Cationically modified polymer

Topical spermicides such as nonoxynol-9 (N9) and benzalkonium chloride act on sperm membranes through a detergent effect, namely, hydrophobe-hydrophobe interaction between the active and substrate (spermatozoa). The idea was to optimize the cationic/hydrophobic polymer in the drug delivery system so epithelial cells were protected without sacrificing the drug s spermicidal activity. One of the questions that needed to be answered in designing an optimum cationic/hydrophobe modified polymer was the effect of the hydrophobe on the drug activity (N9 initially, and other actives subsequently). 

Any catalytic effects of these modified polymers must reflect, therefore, only the influence of their apolar domains and their cationic charges. 

Figure 1. Surface activity of unmodified (Polymer JR 400) and hydrophobe modified (Quatrlsoft LM 200) cationic celluloslc polymers as a function of polymer concentration.

Figure 2. Effect of ageing and compression of adsorbed layers of unmodified and hydrophobe modified cationic celluloslc polymers on their surface pressure. (Reprinted with permission from ref. 21. Copyright 1985 Allured Publishing.)...

Figure 3. The fluorescence characteristics of pyrene In solutions of hydrophobe modified and unmodified cationic celluloslc polymers both In the presence and absence of SDS.

Low charge density, hydrophobically modified polybetaines were shown to interact and comicellize with nonionic, anionic, cationic, and amphoteric surfactants [181-183] and many ionic organic dyes [264,265]. The association mechanism of hydrophobically modified polymers and surfactants in dependence on the concentration of interacting components can be modeled by two pathways (Scheme 21) [183]. 

M 15. — — — — Solvent-modified polymer networks. Part II. Effect of structure on cation-exchange kinetics in sulphonated styrene-divinyibenzene copolymers. J. Chem. Soc.T963, 2779. 

Several methods employing capillary wall modifications have been developed and they can be grouped into several categories dynamic coatings by the addition of a cationic modifier (usually an amine) to the BGE [47,48], permanent coatings by physical adsorption of a cationic modifier (usually a polymer) [47,48], and permanent coating by covalent bonding of a hydrophilic polymeric layer [49]. 

Q. Wen, L. Liu, Q. Yang, F. Lv, S. Wang, Dopamine-Modified Cationic Conjugated Polymer as a New Platform for pH Sensing and Autophagy Imaging. Adv. Fund. Mater. 2013,23,764-769. 

This test method involves a rapid quantitative determination of the residue in bitumen emulsion using a moisture analyser. It is applicable to all non-solvent-containing emulsion types, anionic, cationic, non-polymer-modified or polymer-modified bitumen emulsions. 

Corn oil-based polymer resin, prepared by the cationic polymerisation of conjugated corn oil, styrene and divinylbenzene, using boron trifluoride diethyl etherate modifled by Norway fish oil as the initiator with 4-vinylbenzyl triethylammonium cation modified montmorillonite clay (VMMT) nanocomposites were reported. The resultant nanocomposites with 2-3 wt% VMMT exhibited significant around two-fold improvements in tensile modulus, tensile strength and toughness when compared to the pristine polymer. There is an improvement in thermal stability up to 400°C in the nanocomposites. ... 

Intercalating/silicate modifying polymer with exchangeable cations... 

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