Porogenic additives

Shaping additives may act as lubricants, plasticizers, cements, porosity promoters (porogenic additives), etc. [9]. The powdered starting material mixed with the additives may be dry, or converted to a plastic pulp by the addition of a suitable liquid. One sometimes distinguishes ... 

Nam YS, Yoon JJ, Park TG. A novel fabrication method of macroporous biodegradable polymer scaffolds using gas foaming salt as a porogen additive. J Biomed Mater Res 2000 53. 

Lin HR, Kuo CJ, Yang CY, Shaw SY, Wu YJ. Preparation of macroporous biodegradable PLGA scaffolds for cell attachment with the use of mixed salts as porogen additives. J Biomed Mater Res 2002 63 271-9. 

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 fact that adding a better solvent to the mixture results in a shift of the distribution to smaller pore sizes has been explained by the mechanism of pore formation, postulated for macroporous resins in the late 1960s [101-103]. The addition of a poor solvent causes the phase separation to occur early, whereas the precipitated polymer nuclei are swollen with monomers, which present a better solvating agent than the porogen. Due to the high monomer concentration within the globuli. 

In the noncovalent approach, the monomer is self-assembled around the tern-plating molecule and then again copolymerized with the additional monomer. The template is then removed by using a porogenic solvent. 

An additional porous polymer is poly(glycidyl methacrylate-ethyleneglycol dimethacrylate) (see Figure 2.46) that is synthesized by suspension polymerization in the presence of an inert porogen in the polymerization reaction, obtaining a material with an internal macroporous morphology characterized by an interconnected pore network, which permeates the extensively cross-linked polymer matrix [209],... 

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