Block copolymers Multicomponent polymer

Fayt, R. Jerome, R. Teyssie, P. Molecular Design of Multicomponent Polymer Systems. XIV. Control of the Mechanical Properties of Polyethylene-Polystyrene Blends by Block Copolymers. J. Polym. Sci., Part B Polym. Phys. 1989, 27, 775. 

Fayt R, Jerome R, Teyssie Ph. Molecular design of multicomponent polymer systems. XIV. Control of the mechanical properties of PE/PS blends by block copolymers. J Polym Sci Polym Phys Ed 1989 27 775-793. 

The concept for the design of supramolecular liquid crystals and supramolecular polymers has opened new fields in materials and polymer science, which are ever expanding. New stable and dynamic structures are generated by self-organization of these materials. Related functional polymeric materials such as dendrimers [140-143], block copolymers [144], polymer blends [145,146], rotaxanes [147-149], anisotropic gels [150-152], metallo-supramolecular polymers [153,154], nanoobjects [155,156] as well as supramolecular polymers are also obtained by self-assembly of multicomponents through noncovalent interactions. 

As more complex multicomponent blends are being developed for commercial appHcations, new approaches are needed for morphology characterization. Often, the use of RuO staining is effective, as it is sensitive to small variations in the chemical composition of the component polymers. For instance PS, PC, and styrene—ethylene/butylene—styrene block copolymers (SEES) are readily stained, SAN is stained to a lesser degree, and PET and nylons are not stained (158,225—228). 

Surfactants used as lubricants are added to polymer resins to improve the flow characteristics of the plastic during processing they also stabilise the cells of polyurethane foams during the foaming process. Surfactants are either nonionic (e.g. fatty amides and alcohols), cationic, anionic (dominating class e.g. alkylbenzene sulfonates), zwitterionic, hetero-element or polymeric (e.g. EO-PO block copolymers). Fluorinated anionic surfactants or super surfactants enable a variety of surfaces normally regarded as difficult to wet. These include PE and PP any product required to wet the surface of these polymers will benefit from inclusion of fluorosurfactants. Surfactants are frequently multicomponent formulations, based on petro- or oleochemicals. 

We consider an incompressible (m-l-1) multicomponent mixture of polymers consisting of m different types of polymer chains within a matrix referred to as 0 . Components may be either homopolymers of a given chemical species or, e.g. homopolymer sections in block copolymers. Hydrogenated and deuterated species of the same homopolymer are considered as different components. In this context a diblock copolymer is a two-component polymer system. A mixture of partially protonated diblock chains hA-dB with deuterated diblock chains is consequently regarded as a four-component system. 

Among other approaches, a theory for intermolecular interactions in dilute block copolymer solutions was presented by Kimura and Kurata (1981). They considered the association of diblock and triblock copolymers in solvents of varying quality. The second and third virial coefficients were determined using a mean field potential based on the segmental distribution function for a polymer chain in solution. A model for micellization of block copolymers in solution, based on the thermodynamics of associating multicomponent mixtures, was presented by Gao and Eisenberg (1993). The polydispersity of the block copolymer and its influence on micellization was a particular focus of this work. For block copolymers below the cmc, a collapsed spherical conformation was assumed. Interactions of the collapsed spheres were then described by the Hamaker equation, with an interaction energy proportional to the radius of the spheres. 

Miyaki and Fujimoto and co-workers [16,17] have obtained an even finer distribution of fixed charge groups by casting films from multicomponent block copolymers such as poly(isoprene- >-styrene- >-butadiene- >-(4-vinyl benzyl)dime-thylamine- Msoprene). These films show a very regular domain structure with a 200-500 A spacing. After casting the polymer film, the (4-vinyl benzyl) dimethy-lamine blocks were quatemarized with methyl iodide vapor, and the styrene blocks were sulfonated with chlorosulfuric acid. 

Benoit et al. [11-12] and Akcasu et al. [13-15] have extended de Gennes formula to describe multicomponent polymer systems. Their results are reproduced in Appendix A in a matrix form (following Akcasu [13-15]). Consider a number of components (noted A, B, etc.) with degrees of polymerization NA, etc., volume fractions A, etc., monomer volumes vA, etc. Some of these components could be block copolymers. Having one of the components (called matrix component) as a homopolymer simplifies the calculations. The main result is ... 

Multicomponent polymers systems such as polyblends, and block copolymers often exhibit phase separation in the solid state which results in one polymer component dispersed in a continuous phase of a second component. The morphological properties of these systems depend upon a number of factors such as the molar ratios of the components, the molecular weights, the thermal history of the system and, for solvent cast films, the solvent and drying conditions. 

Multicomponent polymeric materials with microheterogeneous mophologies include a number of polymer blends and block copolymers, however, an especially easy way to bring about the desired morphology is through interpenetrating polymer networks. Several papers in the symposium are concerned with IPN s and related materials. 

Block copolymers are an example of multicomponent polymer systems for which the problem of separate investigation of each component (block) of the copolymer is of particular interest. The PL method permits a successive separation of each block of the copolymer for the investigation of the IMM of the latter using luminescent markers . The PL method was applied to the study of the three-block copolymers of the ABA and BAB types where A and B are PMMA and polystyrene(PS)blocks. 

K. M. Hong and J. Noolandi (1981) Theory of inhomogeneous multicomponent polymer systems. Macromolecules 14, pp. 727-736 ibid., (1982) Interfacial properties of immiscible homopolymer blends in the presence of block copolymers. 15, pp. 482-492... 

Polymer-based multicomponent systems are abundant in many applications. The properties and performance of particulate-filled systems, such as elastomers and impact modified polymers, and also polymer blends, block copolymers, and fiber reinforced systems, depend to a large extent on the distribution of the components. Hence the local analysis of these distributions down to sub-100 nm length scales (dictated, e.g., by the size of primary filler particles) is of considerable significance. Materials contrast in several AFM approaches offers the possibility to address these issues directly at the surface of specimens or on bulk samples that have been prepared correspondingly. 

Multicomponent Polymer Systems, edited by I. S. Miles and S. Rostami, Longman Scientific and Technical, London, 1992. Three of the ten chapters of this book are devoted to blends, block copolymers and rubber-toughened polymers. 

Over the past twenty years or more there has been widespread interest in various kinds of multicomponent polymer systems, including polyblends, block copolymers, and segmented elastomers. 

After a decade of development and application, a number of original papers on continuous thermodynamics have appeared in the literature. Rtosch and Kehlen [28 30] reviewed the state-of-the-art on systems containing synthetic polymers [28, 29] and those containing petrol fractions and other multicomponent low molecular hydrocarbon systems [30]. Therefore, this overview focuses on systems containing copolymers characterized by multivariate distribution functions and those containing block copolymers. Of source, all important aspects regarding homopolymer systems are automatically included in our discussion. 

The behavior of multicomponent polymer systems has been the subject of several recent reviews. Bucknall has examined polymer blends and grafts, with particular reference to the toughening of plastics. All aspects of block copolymers have been explored by Noshay and McGrath. Manson and Sperling reviewed the entire field of polymer blends and composites. 

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