PS-PMMA

The main experimental techniques used to study the failure processes at the scale of a chain have involved the use of deuterated polymers, particularly copolymers, at the interface and the measurement of the amounts of the deuterated copolymers at each of the fracture surfaces. The presence and quantity of the deuterated copolymer has typically been measured using forward recoil ion scattering (FRES) or secondary ion mass spectroscopy (SIMS). The technique was originally used in a study of the effects of placing polystyrene-polymethyl methacrylate (PS-PMMA) block copolymers of total molecular weight of 200,000 Da at an interface between polyphenylene ether (PPE or PPO) and PMMA copolymers [1]. The PS block is miscible in the PPE. The use of copolymers where just the PS block was deuterated and copolymers where just the PMMA block was deuterated showed that, when the interface was fractured, the copolymer molecules all broke close to their junction points The basic idea of this technique is shown in Fig, I. 

Fig. 6. Variation of interface toughne.ss with area den.sity of copolymer for a range of different molecular weight PS-PMMA copoly mens between PMMA and PPO (or PPE) [39J.

Fig. 7. Variation of Gc with E for both PS-PMMA diblocks between PPE and PMMA ( ) and PS-PVP diblocks between PS and PVP ( ) [13]. The solid line is a fit to Eq. 8 and the dashed line to Eq. 7.

Char, K., Brown, H.R. and Deline, V.R., Effects of a diblock copolymer on adhesion between immiscible polymers, 2. PS-PMMA copolymer between PPO and PMMA. Macromolecules, 26(16), 4164-4171 (1993). 

The soapless seeded emulsion copolymerization method was used for producing uniform microspheres prepared by the copolymerization of styrene with polar, functional monomers [115-117]. In this series, polysty-rene-polymethacrylic acid (PS/PMAAc), poly sty rene-polymethylmethacrylate-polymethacrylic acid (PS/ PMMA/PMAAc), polystyrene-polyhydroxyethylmeth-acrylate (PS/PHEMA), and polystyrene-polyacrylic acid (PS/PAAc) uniform copolymer microspheres were synthesized by applying a multistage soapless emulsion polymerization process. The composition and the average size of the uniform copolymer latices prepared by multistage soapless emulsion copolymerization are given in Table 11. 

The authors of [317] investigated compositions based on PS, PMMA and styrene-acrylonitrile copolymer grafted to various fillers and found that it was possible, in this manner, to obtain particles with a grafted polymeric coating of sufficiently homogeneous thickness. 

These thiohydroxamic esters have seen use in grafting of PAN onto PE,iM of PS, PAM and I MPAM onto cellulose127128 and of PS, PMMA, PVP and PAM onto poly(arylene ether sulfone).12 7 The process involves derivitization of a parent carboxy functional polymer to form the thiohydoxamic ester 82 (R=polvmcr) which then behaves as a polymeric transfer agent and/or radical generator. 

Minor (by amount) functionality is introduced into polymers as a consequence of the initiation, termination and chain transfer processes (Chapters 3, 5 and 6 respectively). These groups may either be at the chain ends (as a result of initiation, disproportionation, or chain transfer,) or they may be part of the backbone (as a consequence of termination by combination or the copolymerization of byproducts or impurities). In Section 8.2 wc consider three polymers (PS, PMMA and PVC) and discuss the types of defect structure that may be present, their origin and influence on polymer properties, and the prospects for controlling these properties through appropriate selection of polymerization conditions. 

With diblock copolymers, similar behavior is also observed. One component is enriched at the surface and depending on miscibility and composition a surface-induced ordered lamellar structure normal to the surface may be formed. Recent investigations include poly (urethanes) [111], poly(methoxy poly (ethyleneglycol) methacrylate)/PS [112] and PS/PMMA [113, 114]. In particular the last case has been extensively studied by various techniques including XPS, SIMS, NR and optical interferometry. PS is enriched at the surface depending on blockcopolymer composition and temperature. A well ordered lamellar structure normal to the surface is found under favourable conditions. Another example is shown in Fig. 6 where the enrichment of poly(paramethylstyrene), PMS(H), in a thin film of a di-... 

The alignment of a lamellar microstructure by electric fields has been reported [64], The electric fields were applied across a melt of a PS-PMMA block copolymer and were maintained throughout cooling down to below the glass transition point. SAXS studies show persuasive evidence that the microstructure was aligned by an electric field. 

The synthesis of the (PS)(PMMA)(PCL) 3//-ABC star has been achieved with the use of a triheterofunctional initiator (ROP, ATRP, NMP) as shown in Scheme 85 [160]. SEC characterization experiments of the different intermediates confirmed the successful synthetic procedure. 

Nonionic amphiphilic block copolymers in aqueous solution are typically formed of a water-soluble hydrophilic block, e.g., PEO, PMVE, PNIPAM, linked to a hydrophobic block, e.g., PPO, PBO, PS, PMMA. 

Crew-cut micelles were prepared from PS-PMMA-PAA triblock copolymers with a large PS block [270]. The morphology of these micelles was found to be dependent on the starting nonselective solvent (dioxane, THF, or DMF), as discussed previously in Sect. 6. 

Eight months after submission of the first manuscript describing successful preparation of nanolithography masks from PS-PMMA block copolymers,... 

Fig. 7 SEM images of nanoporous thin films from cylinder-forming PS-PMMA diblock copolymers. Reproduced from [25]... 

Fig. 9 Gold nanoparticles (left hand side of the image) prepared by deposition onto a nanoporous PS mask derived form a PS-PMMA block copolymer. Reproduced from refernence [33]... 

As demonstrated above, the use of PS-PMMA block copolymers as precursors to nanoporous materials is quite well established. Electric field alignment... 

Poly vinyl chloride v Graft(copolymer) PS/PMMA Poly (phenyl siloxane)... 

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