The polymerization of norbornene in the presence of different bis(salicylaldiminate)copper(II) complexes and methylalumoxane has been investigated. In all cases a high molecular weight vinyl-type polymer was obtained. The presence of electron-withdrawing nitro groups on the chelate ligand markedly increased the activity of the catalyst. The influence on the catalytic performances and polymer characteristics as a function of reaction parameters, such as temperature, duration, and content of free trimethyl aluminum in the commercial MAO, was studied

Cotton fibers were modified by surface-initiated atom transfer radical polymerization of ethyl acrylate (EA) followed by copolymerization with styrene. Either ethyl 2-bromopropionate as a sacrificial free initiator or Cu(II) as a deactivator was used to optimize the EA grafting yield and to preserve the livingness of the chain ends for the subsequent growth of a poly(styrene) (PSty) block from the poly(ethyl acrylate) (PEA) grafts. The polymer-encapsulated cotton fibers were analyzed by Fourier transform infrared spectroscopy, scanning electron microscopy, differential scanning calorimetry (DSC), thermogravimetric analysis, and solid-state NMR (high-resolution 13C cross-polarization magic angle spinning, 1H spin-lattice relaxation times, and 1H free induction decay analysis NMR). The latter allowed the detection of the dynamic modifications associated with the presence of homo- and block copolymer grafts. In particular, the results of the DSC and NMR investigations suggest a heterogeneous morphology of the g-PEA-b-PSty grafted skin, which could be described as an inner layer of g-PEA sandwiched between the semicrystalline cellulose of the core fiber and the high glass transition temperature PSty of the covalently linked outer layer. Such morphology results in a reduced molecular mobility of the PEA chains.

Summary: Continuous cold Ar plasmas were used to activate the mercerised cotton fabric towards surface‐initiated graft polymerisation of glycidyl methacrylate, 2‐hydroxyethyl methacrylate (HEMA) and 1,1,2,2‐tetrahydroperfluorodecyl methacrylate (XFDMA). Single and multi‐step processes, carried out either in the plasma chamber (one‐step and two‐step processes) or ex situ after plasma treatment, were explored to optimise the grafting efficiency. The mechanical properties of the grafted cotton were substantially unaffected. Grafting with XFDMA gave good results only when the plasma activation was performed on monomer‐impregnated fabrics, as shown by gravimetry, ATR FT‐IR spectroscopy, and water and oil repellence tests. On the contrary, with HEMA better results were obtained by in situ grafting from monomer vapours.Mercerized cotton fabric before (left) and after (right) graft polymerisation of the fluorinated methacrylate XFDMA from the plasma‐activated surface.magnified imageMercerized cotton fabric before (left) and after (right) graft polymerisation of the fluorinated methacrylate XFDMA from the plasma‐activated surface.