Interpenetrating polydicyclopentadiene/polyacrylate networks obtained by simultaneous non-interfering frontal polymerization

e-Polymers ◽  
2002 ◽  
Vol 2 (1) ◽  
Author(s):  
Stefano Fiori ◽  
Alberto Mariani ◽  
Laura Ricco ◽  
Saverio Russo
Keyword(s):  
Free Radical ◽  
Polymer Networks ◽  
Interpenetrating Polymer Networks ◽  
Front Velocity ◽  
Frontal Polymerization ◽  
Maximum Temperature ◽  
Glycol Dimethacrylate ◽  
Monomer Ratio ◽  
Free Radical Initiator

AbstractInterpenetrating polymer networks made of dicyclopentadiene and methyl methacrylate or tri(ethylene glycol) dimethacrylate have been successfully prepared by non-interfering frontal polymerization. The role of catalyst and free radical initiator relative amounts, as well as of monomer ratio, has been thoroughly studied. The conditions under which a pure frontal polymerization occurs, and the related values of both front velocity and maximum temperature reached by the reaction, are presented and discussed.

Synthesis and characterization of a polyester/styrene resin obtained by frontal polymerization

e-Polymers ◽  
2002 ◽  
Vol 2 (1) ◽  
Author(s):  
Stefano Fiori ◽  
Giulio Malucelli ◽  
Alberto Mariani ◽  
Laura Ricco ◽  
Elena Casazza
Keyword(s):  
Free Radical ◽  
Mechanical Behaviour ◽  
Unsaturated Polyester ◽  
Front Velocity ◽  
Frontal Polymerization ◽  
Maximum Temperature ◽  
Synthesis And Characterization ◽  
Free Radical Initiator ◽  
First Time

AbstractThe frontal polymerization technique has been successfully applied, for the first time, to obtain an unsaturated polyester/styrene resin. The effect of the ratio of the two aforementioned components, as well as of the type and amount of free-radical initiator on both front velocity and maximum temperature reached by the front, has been thoroughly studied. The resulting products have been characterized in terms of their thermal and dynamic-mechanical behaviour. A comparison of such products with the corresponding materials obtained by the classical batch polymerization technique has evidenced that frontal polymerization allows to reach a higher degree of crosslinking with respect to batch copolymerization and hence a better thermal and mechanical behaviour.

scholarly journals Microbiological-Chemical Sourced Chondroitin Sulfates Protect Neuroblastoma SH-SY5Y Cells against Oxidative Stress and Are Suitable for Hydrogel-Based Controlled Release

Antioxidants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1816
Author(s):  
Emiliano Bedini ◽  
Alfonso Iadonisi ◽  
Chiara Schiraldi ◽  
Laura Colombo ◽  
Diego Albani ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Neuroprotective Effect ◽  
Polymer Networks ◽  
Interpenetrating Polymer Networks ◽  
Ethical Concerns ◽  
Chondroitin Sulfates ◽  
Sulfation Pattern ◽  
Pre Treatment ◽  
Set Up

Chondroitin sulfates (CS) are a class of sulfated glycosaminoglycans involved in many biological processes. Several studies reported their protective effect against neurodegenerative conditions like Alzheimer’s disease. CS are commonly derived from animal sources, but ethical concerns, the risk of contamination with animal proteins, and the difficulty in controlling the sulfation pattern have prompted research towards non-animal sources. Here we exploited two microbiological-chemical sourced CS (i.e., CS-A,C and CS-A,C,K,L) and Carbopol 974P NF/agarose semi-interpenetrating polymer networks (i.e., P.NaOH.0 and P.Ethanol.0) to set up a release system, and tested the neuroprotective role of released CS against H2O2-induced oxidative stress. After assessing that our CS (1–100 µM) require a 3 h pre-treatment for neuroprotection with SH-SY5Y cells, we evaluated whether the autoclave type (i.e., N- or B-type) affects hydrogel viscoelastic properties. We selected B-type autoclaves and repeated the study after loading CS (1 or 0.1 mg CS/0.5 mL gel). After loading 1 mg CS/0.5 mL gel, we evaluated CS release up to 7 days by 1,9-dimethylmethylene blue (DMMB) assay and verified the neuroprotective role of CS-A,C (1 µM) in the supernatants. We observed that CS-A,C exhibits a broader neuroprotective effect than CS-A,C,K,L. Moreover, sulfation pattern affects not only neuroprotection, but also drug release.

Frontal atom transfer radical polymerization of tri(ethylene glycol) dimethacrylate

e-Polymers ◽  
2003 ◽  
Vol 3 (1) ◽  
Author(s):  
Simone Bidali ◽  
Stefano Fiori ◽  
Giulio Malucelli ◽  
Alberto Mariani
Keyword(s):  
Ethylene Glycol ◽  
Atom Transfer Radical Polymerization ◽  
Radical Polymerization ◽  
Reaction Times ◽  
Frontal Polymerization ◽  
Ethylene Glycol Dimethacrylate ◽  
Maximum Temperature ◽  
Atom Transfer ◽  
Glycol Dimethacrylate ◽  
Degradation Temperature

Abstract The first frontal atom transfer radical polymerization (FATRP) has been successfully carried out using tri(ethylene glycol) dimethacrylate as a monomer. The effect of the catalyst/initiator ratio has been investigated and related to the front velocity and its maximum temperature. By comparing this new approach with classical radical polymerization routes and with conventional frontal polymerization, it was found that the so-obtained polymer is characterized by higher conversion, shorter reaction times, higher degradation temperature, and does not contain entrapped bubbles.

scholarly journals Mutual sensibilization in epoxyacrylate interpenetrating polymer networks

2021 ◽  
pp. 149-158
Author(s):  
Oleksandr O. Brovko ◽  
◽  
Natalia V. Yarova ◽  
Tetiana F. Samoilenko ◽  
Larysa M. Yashchenko ◽  
...  
Keyword(s):  
Free Radical ◽  
Polymer Networks ◽  
Triethylene Glycol ◽  
Interpenetrating Polymer Networks ◽  
Degree Of Conversion ◽  
Epoxy Acrylate ◽  
Low Viscosity ◽  
First Case ◽  
Sensitizing Effect ◽  
Epoxy Groups

Using the method of IR spectroscopy, the kinetic features of the course of photoinitiated cationic and free radical polymerization in simultaneous epoxyacrylate interpenetrating polymer networks were investigated. The degree and rate of conversion of epoxy groups in the epoxy component (aliphatic diepoxide UP-650D, aliphatic-alicyclic triepoxide UP-650T, and diane epoxides ED-20 and Epicot 828), and the opening of double bonds in acrylate component (triethylene glycol dimethacrylate) were determined. The sensitizing effect of the acrylate component on the degree of conversion of epoxy groups in IPNs with aliphatic diepoxide or aliphatic-alicyclic triepoxide with an epoxy/acrylate ratio of 50/50 wt. % was revealed. For diane epoxies, the opposite regularity of conversion of epoxy groups in the composition of epoxy-acrylate IPNs is observed: in comparison with initial polymer networks, the degree of conversion of epoxy groups was significantly reduced. In the first case of low-viscosity aliphatic and cycloaliphatic epoxides such a sensitization is occurred due to the fact that the simultaneous polymerization of acrylate via a free radical mechanism promotes the decomposition of the photoinitiator and the formation of more macrocations quantity. In second case of more viscous diane epoxy resins, the spatial restriction imposed by the rapidly formed acrylate networks is predominate. That is why the conversion of epoxy groups is reduced and this effect is neutralized.

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