Influence of Functional Group Concentration on Hypercrosslinking of Poly(vinylbenzyl chloride) PolyHIPEs: Upgrading Macroporosity with Nanoporosity

With the aim to study the influence of monomer ratio in poly(high internal phase emulsions) (polyHIPEs) on the polymer network architecture and morphology of poly(vinylbenzyl chloride-co-divinylbenzene-co-styrene) after hypercrosslinking via the internal Friedel–Crafts process, polyHIPEs with 80% overall porosity were prepared at three different initial crosslinking degrees, namely 2, 5, and 10 mol.%. All had typical interconnected cellular morphology, which was not affected by the hypercrosslinking process. Nitrogen adsorption and desorption experiments with BET and t-plot modelling were used for the evaluation of the newly introduced nanoporosity and in combination with elemental analysis for the evaluation of the extent of the hypercrosslinking. It was found that, for all three initial crosslinking degrees, the minimum amount of functional monomer, 4-vinylbenzyl chloride, was approximately 30 mol.%. Hypercrosslinking of polymers with lower concentrations of functional monomer did not result in induction of nanoporosity while the initial crosslinking degree had a much lower impact on the formation of nanoporosity.

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Porous scaffolds with the structure of an interpenetrating polymer network made by gelatin methacrylated nanoparticle-stabilized high internal phase emulsion polymerization targeted for tissue engineering

RSC Advances ◽

10.1039/d1ra03333f ◽

2021 ◽

Vol 11 (37) ◽

pp. 22544-22555

Author(s):

Atefeh Safaei-Yaraziz ◽

Shiva Akbari-Birgani ◽

Nasser Nikfarjam

Keyword(s):

Tissue Engineering ◽

Extracellular Matrix ◽

Cell Growth ◽

Polymer Network ◽

Synthetic Polymers ◽

Tissue Scaffolds ◽

Interpenetrating Polymer Network ◽

Porous Scaffolds ◽

Promising Strategy ◽

Internal Phase

The interlacing of biopolymers and synthetic polymers is a promising strategy to fabricate hydrogel-based tissue scaffolds to biomimic a natural extracellular matrix for cell growth.

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Smart Hydrogels for Pharmaceutical Applications

Materials Science and Engineering ◽

10.4018/978-1-5225-1798-6.ch044 ◽

2017 ◽

pp. 1133-1164

Author(s):

Snežana S. Ilić-Stojanović ◽

Ljubiša B. Nikolić ◽

Vesna D. Nikolić ◽

Slobodan D. Petrović

Keyword(s):

Electric Fields ◽

Polymer Network ◽

Three Dimensional ◽

Chemical Properties ◽

Stimuli Responsive ◽

Crosslinking Degree ◽

Color Transparency ◽

Hydrogel Network ◽

Physical And Chemical ◽

Responsive Hydrogels

The latest development in the field of smart hydrogels application as drugs carriers is shown in this chapter. Hydrogels are three-dimensional polymer network consisting of at least one hydrophilic monomer. They are insoluble in water, but in the excess presence of water or physiological fluids, swell to the equilibrium state. The amount of absorbed water depends on the chemical composition and the crosslinking degree of 3D hydrogel network and reaches over 1000% of the xerogel weight. Stimuli-responsive hydrogels exhibit significant change of their properties (swelling, color, transparency, conductivity, shape) due to small changes in the external environment conditions (pH, ionic strength, temperature, light wavelength, magnetic or electric fields, ultrasound, or a combination thereof). This smart hydrogels, with different physical and chemical properties, chemical structure and technology of obtaining, show great potential for application in the pharmaceutical industry. The application of smart hydrogels is very promising and at the beginning of the development and exploitation.

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Variation in Feedstock Wood Chemistry Strongly Influences Biochar Liming Potential

Soil Systems ◽

10.3390/soilsystems3020026 ◽

2019 ◽

Vol 3 (2) ◽

pp. 26 ◽

Cited By ~ 10

Author(s):

Sossina Gezahegn ◽

Mohini Sain ◽

Sean Thomas

Keyword(s):

Functional Group ◽

Pyrolysis Temperature ◽

Chemical Properties ◽

Base Cation ◽

Surface Functional Group ◽

Wood Chemistry ◽

Incubation Experiments ◽

Phenolic Group ◽

Capacity Data ◽

Group Concentration

Chars intended for use as soil amendment (“biochars”) vary greatly in their chemical and physical properties. In the present study, 19 Canadian temperate wood feedstocks were charred across a range of pyrolysis temperatures from 300–700 °C. The resulting 95 biochars were tested for their physio-chemical properties and liming capacity. Data indicated increasing base cation concentrations including Ca, Mg, and K (elements that characteristically form liming compounds, i.e., carbonates) as pyrolysis temperature increased. Acidic surface functional groups were analyzed with modified Boehm titration: Carboxylic and lactonic functional group concentrations decreased and phenolic group concentration increased with pyrolysis temperature. Functional group composition also varied greatly with feedstock: In particular, conifer-derived biochars produced at pyrolysis temperatures <500 °C showed much higher carboxylic and lactonic functional group concentrations than did angiosperm-derived biochars. Liming capacity was assessed using soil incubation experiments and was positively related to biochar pH. Both acidic surface functional group concentration and nutrient element concentration influenced biochar pH: we developed a non-linear functional relationship that predicts biochar pH from the ratio of carboxylic to phenolic moieties, and concentrations of Ca and K. Biochar’s liming components that are inherited from feedstock and predictably modified by pyrolysis temperature provide a basis for optimizing the production of biochar with desired pH and liming characteristics.

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Timolol-imprinted soft contact lenses: Influence of the template: Functional monomer ratio and the hydrogel thickness

Journal of Applied Polymer Science ◽

10.1002/app.34022 ◽

2011 ◽

Vol 122 (2) ◽

pp. 1333-1340 ◽

Cited By ~ 22

Author(s):

Fernando Yañez ◽

Anuj Chauhan ◽

Angel Concheiro ◽

Carmen Alvarez-Lorenzo

Keyword(s):

Contact Lenses ◽

Functional Monomer ◽

Soft Contact ◽

Soft Contact Lenses ◽

Monomer Ratio

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Immobilization of polyisobutene in semi-interpenetrating polymer network architecture

Polymer ◽

10.1016/j.polymer.2010.09.015 ◽

2010 ◽

Vol 51 (23) ◽

pp. 5323-5331 ◽

Cited By ~ 3

Author(s):

Benjamin Davion ◽

Cédric Vancaeyzeele ◽

Odile Fichet ◽

Dominique Teyssié

Keyword(s):

Network Architecture ◽

Polymer Network ◽

Interpenetrating Polymer Network

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The Influence of Lignin Diversity on the Structural and Thermal Properties of Polymeric Microspheres Derived from Lignin, Styrene, and/or Divinylbenzene

Materials ◽

10.3390/ma12182847 ◽

2019 ◽

Vol 12 (18) ◽

pp. 2847 ◽

Cited By ~ 2

Author(s):

Marta Goliszek ◽

Beata Podkościelna ◽

Olena Sevastyanova ◽

Barbara Gawdzik ◽

Artur Chabros

Keyword(s):

Thermal Properties ◽

Structural Characteristics ◽

Polymer Network ◽

Eucalyptus Grandis ◽

Nitrogen Adsorption ◽

Optical Microscope ◽

Scanning Calorimetry ◽

Promising Alternative ◽

Synthetic Materials ◽

The Impact

This work investigates the impact of lignin origin and structural characteristics, such as molecular weight and functionality, on the properties of corresponding porous biopolymeric microspheres obtained through suspension-emulsion polymerization of lignin with styrene (St) and/or divinylbenzene (DVB). Two types of kraft lignin, which are softwood (Picea abies L.) and hardwood (Eucalyptus grandis), fractionated by common industrial solvents, and related methacrylates, were used in the synthesis. The presence of the appropriate functional groups in the lignins and in the corresponding microspheres were investigated by attenuated total reflectance Fourier transform infrared spectroscopy (ATR/FT-IR), while the thermal properties were studied by differential scanning calorimetry (DSC). The texture of the microspheres was characterized using low-temperature nitrogen adsorption. The swelling studies were performed in typical organic solvents and distilled water. The shapes of the microspheres were confirmed with an optical microscope. The introduction of lignin into a St and/or DVB polymeric system made it possible to obtain highly porous functionalized microspheres that increase their sorption potential. Lignin methacrylates created a polymer network with St and DVB, whereas the unmodified lignin acted mainly as an eco-friendly filler in the pores of St-DVB or DVB microspheres. The incorporation of biopolymer into the microspheres could be a promising alternative to a modification of synthetic materials and a better utilization of lignin.

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