Polymerization corona

The compounds which gave the heaviest coatings after heating (taking into account the amount of monomer volatilized), included triallyl-amine, acrylonitrile, toluene, and styrene. As the list in Table I shows it is not necessary for the monomer to be a vinyl compound in the strict sense of the word for a non-volatile polymer product to form in corona discharge. Toluene, benzene, benzotrifluoride, and even acetone gave measurable yields. There seemed to be no pattern of relationship between the structure of a monomer and its yield in corona polymerization. 

Table II. Effect of Halogenated Additives on Corona Polymerization of Styrene Yield of Polymer as a Percent of Styrene Used...

In considering chemical explanations for corona polymerization, both free radical and ionic intermediates are possibilities. Experiments were run with various additives to styrene that might be expected to inhibit each kind of reaction through combination with the active intermediate but no clear-cut reduction in yield was observed. Benzoquinone at 1 and 2 mole % gave normal yields. Water and butylamine were extensively... 

Sasidharan, M. and Nakashima, K. (2013) Core shell corona polymeric micelles as a versatile template for synthesis of inorganic hollow nanospheres. Acc. Chem. Res., 47 (1), 157 167. 

Other Polymerization Methods. Although none has achieved commercial success, there are a number of experimental alternatives to clay-catalyzed or thermal oligomeriza tion of dimer acids. These iaclude the use of peroxides (69), hydrogen fluoride (70), a sulfonic acid ion-exchange resia (71), and corona discharge (72) (see Initiators). 

While polymeric surfaces with relatively high surface energies (e.g. polyimides, ABS, polycarbonate, polyamides) can be adhered to readily without surface treatment, low surface energy polymers such as olefins, silicones, and fluoropolymers require surface treatments to increase the surface energy. Various oxidation techniques (such as flame, corona, plasma treatment, or chromic acid etching) allow strong bonds to be obtained to such polymers. 

Wang X, Akagi T, Akashi M et al (2007) Development of core-corona type polymeric nanoparticles as an anti-HIV-1 vaccine. Mini-Rev Org Chem 4 281-290... 

In previous sections, much emphasis has been put on block copolymer micelles with a spherical morphology. It was shown in Sect. 5 that the characteristic sizes of both the spherical core and corona of block copolymer micelles can be precisely adjusted by essentially controlling the chemical nature and the degree of polymerization of the constituent blocks. For several applications of block copolymers micelles including, e.g., micellar templating... 

Other Polymerization Methods. Experimental allemalives include the use of peroxides, hydrogen fluoride, a sulfonic acid ion-exchange resin, and corona discharge. 

The aggregation numbers Nagg is determined as 27 for C1-(EO)53-C4-VB and 38 for Cr(EO)53-C7-VB micelles by analysis of fluorescence curves. A micelle formation mechanism is proposed for nonionic polymeric surfactants with weakly hydrophobic groups. At low concentrations of PEO macromonomers, large loosely aggregated structures involving the PEO chains are formed. At higher concentrations normal micelles form. These are star-shaped, with a hydrophobic core surrounded by a corona of PEO chains. 

Block or graft copolymers in a selective solvent can form structures due to their amphiphilic nature. Above the critical micelle concentration (CMC), the free energy of the system is lower if the block copolymers associate into micelles rather than remain dispersed as single chains. Often the micelles are spherical, with a compact core of insoluble polymer chains surrounded by a corona of soluble chains (blocks) [56]. Addition of a solvent compatible with the insoluble blocks (chains) and immiscible with the continuous phase leads to the formation of swollen micelles or polymeric micro emulsion. The presence of insoluble polymer can be responsible for anomalous micelles. 

Tg = 125-140°C, and was stable in a N2 atmosphere to 220°C. The 13C NMR spectrum revealed the presence of 7t-interaction between those chromophoric groups that are in isotactic relationship to each other ( 30-35% of total). The orientation of the chromophores in a PPNA sample (Tg = 125°C) was achieved in a thin film by the corona poling technique at temperatures above Tg. The subsequent freezing process resulted in a polymeric film that exhibited an initial high second-order nonlinear coefficient, d33=31 pm/V, as measured by Maker-fringe technique with 1.06 im fundamental. 

Following the corona-discharge treatment of a silicone surface and the subsequent graft polymerization of AAc, type I atelocollagen was immobilized onto the grafted surface with the use of water-soluble carbodiimide [176, 177]. As depicted in Fig. 17, the immobilization reaction involves two steps, i.e., activation of carboxylic acids and the following nucleophilic substitution with prima-... 

---