Porogenic agent

Additionally, TADDOL derivative (9) which contained an additional styrene group was first prepared in solution and then underwent bulk polymerization in the presence of various porogenic agents in order to obtain soHd-phase-bound catalyst (10) with the desired porosity (Scheme 4.5) [67]. 

The inner porous morphology of these resins is distinguished by interconnected channels that form a porous network, which pervades the rigid, significantly cross-linked polymer matrix [205], These materials are often synthesized by suspension polymerization [206], where a polymerization mixture which includes a cross-linking monomer, a functional comonomer or comonomer, an initiator, and a porogenic agent is polymerized. 

In a slightly modified approach, the MIPs can be rendered super-porous by the use of 1-25% iso-octane as a porogenic agent [40,41]. The porogen is composed of a mixture of solvents in which the porogenic agent (iso-octane) acts as a bad solvent for the growing polymer chains, while the other solvent (toluene for... 

Microporous beads are weakly crosslinked resins obtained by suspension polymerisation of styrene and divinylbenzene in the absence of any porogen agent. This process leads to the formation of a homogeneous network evidenced by a glassy and transparent appearance. The most commonly used supports for solid-phase organic synthesis and catalysis are styrene-divinylbenzene copolymers crosslinked with only 1-2% DVB. Many of their derivatives are commercially available [20]. 

In most of the cases, this reaction seems to be very sensitive to the polymer morphology controlled by crosslinking and the nature of the porogen agent which determine the performance of the immobilized catalyst. 

When some porogenic agent such as ZnCl2, layered clay, or cross-linking diethylbenzene is added to the precursors to increase the number of pores in the amorphous carbon, the number of micropores also increases leading to an increase in reversible capacity. This cannot be explained with the other mechanism. 

Originally, the Bellcore Company adopted a tedious method to prepare polymer electrolyte membranes. The main disadvantage of the method is that the plasticizer added as porogenic agent is very difficult to remove, producing serious adverse effects on the quality of the SEI film and electrochemical performance of the prepared lithium-ion batteries. Its industrial application was never realized in production. 

Porous ST-DVB copolymers are obtained by suspension copolymerization of styrene with divinylbenzene. Their porous structure is determined by the amount of the DVB crosslinking agent, the type of porogenic agent and its concentration in admixture with polymerizable monomers (refs. 7-12). A number of different methods was used to investigate the porous structure of some modified polymers (Table 2, samples 5-7). 

The dependence of the structure of polymers containing EDA and DETA groups on the size of the molecule of hydrocarbon (inert solvent, porogenic agent) was also investigated. The largest pores contain polymers obtained with the n-decane solvent (refs.9,11). 

Thus, the investigation of the porous structure of polymeric sorbents and the determination of dependencies of the porous structure parameters on the synthesis condition (the eunount and the nature of the crosslinking agent, the amoxint and the nature of the porogenic agent and the molecular mass of polystyrene) make it possible to synthesize the porous polymers of certain structure. The established laws of the adsorption of acid gases by modified polymers of different structure make it possible to optimize their porosity at which the maximum accessibility of functional groups for the adsorbed molecules is attained. 

---