Hair is a proteinaceous fibre with a strongly hierarchical organization of subunits, from the alpha-keratin chains, via intermediate filaments, to the fibre. The chemistry of the different morphological compartments results in exciting physical properties, including the hydrophilic/hydrophobic paradox. The present tutorial review will be of interest for protein- as well as polymer chemists, who want to learn from nature, and also for biochemists interested in the cytoskeleton and particularly in intermediate filaments; it also presents a scientific basis for hair cosmetics.

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The true aim of biomaterials research is to create implant surfaces which interact actively with the biological system and provoke exactly the same reactions as the corporal tissues do. The improvement in the interface compatibility of polymers selected for implantation by directed surface modification is an important contribution to biomaterial development. Different polymer properties are adjusted and characterized independently of the carrier polymer by means of introduction of modern surface analytical methods and surface techniques. In addition, the interactions between the modified polymer surface and the biological system are measured. In this way, the hydrophilization of a polyurethane (Tecoflex™) and a poly(ether sulfone) by plasma induced graftcopolymerization of hydrogels like poly(hydroxyethyl methacrylate) leads to improved blood compatibility. Functionalization by means of SO 2 plasma treatment of medical grade poly(vinyl chloride) increases the adsorption of the basal membrane protein fibronectin, which correlates with an improvement in cell growth. A suitable interface for an improved cell growth of human vascular endothelial cells as well as for cornea endothelial cells has been created by immobilization of the cell adhesion mediator fibronectin using bifunctional spacer molecules at several carrier polymer surfaces like smooth poly(vinyl chloride), modified polyurethane, Tecoflex™ and poly(dimethyl siloxane).

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Communication: Phenoxycarbonyloxymethyl ethylene carbonate 4 was synthesized from glycerol carbonate and phenyl chloroformate. Polyurethanes with pendant hydroxyl groups were obtained from polycondensation reactions of this AA* monomer with diamines. These polymers contain primary as well as secondary hydroxyl groups. The obtained polyurethanes are amorphous materials. The glass transition temperature decreases with increasing number of methylene groups between the urethane groups.

SUMMARY:Poly(L-lactide)-block-poly(L-amino acids) block copolymers were prepared via polymerization of a-amino acid N-carboxyanhydrides with amino-terminated poly(L-1actide)s as macroinitiators. ?kro types of macroinitiators were used, one with an aminopropoxy head group (number-average molecular weight a, = 22000) and the other one with a phenylalanine end group (a,, = 18OOO). The first macroinitiator was obtained by polymerization of (L,L)-lactide with an initiator prepared in situ from diethylzinc Et,Zn and N-tert-butoxycarbony1-1-amino-3-propano1, followed by deprotection of the amino group. The second macroinitiator was obtained by endcapping of poly(L-lactide) with Ntert-butoxycarbonylphenyldanine and deprotection of the amino group. 'H-and 13C NMR spectroscopies confirm the block structure of the copolymers obtained. In differential scanning calorimetry curves only one melting transition characteristic of the poly(L-lactide) block is observed, on further heating decomposition occurs. By thermogravimetry two steps of decomposition are observed, the first one being assigned to the decomposition of the poly(L-lactide) block, and the second one to that of the poly(amino acid) block, by comparison with the thermal behaviour of the corresponding homopolymers.

Low-temperature plasma technologyboth glow discharge under reduced pressure as well as barrier discharge under normal pressureare well established in different industrial applications. Since recently, however, the plasma technology is being introduced in textile industry as well. Fields of application are desizing, functionalizing, and design of surface properties of textile fibers. Plasma technology is suitable to modify the chemical structure as well as the topography of the surface of the material. Examples of natural as well as man-made fibers prove the enormous potential of plasma treatment of textile materials. It has proven to be successful in shrink-resist treatment of wool with a simultaneously positive effect on the dyeing and printing. Not only the chemical structure of the surface is modified using different plasma gases but also the topography of the surface. A highly hydrophobic surface with a particular surface topography in contact with water is extremely dust- and dirt-repellent and hence should be also repellent to bacteria and fungi. Man-made fibers to be used under chemical stress are modified with diffusion-barrier layers on their surfaces without modifying the bulk properties; hence, the stability of those fibers is significantly improved.

Poly(allyl methacrylate) (PAMA) and random copolymers of styrene (St) with allyl methacrylate (AMA) were prepared via atom transfer radical polymerization. For the homopolymerization of AMA, the maximum conversion depends on the reaction conditions and on the monomer/initiator ratio. For the copolymerization, AMA conversions of up to 90% were obtained while no cross-linking occurred. Kinetic studies of the homopolymerization revealed a controlled polymerization up to a certain conversion whereas at higher conversions, multimodal molecular weight distributions caused by branching reactions and cross-linking were observed. The copolymerization of AMA with St allowed a controlled reaction up to conversions higher than 90%. The copolymers obtained were soluble in standard organic solvents. In a subsequent reaction, these copolymers were cross-linked both thermally and photochemically using suitable initiators. Moreover, pendant double bonds were brominated quantitatively.