Synthetic and semi-synthetic polymers for pharmaceutical applications

Rubber stocks, specially tires, are composed of natural rubber and synthetic polymers and also of several compounding ingredients, such as carbon black, silica, zinc oxide etc. These are generally mixed and vulcanized with additional curing agents, mainly organic in nature, to achieve certain “designing properties” including wear, traction, rolling resistance and handling of tires. Considerable importance is, therefore, attached both by the manufacturers and their competitors to be able to extract, identify and characterize various types of fillers and pigments. Several analytical procedures have been in use to extract, preferentially, these fillers and pigments and subsequently identify and characterize them under a transmission electron microscope.Rubber stocks and tire sections are subjected to heat under nitrogen atmosphere to 550°C for one hour and then cooled under nitrogen to remove polymers, leaving behind carbon black, silica and zinc oxide and 650°C to eliminate carbon blacks, leaving only silica and zinc oxide.

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Characterization of Synthetic Polymers Using Matrix-Assisted Laser Desorption/Ionization−Time of Flight Mass Spectrometry Volume 29, Number 6, March 11, 1996, pp 2213−2221

Macromolecules ◽

10.1021/ma9520151 ◽

1996 ◽

Vol 29 (18) ◽

pp. 6080-6080 ◽

Cited By ~ 1

Author(s):

Apurva K. Chaudhary ◽

Glenn Critchley ◽

Abderhammane Diaf ◽

Eric J. Beckman ◽

Alan J. Russell

Keyword(s):

Mass Spectrometry ◽

Laser Desorption ◽

Synthetic Polymers ◽

Laser Desorption Ionization ◽

Ionization Time ◽

Desorption Ionization ◽

Flight Mass Spectrometry ◽

Matrix Assisted Laser ◽

Matrix Assisted Laser Desorption

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Simple Modification Measurement of Photodegradability of Polymers by using Photo-induced Chemiluminescence Technique

Scientific Research Journal ◽

10.24191/srj.v10i2.5414 ◽

2013 ◽

Vol 10 (2) ◽

pp. 51

Author(s):

Siti Farhana Zakaria ◽

Keith R Millington

Keyword(s):

Free Radicals ◽

Organic Materials ◽

Oxidative Degradation ◽

Working Life ◽

Bimolecular Reaction ◽

Synthetic Polymers ◽

Accelerated Weathering ◽

Simple Modification ◽

Uv Absorbers ◽

Irradiation Period

Polymers and organic materials that are exposed to sunlight undergo photooxidation, which leads to deterioration of their physical properties. To allow adequate performance under outdoor conditions, synthetic polymers require additives such as antioxidants and UV absorbers. A major problem with optimising polymer formulations to maximise their working life span is that accelerated weathering tests are empirical. The conditions differ significantly from real weathering situations, and samples require lengthy irradiation period. Degradation may not be apparent in the early stages of exposure, although this is when products such as hydroperoxides are formed which later cause acceleration of oxidation. A simple way of quantifying the number of free radicals presents in organic materials following exposure to light or heat is by measuring chemiluminescence (CL) emission. Most polymers emit CL when they undergo oxidative degradation, and it originates from the bimolecular reaction of macroperoxy radicals which creates an excited carbonyl.

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Pharmaceutical Polymers - A Review

International Journal of Drug Delivery Technology ◽

10.25258/ijddt.9.1.5 ◽

2019 ◽

Vol 9 (01) ◽

pp. 27-33

Author(s):

Naveen Kumar ◽

Sonia Pahuja ◽

Ranjit Sharma

Keyword(s):

Drug Release ◽

Industrial Revolution ◽

Pharmaceutical Formulations ◽

Pharmaceutical Products ◽

Water Soluble ◽

Taste Masking ◽

Natural Polymers ◽

Pharmaceutical Dosage Forms ◽

Pharmaceutical Applications ◽

Pharmaceutical Industries

Humans have taken advantage of the adaptability of polymers for centuries in the form of resins, gums tars, and oils. However, it was not until the industrial revolution that the modern polymer industry began to develop. Polymers represent an important constituent of pharmaceutical dosage forms. Polymers have played vital roles in the formulation of pharmaceutical products. Polymers have been used as a major tool to manage the drug release rate from the formulations. Synthetic and natural-based polymers have found their way into the biomedical and pharmaceutical industries. Synthetic and Natural polymers can be produced with a broad range of strength, heat resistance, density, stiffness and even price. By constant research into the science and applications of polymers, they are playing an ever-increasing role in society. Diverse applications of polymers in the present pharmaceutical field are for controlled drug release. Based on solubility pharmaceutical polymers can be classified as water-soluble and water-insoluble. In general, the desirable polymer properties in pharmaceutical applications are film forming, adhesion, gelling, thickening, pH-dependent solubility and taste masking. General pharmaceutical applications of polymers in various pharmaceutical formulations are also discussed

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Cooperative Self-Assembly of Pyridine-2,6-Diimine-Linked Macrocycles into Mechanically Robust Nanotubes

10.26434/chemrxiv.8080043 ◽

2019 ◽

Author(s):

Michael J. Strauss ◽

Darya Asheghali ◽

Austin Evans ◽

Rebecca Li ◽

Anton Chavez ◽

...

Keyword(s):

Aspect Ratio ◽

High Aspect Ratio ◽

Self Assembly ◽

Gel Permeation Chromatography ◽

Synthetic Polymers ◽

Young’S Moduli ◽

Structural Rigidity ◽

Assembly Mechanism ◽

Low Dimensionality ◽

Harsh Conditions

Nanotubes assembled from macrocyclic precursors offer a unique combination of low dimensionality, structural rigidity, and distinct interior and exterior microenvironments. Usually the weak stacking energies of macrocycles limit the length or strength of the resultant nanotubes. Imine-linked macrocycles were recently found to assemble into high-aspect ratio (>103), lyotropic nanotubes in the presence of excess acid. Yet these harsh conditions are incompatible with many functional groups and processing methods, and lower acid loadings instead catalyze macrocycle degradation. Here we report pyridine-2,6-diimine-linked macrocycles that assemble into high-aspect ratio nanotubes in the presence of less than 1 equiv of CF3CO2H per macrocycle. Analysis by gel permeation chromatography and fluorescence spectroscopy revealed a cooperative self-assembly mechanism. Nanofibers obtained by touch-spinning the pyridinium-based nanotubes exhibit Young’s moduli of 1.48 GPa, which exceeds that of many synthetic polymers and biological filaments. These findings will enable the design of structurally diverse nanotubes from synthetically accessible macrocycles.

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