Radiation-Induced Graft Polymerization of Maleic Anhydride onto Poly-β-Hydroxybutyrate

2005 ◽  
Vol 288-289 ◽  
pp. 477-480 ◽  
Author(s):  
Herong Ye ◽  
Dongzhi Yang ◽  
Ping Hu ◽  
Feng Bo Zhang ◽  
Qinglei Qi
Keyword(s):  
Molecular Weight ◽  
Maleic Anhydride ◽  
Graft Polymerization ◽  
Average Molecular Weight ◽  
Commercial Application ◽  
Radiation Induced

This paper focuses on an effective way to improve the thermostability of poly-β-hydroxybutyrate (PHB). Maleic anhydride (MA) is grafted onto PHB by 60Co γ of radiation. The spectra of both 1HNMR and 13CNMR were investigated following the radiation-induced polymerization. The results are consistent with successful grafting of the MA monomer onto the PHB, with a low graft degree. The graft degree and viscosity-average molecular weight Mηof the radiated samples were also investigated. The results observed through TGA demonstrate that thermostability has been measurably improved with the introduction of MA groups. These significant results suggest that wide commercial application of PHB may be possible.

scholarly journals Self-Stable Precipitation Polymerization Molecular Entanglement Effect and Molecular Weight Simulations and Experiments

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2243
Author(s):  
Jiali Qu ◽  
Yi Gao ◽  
Wantai Yang
Keyword(s):  
Molecular Weight ◽  
Maleic Anhydride ◽  
Molecular Conformation ◽  
Average Molecular Weight ◽  
Precipitation Polymerization ◽  
Radius Of Gyration ◽  
Propagation Mechanism ◽  
Reactive Molecular Dynamics ◽  
End Distance ◽  
Good Agreement

In this paper, we developed a reactive molecular dynamics (RMD) scheme to simulate the Self-Stable Precipitation (SP) polymerization of 1-pentene and cyclopentene (C5) with maleic anhydride (MAn) in an all-atom resolution. We studied the chain propagation mechanism by tracking the changes in molecular conformation and analyzing end-to-end distance and radius of gyration. The results show that the main reason of chain termination in the reaction process was due to intramolecular cyclic entanglement, which made the active center wrapped in the center of the globular chain. After conducting the experiment in the same condition with the simulation, we found that the distribution trend and peak value of the molecular-weight-distribution curve in the simulation were consistent with experimental results. The simulated number average molecular weight (Mn) and weight average molecular weight (Mw) were in good agreement with the experiment. Moreover, the simulated molecular polydispersity index (PDI) for cyclopentene reaction with maleic anhydride was accurate, differing by 0.04 from the experimental value. These show that this model is suitable for C5–maleic anhydride self-stable precipitation polymerization and is expected to be used as a molecular weight prediction tool for other maleic anhydride self-stable precipitation polymerization system.

scholarly journals Valonea Tannin: Tyrosinase Inhibition Activity, Structural Elucidation and Insights into the Inhibition Mechanism

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2747
Author(s):  
Jiaman Liu ◽  
Yuqing Liu ◽  
Xiaofeng He ◽  
Bo Teng ◽  
Jacqui M. McRae
Keyword(s):  
Molecular Weight ◽  
Structure Function ◽  
Hydrophobic Interactions ◽  
Average Molecular Weight ◽  
Commercial Application ◽  
Inhibition Mechanism ◽  
Resonance Spectroscopy ◽  
Inhibition Activity ◽  
Tyrosinase Inhibition ◽  
Function Activity

Valonea tannin is a natural product readily extracted from acorn shells that has been suggested to have potential skin whitening properties. This study investigated the tyrosinase inhibition activity of extracted valonea tannin and the associated structure–function activity. Nuclear magnetic resonance spectroscopy and molecular weight analysis with gel permeation chromatography revealed that valonea tannin could be characterized as a hydrolysable tannin with galloyl, hexahydroxydiphenoyl and open formed-glucose moieties and an average molecular weight of 3042 ± 15 Da. Tyrosinase inhibition assays demonstrated that valonea tannin was 334 times more effective than gallic acid and 3.4 times more effective than tannic acid, which may relate to the larger molecular size. Kinetic studies of the inhibition reactions indicated that valonea tannin provided tyrosinase inhibition through mixed competitive–uncompetitive way. Stern–Volmer fitted fluorescence quenching analysis, isothermal titration calorimetry analysis and in silico molecule docking showed valonea tannin non-selectively bound to the surface of tyrosinase via hydrogen bonds and hydrophobic interactions. Inductively coupled plasma-optical emission spectroscopy and free radical scavenging assays indicated the valonea tannin had copper ion chelating and antioxidant ability, which may also contribute to inhibition activity. These results demonstrated the structure–function activity of valonea tannin as a highly effective natural tyrosinase inhibitor that may have commercial application in dermatological medicines or cosmetic products.

Molecular weight distribution of methyl methacrylate grafted onto a microfiltration membrane by radiation-induced graft polymerization

1993 ◽  
Vol 85 (1) ◽  
pp. 71-80 ◽  
Author(s):  
Hideyuki Yamagishi ◽  
Kyoichi Saito ◽  
Shintaro Furusaki ◽  
Takanobu Sugo ◽  
Fumio Hosoi ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Methyl Methacrylate ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Graft Polymerization ◽  
Microfiltration Membrane ◽  
Radiation Induced

Enhanced ionic polymerization of styrene induced by radiation

1963 ◽  
Vol 273 (1354) ◽  
pp. 387-399 ◽  
Keyword(s):  
Molecular Weight ◽  
Radiation Intensity ◽  
Chain Transfer ◽  
Average Molecular Weight ◽  
Surface Adsorption ◽  
Silica Powder ◽  
Intensity Dependence ◽  
Radiation Induced

The radiation-induced ionic polymerization of styrene at — 78 °C has been studied, at various concentrations in diehloromethane solutions, in the presence of silica powder, and at various radiation intensities. Both yield of polymer, and average molecular weight were determined, allowing an estimate of G i for ionic polymerization to be made. The yield is greatly reduced by traces of water and this is ascribed to increased termination. On the assumption that chain transfer is small, Aerosil powder appears to cause an increase in initiation, rather than a reduction in termination. Evidence is presented for the view that the enhanced reaction occurs by the surface adsorption of styrene ions, so that the radiation intensity dependence changes from I 1.0 to I 0.5 . Energy absorbed in the solvent is also found to be capable of initiation.

scholarly journals Use of a Styrene-Maleic Anhydride Copolymer as an Adjuvant with Testosterone-Serum Albumin Immunogens and its Application to Increasing Ovulation Rate in the Ewe

1986 ◽  
Vol 39 (1) ◽  
pp. 99
Author(s):  
MSF Wong ◽  
RM Hoskinson ◽  
RI COX ◽  
D O Hawthorne ◽  
DH Solomon ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Maleic Anhydride ◽  
Antibody Response ◽  
Serum Albumin ◽  
Average Molecular Weight ◽  
Ovulation Rate ◽  
Binding Antibody ◽  
Styrene Maleic Anhydride ◽  
Maleic Anhydride Copolymer

A synthetic poly(styrene-maleic anhydride) copolymer of average molecular weight 470000 potentiated a testosterone-binding antibody response during immunization of sheep with immunogenic testosterone- 3-carboxymethyloxime-serum albumin conjugates.

Radiation-Induced Graft Polymerization of Maleic Anhydride onto Poly-β-Hydroxybutyrate

2005 ◽  
pp. 477-480
Author(s):  
Herong Ye ◽  
Dongzhi Yang ◽  
Ping Hu ◽  
Feng Bo Zhang ◽  
Qinglei Qi
Keyword(s):  
Maleic Anhydride ◽  
Graft Polymerization ◽  
Radiation Induced

Radiation-induced graft polymerization of maleic acid and maleic anhydride onto ultra-fine powdered styrene–butadiene rubber (UFSBR)

2007 ◽  
Vol 76 (11-12) ◽  
pp. 1741-1745 ◽  
Author(s):  
Jing Peng ◽  
Haibing Xia ◽  
Maolin Zhai ◽  
Jiuqiang Li ◽  
Jinliang Qiao ◽  
...  
Keyword(s):  
Maleic Anhydride ◽  
Maleic Acid ◽  
Graft Polymerization ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Radiation Induced ◽  
Styrene Butadiene

The Structure of Radiation Cross-Linked Poly (ethylene oxide) Gels

1971 ◽  
Vol 29 ◽  
pp. 76-77
Author(s):  
C. E. Cluthe ◽  
G. G. Cocks
Keyword(s):  
Molecular Weight ◽  
Ethylene Oxide ◽  
Parallel Plate ◽  
Average Molecular Weight ◽  
Radical Reaction ◽  
Free Radical Reaction ◽  
Nitrogen Gas ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
Initial Viscosity

Aqueous solutions of a 1 weight-per cent poly (ethylene oxide) (PEO) were degassed under vacuum, transferred to a parallel plate viscometer under a nitrogen gas blanket, and exposed to Co60 gamma radiation. The Co60 source was rated at 4000 curies, and the dose ratewas 3.8x105 rads/hr. The poly (ethylene oxide) employed in the irradiations had an initial viscosity average molecular weight of 2.1 x 106.The solutions were gelled by a free radical reaction with dosages ranging from 5x104 rads to 4.8x106 rads.

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