Role of graded length side chains up to 18 carbons in length on the damping behavior of polyurethane/epoxy interpenetrating polymer networks

2013 ◽  
Vol 49 (6) ◽  
pp. 1731-1741 ◽  
Author(s):  
Wenwen Yu ◽  
Dezhi Zhang ◽  
Miao Du ◽  
Qiang Zheng
Antioxidants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1816
Author(s):  
Emiliano Bedini ◽  
Alfonso Iadonisi ◽  
Chiara Schiraldi ◽  
Laura Colombo ◽  
Diego Albani ◽  
...  

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.


e-Polymers ◽  
2002 ◽  
Vol 2 (1) ◽  
Author(s):  
Stefano Fiori ◽  
Alberto Mariani ◽  
Laura Ricco ◽  
Saverio Russo

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.


1986 ◽  
Vol 59 (2) ◽  
pp. 255-262 ◽  
Author(s):  
D. G. Fradkin ◽  
J. N. Foster ◽  
L. H. Sperling ◽  
D. A. Thomas

Abstract The damping function, D.F., as derived from the area under the linearE″— temperature curve, expresses the amount of mechanical energy converted to heat per unit volume of material. Sometimes characteristics of the damping behavior of homopolymers and IPN's are more apparent in the linear E″—temperature plot, such as glass transitions and secondary transitions. Decrosslinking and/or annealing the IPN's have no effect on the D.F.'s, although these treatments significantly modify the shape of the E″—temperature curves as a result of molecular and phase rearrangements. Thus, to a first approximation, the area expressed by D.F. is a polymer chain characteristic, depending on the chain structure itself but not on crosslinking and/or annealing.


2019 ◽  
Vol 545 ◽  
pp. 210-219 ◽  
Author(s):  
Valentina Nigro ◽  
Roberta Angelini ◽  
Benedetta Rosi ◽  
Monica Bertoldo ◽  
Elena Buratti ◽  
...  

Author(s):  
Mei Rui Fu ◽  
Yang You ◽  
Min Zhi Rong ◽  
Ming Qiu Zhang

The recently developed reversibly interlocked polymer networks are made from two-pre-formed crosslinked polymers containing reversible covalent bonds via topological rearrangement. Unlike interpenetrating polymer networks, the resultant is rather homogeneous regardless...


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