized polysulfones with degrees of functionalization of 80% and 95%, respectively; and (b) the membranes obtained from unmodified polysulfone as well as dipyridyl functionalized polysulfones were characterized by atomic force microscopy, scanning electron microscopy, pure water permeation measurements and contact angle measurements. Amine chain end functionalized polystyrene and poly(methyl methacrylate) were prepared by Atom Transfer Radical Polymerization (ATRP) methods as follows: (a) •-Aminophenyl functionalized polystyrene was prepared in quantitative yields by ATRP methods using a new primary amine functionalized initiator adduct, formed in situ by the reaction of 1-(4-aminophenyl)-1-phenylethylene and (1-bromoethyl)benzene in the presence of copper (I) bromide/2,2'-bipyridyl as catalyst in diethyl ether at 110 oC, for the polymerization of styrene.(b) New •-bis(aminophenyl) and •,ω-tetrakis(aminophenyl) functionalized polymers were prepared in quantitative yields by the ATRP method using the following synthetic strategy: (i) the initiation of styrene polymerization with a new primary diamine functionalized initiator adduct, generated in situ by the reaction of stoichiometric amounts of 1,1-bis(4-aminophenyl)ethylene with (1-bromoethyl)benzene in the presence of copper (I) bromide/2,2'-bipyridyl as catalyst, afforded •-bis(aminophenyl) functionalized polystyrene; and (ii) •-bis(aminophenyl) functionalized poly(methyl methacrylate) was prepared by the ATRP method using the primary diamine functionalized initiator adduct as initiator for methyl methacrylate polymerization; and (iii) well defined •,ω-tetrakis(aminophenyl) functionalized polystyrene was prepared by the post ATRP chain end modification reaction of •-bis(aminophenyl) functionalized polystyrene with 1,1-bis(4-aminophenyl)-ethylene at the completion of the polymerization reaction. (c) Similarly, •-bis(4-dimethylaminophenyl) functionalized polystyrene was prepared by using a new tertiary diamine functionalized initiator adduct, formed in situ by treatment of equimolar amounts of 1,1-bis[(4-dimethylamino)phenyl]-ethylene with (1-bromoethyl)benzene in the presence of copper (I) bromide/2,2'-bipyridyl as the catalyst in diphenyl ether at 110 oC for the initiation of styrene polymerization by the ATRP method. Furthermore, the ATRP of methyl methacrylate, initiated by the new tertiary diamine functionalized initiator adduct, produced •-bis(4-dimethylaminophenyl) functionalized poly(methyl methacrylate). In addition, •,ω-tetrakis(4-dimethylaminophenyl) functionalized polystyrene was synthesized via a post ATRP chain end modification reaction of •-bis(4-dimethylaminophenyl) functionalized polystyrene with equimolar amounts of 1,1-bis[(4-dimethylamino)phenyl]ethylene at the completion of the polymerization process. vi Quantitative yields of the different amine functionalized polymers with predictable number average molecular weights (Mn = 1.3 x 103 – 16.4 x103 g/mol), narrow molecular weight distributions (Mw/Mn = 1.03 – 1.29) and controlled chain end functionality were obtained. Polymerization kinetics data was employed to determine the controlled/living character of each ATRP reaction leading to the formation of the different amine chain end functionalized polymers. The polymerization processes were monitored by gas chromatographic analyses. Polymerization kinetics measurements for all reactions show that the polymerizations follow first order rate kinetics with respect to monomer consumption. The number average molecular weight of the amine functionalized polymers increases linearly with percentage monomer conversion and polymers with narrow molecular weight distribution were obtained. The ATRP of styrene, catalyzed by a novel dipyridyl functionalized polysulfone/CuBr supported catalyst system, afforded well defined polystyrene with predictable number average molecular weight and narrow molecular weight distribution in a controlled/living free radical polymerization process. The substituted 1,1-diphenylethylene initiator precursor derivatives and the functionalized polymers were characterized by nuclear magnetic resonance spectrometry, fourier transform infrared spectroscopy, thin layer chromatography, column chromatography, size exclusion chromatography, non-aqueous titrations, differential scanning calorimetry and thermogravimetrical analysis. / Chemistry / M. Sc. (Chemistry)

Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal.

Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal

Block copolymers can self-assemble into a variety of periodic nanostructures and therefore, are promising candidates for a diverse range of applications. While self-assembly of block copolymers has been widely studied and exploited, graft copolymers have remained far less explored in this context. One of the primary reasons for this is that the most commonly used methods to prepare graft copolymers leads to polymers that do not have precisely defined structures; specifically, controlling the precise location of the grafted segments is a synthetically difficult challenge. In typical chain polymerization processes, statistically random incorporation of monomers takes place and consequently, the periodicity of the grafted segment along the backbone is very difficult to control precisely; therefore, such methods cannot be utilized to prepare periodically grafted copolymers. Some recent efforts towards the preparation of sequence regulated copolymers using controlled radical polymerization in conjunction with periodic dosing of a commoner could provide an alternative to better regulate the periodicity, although this will also not be perfectly periodic. The only approach to control the periodicity perfectly is to utilize condensation polymerization approaches, wherein one of the monomers serve as a spacer whereas the other provides the opportunity to install the graft segment, as depicted in Scheme 1. One of the earliest examples of the utilization of a condensation approach to locate desired units at periodic intervals was reported by Wagener and co-workers using Acrylic Diene Metathesis (ADMET) process.1 ]n periodicity ]n graft segment Scheme 1. Synthetic scheme for the preparation of periodically grafted copolymers using condensation polymerization. From our lab, Roy et al. developed periodically grafted amphiphilic copolymers (PGAC), based on a readily available starting material, diethyl malonate;2 melt trans-esterification between diethyl malonate, containing a pendant hexaethylene glycol monomethyl ether (HEG) segment and 1,22-docosane diol resulted in PGAC wherein the hydrophilic oligo ethylene glycol units were placed on every 27th atom along the backbone (Scheme 2). Such PGAC underwent self-segregation and adopted a folded zigzag conformation, which was driven by the intrinsic immiscibility of the alkylene and HEG segments and was reinforced by the strong tendency for long chain alkylene segments to crystallize in a paraffinic lattice. However, one of the drawbacks of the above approach was that the hydrophilic pendant unit was installed at the monomer stage and consequently, the synthetic approach does not allow easy variation of the hydrophilic grafted segment; this limits the flexibility and any structural variation of the pendant segment would be synthetically tedious. 150 oC DBTDL 5 20 DBTDL = Dibutyltin dilaurate Scheme 2. Synthesis of PGAC, based on diethyl malonate, and immiscibility-driven folding of such PGACs. Mandal et al. developed a more general strategy for the synthesis of such periodically grafted systems; they prepared periodically clickable polyesters carrying propargyl groups at regular intervals, by the solution polycondensation of 2-propargyl-1,3-propanediol or 2,2-dipropargyl-1,3-propanediol and the acid chloride of 1,20-eicosanedioic acid. Such periodically clickable polyesters were shown to react quantitatively with a fluoroalkyl azide3 and PEG 350 azide4, thus allowing them to place different kinds of functionalities precisely along the backbone, as shown in Scheme 3. The immiscibility of the alkylene and fluoroalkyl/PEG segments caused the polymer chains to fold in a zigzag fashion, thereby facilitating the segregation of these segments, as observed earlier in the study by Roy et al.2 The objective of this study was to place various desired functionalities along the polymer backbone and examine their effect on the self-assembly behaviour and morphology of such periodically clicked systems. Scheme 3. Synthetic scheme for the generation of periodically clickable polyesters and their subsequent functionalization via Cu-catalysed click chemistry. In Chapter 2, we describe an alternative general strategy for the scalable synthesis of periodically graftable polyesters and their subsequent functionalization to generate a wide variety of periodically grafted systems. The importance of our approach lies in our choice of the monomer, which is based on itaconic acid, an inexpensive and bio-sourced molecule. We demonstrated that dibutyl itaconate can be melt-condensed with aliphatic diols to generate unsaturated polyesters (Scheme 4); importantly, we showed that the double bonds in the itaconate moiety remain unaffected during the melt polymerization. A particularly useful attribute of these polyesters is that the exo-chain double bonds are conjugated to the ester carbonyl and therefore, can serve as excellent Michael acceptors. A variety of organic thiols, such as alkane thiols, MPEG thiol, thioglycerol, derivative cysteine etc., were shown to quantitatively Michael-add to the exo-chain double bonds and generate interesting functionalized polyesters; similarly, organic amines, such as N-methylbenzylamine, diallyl amine and proline also underwent Michael addition across the double bond (Scheme 4). Thus, such poly(alkylene itaconate)s could be utilized to place diverse functionalities at regular intervals along the polymer backbone. Scheme 4. Preparation of periodically graftable polyesters, based on itaconic acid, and their subsequent modification by Michael addition. In Chapter 3, we examined a series of periodically grafted polyesters carrying long crystallizable alkylene (C-20) segments along the backbone and pendant polyethylene glycol monomethyl ether (MPEG) segments grafted at periodic intervals. Such periodically grafted amphiphilic copolymers (PGAC) having MPEG graft segments of varying lengths were prepared by utilizing the activated exo-chain double bonds in poly(icosyl itaconate) (PII) that carries a 20-carbon alkylene segment; MPEG thiols of varying lengths (TREG, 350, 550 and 750) were quantitatively grafted under standard Michael addition conditions to yield the required graft copolymers, as shown in Scheme 5. Scheme 5. Synthesis of a series of periodically grafted amphiphilic copolymers (PGAC) utilizing post-polymerization modification via Michael addition with MPEG thiols of varying lengths. The immiscibility of the backbone alkylene and pendant MPEG segments, and the strong propensity of the alkylene segments to crystallize in a paraffinic lattice, drive these systems to fold in a zigzag fashion and subsequently organize into a lamellar morphology, as shown in Scheme 6. Interestingly, all the graft copolymers exhibited a clear and invariant melting transition at ~44°C that suggested the crystallization of the backbone C-20 segment; the MPEG segments were, however, amorphous except in the case of polymers carrying MPEG 550/MPEG-750 segments, wherein a second melting transition corresponding to the independent crystallization of the PEG segment was also seen. SAXS studies indicated that all of the samples exhibited lamellar morphologies wherein more importantly, the inter-lamellar spacing was seen to increase linearly with the MPEG length (Scheme 6). This study provides a new design for controlling the dimensions of the microphase-separated nanostructures at significantly smaller length scales (sub-10 nm) than is typically possible using block copolymers. Scheme 6. Schematic representation of formation of lamellar morphology in PGACs and control of interlamellar spacing in such systems. In order to understand the influence of having a mixture of MPEG lengths on the self-assembled morphology, in Chapter 4 we prepared a series of PGACs by co-grafting the parent poly(icosyl itaconate) with a mixture of two different MPEG thiols, namely MPEG-350 and MPEG-750; the mole-ratios of these two PEGs were varied to generate co-grafted PGACs, carrying different amounts of the two MPEG segments randomly distributed along the chain (Scheme 7). Parallely, we also examined the behaviour of physical mixtures of two different PGACs, one bearing MPEG-350 and the other MPEG-750 grafts; keeping the total MPEG content constant, we sought to examine the differences in the behaviour of randomly co-grafted polymers and physical mixtures. Scheme 7. Preparation of co-grafted PGACs and physical mixtures of two different PGACs. The co-grafted PGACs also exhibited a lamellar morphology; interestingly, the inter- lamellar spacing increased linearly with the total volume of PEG domain. This suggested that despite the presence of MPEG segments of two different lengths in the co-grafted samples, there occurred a reorganization of the PEG chains within the amorphous domain ensuring that the condition of incompressibility is not violated, thereby giving rise to a weighted average interlamellar spacing, as shown in Scheme 8. In contrast, the SAXS patterns of the physical mixtures revealed the presence of two distinct lamellar domains in the sample; this indicated that the two homo-grafted samples do not mix and form separate lamellar domains. The self- segregation induced folding and subsequent crystallization of the central alkylene segments clearly appeared to dominate the final morphology. Scheme 8. Schematic depiction of the possible scenarios that could arise when MPEG segments of two different lengths, namely MPEG350 and MPEG750, are present in the PGACs; top panel depicts the co-grafted PGACs, whereas the bottom panel shows the case of mixtures of PGACs with two different MPEG lengths. In Chapter 5, we have dealt with the design and synthesis of chain-end functionalizable polyalkylene itaconates. Changing the monomer from dibutyl itaconate to dipropargyl itaconate and using it in controlled excess allowed us to generate chain-end functionalizable polymers containing propargyl groups at the chain ends, in addition to the exo-chain double bonds along the backbone, thereby providing the opportunity for orthogonal functionalization. In order to obtain three different telechelic polymers with target DPs (degree of polymerization) of 5, 10 and 20 respectively, 3 different mole ratios of the two monomers (dipropargyl itaconate and 1,20-eicosanediol) were used (Scheme 9). Scheme 9. Synthetic scheme for the generation of chain-end functionalizable polyalkylene itaconates. Orthogonal functionalization of the resultant polymers was carried out using thiol-Michael addition and Cu(I)-catalysed alkyne-azide cycloaddition (AAC), without interference between the functional handles present along the polymer backbone and the chain-end, respectively. Michael addition with triethylene glycol thiol and subsequent Cu-catalysed click reaction with MPEG 750 azide led to the generation of ABA type triblock copolymers where the middle block is a periodically grafted amphiphilic block and the two linear end blocks are hydrophilic in nature. Furthermore, such propargyl-terminated polyalkylene itaconates were used as macromonomers to prepare multiblock copolymers. The telechelic polymers were first treated with PEG 600 diazide, resulting in the formation of alternating multiblock copolymers; these multiblock copolymers were further reacted with thioglycerol to generate amphiphilic multiblock copolymers where one of the blocks is a periodically functionalized amphiphilc block, as depicted in Scheme 10. In both these amphiphilic block copolymer systems, a key feature is that the periodically functionalized amphiphilic block folds into a zigzag form, as evident from the presence of a nearly invariant melting peak corresponding to the crystallization of the alkylene segment. Scheme 10. Preparation of multiblock copolymers utilizing propargyl-terminated polyalkylene itaconates as a macromonomer. In summary, the thesis has demonstrated the design and synthesis of a series of novel amphiphilic copolymers using a bio-sourced monomer, wherein the driving theme is the immiscibility driven self-segregation that leads to the folding of the chain; these have been thoroughly examined using DSC, SAXS, WAXS, variable temperature FT-IR and AFM measurements. References (1) Berda, E. B.; Lande, R. E.; Wagener, K. B. Macromolecules 2007, 40, 8547. (2) Roy, R. K.; Gowd, E. B.; Ramakrishnan, S. Macromolecules 2012, 45, 3063. (3) Mandal, J.; Krishna Prasad, S.; Rao, D. S. S.; Ramakrishnan, S. Journal of the American Chemical Society 2014, 136, 2538. (4) Mandal, J.; Ramakrishnan, S. Langmuir 2015, 31, 6035.

This dissertation reports the synthesis and characterization of semi-fluorinated polymers derived from the polymerization of bisphenols with fluoroalkenes. A series of diverse bisphenols were chosen from popular commercial bisphenols and new polycyclic aromatic hydrocarbon (PAH) derived bisphenols requiring synthesis. Step-growth condensation polymerization of bisphenols with three different fluoroalkene types was performed while probing polymerization conditions and the structure/properties relationship of the resulting fluoropolymers. The fluoroalkene monomers were chosen from bis(trifluorovinyloxy)biphenyl (TFVE), perfluorocyclohexene (PFCH), and perfluoro acyclic monomers, namely, perfluoro(4-methyl-2-pentene) and 1-perfluoroheptene to undergo this chemistry. This work is divided into four parts based on the polymerization methodology. The first section focuses on the development of a new class of fluorinated arylene vinylene ether (FAVE) and their chain extended polymers prepared via base-catalyzed step-growth polymerization of PAH bisphenols with the TFVE monomer. These reactions afforded polymers containing controlled terminal and enchained fluoroalkenylenes for latent reactivity such as post polymerization functionalization, chain extension, and/or crosslinking. In general, these PAH cores resulted in polymers with improved thermal properties The second portion describes the investigation of step-growth addition/elimination polymerizations of PAH bisphenols and PFCH to prepare a new class of fluoropolymers containing alternating rigid PAH linkages and enchained PFCH vinylene ether moieties in the backbone. The third section covers the preparation and characterization of semi-fluorinated poly(aryl ether sulfone)s by nucleophilic addition/elimination reactions of PFCH with sulfone bisphenols. From commercially bisphenols combined with PAH bisphenols, we introduced the industrially valuable and property enhancing diaryl sulfone unit in a series of semi-fluorinated copolymers. This modular approach greatly expands access to partially fluorinated aryl ether sulfone polymers intended for high performance applications in optoelectronics, separation/purification membranes, and composites. Finally, in the fourth section, a new class of semifluorinated polymers was synthesized via nucleophilic addition/elimination reactions of acyclic perfluoroalkenes with bisphenols. In particular, environmental concerns for biopersistent and highly regulated perfluorooctanoic acid (PFOA) is the driver for using perfluoroheptene, which is derived cleanly by the decarboxylation of these pollutants in one step. This provided a new class of semi-fluorinated materials with promising properties including thermal stable, processability, and transparent film formation.