The Mechanochemical Breakdown of Polystyrene by Vibromilling

1961 ◽  
Vol 34 (2) ◽  
pp. 474-481 ◽  
Author(s):  
H. Grohn ◽  
K. Bischof
Keyword(s):  
Melting Point ◽  
Block Copolymers ◽  
Infrared Spectra ◽  
Science And Technology ◽  
Polymer Materials ◽  
Graft Polymers

Abstract The investigation presented here, including detection of nitrogen, the viscometric investigation, melting point determinations, the ultraviolet and infrared spectra, allow of the qualitative statement that macroradicals are formed in the mechanochemical breakdown of polystyrene by vibromilling. The slight differences between N2 and NO milling may be ascribed in part to a more rapid deactivation of the radicals. On the foundation of the existing knowledge of mechanochemistry there result interesting prospects for science and technology, e.g., the use of macro-radicals as polymerization initiators and as active types of block copolymers and graft polymers by reactions both with monomers and with macroradicals of other polymer materials.

NIKOLAY SEMENOVICH LEZNOV: BIOGRAPHY AND CONTRIBUTION TO THE DEVELOPMENT OF SCIENCE

2021 ◽  
pp. 112-124
Author(s):  
N.S. Kitaeva ◽  
◽  
Yu.M. Shiryakina ◽  
R.R. Mukhametov ◽  
R.O. Shitov ◽  
...  
Keyword(s):  
Science And Technology ◽  
Polymer Materials ◽  
Life Stages ◽  
Metallic Materials ◽  
Chemical Studies ◽  
Physical And Chemical

The main life stages of a doctor of technical sciences, professor, honored worker of science and technology of the RSFSR, a major specialist in the field of creation and implementation of polymers for new aviation materials, whose name was Nikolai Semenovich Leznov (12/17/1904–06/25/1984), were considered. The scientific works and achievements of the founder of the laboratory for the synthesis of polymers, binders for non-metallic materials, special liquids and physical and chemical studies of polymer materials of VIAM were analyzed and described.

Elastomeric Polyether-Ester Block Copolymers. I. Structure-Property Relationships of Tetramethylene Terephthalate/Polyether Terephthalate Copolymers

1977 ◽  
Vol 50 (4) ◽  
pp. 688-703 ◽  
Author(s):  
J. R. Wolfe
Keyword(s):  
Phase Separation ◽  
Melting Point ◽  
Block Copolymers ◽  
Low Temperature ◽  
Chain Length ◽  
Chemical Structure ◽  
High Water ◽  
Structure Property ◽  
Tear Strength ◽  
Structure Property Relationships

Abstract The properties of elastomeric tetramethylene terephthalate/polyether terephthalate copolymers have been related to the chemical structure, chain length, and concentration in the copolymers of the PTMEG-, PEG-, and PPG-derived polyether units. Low-temperature properties and tear strength are dependent on all three polyether-related variables. Melting point, hardness, and stress at 100% elongation appear to be independent of polyether structure. Polyether glycols of low MW volatilize during copolymer preparation. High-MW polyethers tend to crystallize when present in the copolymers. Polyether glycols of intermediate MW (∼ 1000) yield copolymers with the best resistance to low-temperature stiffening. Copolymer synthesis is most difficult with PPG as the polyether glycol. Inherent viscosities are low, and phase separation occurs at lower polyether MW than with PTMEG or PEG. The PEG-based copolymers exhibit high water swell, particularly at intermediate and high PEG MW. The PTMEG-based copolymers are easiest to synthesize and exhibit the best overall combination of properties.

scholarly journals In Vitro and In Vivo Studies of Biodegradability and Biocompatibility of Poly(εCL)-b-Poly(EtOEP)-Based Films

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3039
Author(s):  
Ilya Nifant’ev ◽  
Andrey Shlyakhtin ◽  
Pavel Komarov ◽  
Alexander Tavtorkin ◽  
Evgeniya Kananykhina ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Block Copolymers ◽  
Polymer Films ◽  
Hydrolytic Stability ◽  
Polymer Materials ◽  
In Vivo Studies ◽  
Cytotoxicity Test ◽  
The Impact

The control of surface bioadhesive properties of the subcutaneous implants is essential for the development of biosensors and controlled drug release devices. Poly(alkyl ethylene phosphate)-based (co)polymers are structurally versatile, biocompatible and biodegradable, and may be regarded as an alternative to poly(ethylene glycol) (PEG) copolymers in the creation of antiadhesive materials. The present work reports the synthesis of block copolymers of ε-caprolactone (εCL) and 2-ethoxy-1,3,2-dioxaphospholane-2-oxide (ethyl ethylene phosphate, EtOEP) with different content of EtOEP fragments, preparation of polymer films, and the results of the study of the impact of EtOEP/εCL ratio on the hydrophilicity (contact angle of wetting), hydrolytic stability, cytotoxicity, protein and cell adhesion, and cell proliferation using umbilical cord multipotent stem cells. It was found that the increase of EtOEP/εCL ratio results in increase of hydrophilicity of the polymer films with lowering of the protein and cell adhesion. MTT cytotoxicity test showed no significant deviations in toxicity of poly(εCL) and poly(εCL)-b-poly(EtOEP)-based films. The influence of the length of poly(EtOEP)chain in block-copolymers on fibrotic reactions was analyzed using subcutaneous implantation experiments (Wistar line rats), the increase of the width of the fibrous capsule correlated with higher EtOEP/εCL ratio. However, the copolymer-based film with highest content of polyphosphate had been subjected to faster degradation with a formation of developed contact surface of poly(εCL). The rate of the degradation of polyphosphate in vivo was significantly higher than the rate of the degradation of polyphosphate in vitro, which only confirms an objective value of in vivo experiments in the development of polymer materials for biomedical applications.

Structures and morphologies of biocompatible and biodegradable block copolymers

RSC Advances ◽  
2014 ◽  
Vol 4 (47) ◽  
pp. 24566-24583 ◽  
Author(s):  
Shaoyong Huang ◽  
Shichun Jiang
Keyword(s):  
Block Copolymers ◽  
Polymer Materials ◽  
Polymer Science ◽  
Potential Applications

Biocompatible and biodegradable block copolymers (BBCPs) have become increasingly important in polymer science, and have many potential applications in polymer materials.

scholarly journals Recent Progress in Polymer-Based Building Materials

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Jingjing Shen ◽  
Jianwei Liang ◽  
Xinfeng Lin ◽  
Hongjian Lin ◽  
Jing Yu ◽  
...  
Keyword(s):  
Functional Properties ◽  
Material Science ◽  
Flame Retardants ◽  
Building Materials ◽  
Recent Progress ◽  
Science And Technology ◽  
Functional Materials ◽  
Inorganic Materials ◽  
Polymer Materials ◽  
Human Society

With the development of human society, the requirements for building materials are becoming higher. The development of polymer materials and their application in the field of architecture have greatly enhanced and broadened the functions of building materials. With the development of material science and technology, many functional materials have been developed. Polymer materials have many excellent properties compared with inorganic materials, and they can also be improved to enhance functional properties by blending or adding various additives (such as flame retardants, antistatic agents, and antioxidants). In this paper, polymer-based building materials are introduced with three classes according to the applications, that is, substrates, coatings, and binders, and their recent signs of progress in the preparations and applications are carefully demonstrated.

RAMAN AND INFRARED STUDY OF PHASE TRANSFORMATION IN CRYSTALLINE HYDROGEN IODIDE AND DEUTERIUM IODIDE HI AND DI

1989 ◽  
Vol 03 (11) ◽  
pp. 1671-1679 ◽  
Author(s):  
W.S. TSE ◽  
C.S. FANG ◽  
A. ANDERSON ◽  
B.H. TORRIE
Keyword(s):  
Phase Transformation ◽  
Phase Transitions ◽  
Melting Point ◽  
Infrared Spectra ◽  
Hydrogen Iodide ◽  
Temperature Dependent ◽  
Two Phase ◽  
Infrared Study ◽  
X Ray ◽  
Temperature Range

Raman and infrared spectra of polycrystalline HI and DI in the region of lattice and internal modes for all three phases have been recorded over the temperature range 18 K to the melting point. The temperature dependent Raman and infrared results are consistent with the X-ray and neutron work that two phase transitions occur at HI and DI involving reorientation of the HI and DI molecules as a whole.

The Application of Polymer Materials with High Mechanical Properties in Competitive Sports

2014 ◽  
Vol 1028 ◽  
pp. 337-340
Author(s):  
Ning Li
Keyword(s):  
Mechanical Properties ◽  
Science And Technology ◽  
Social Activity ◽  
Polymer Materials ◽  
Competitive Sports ◽  
New Materials ◽  
Material Type ◽  
Important Material

With the development of science and technology, the requirements on the properties of new materials was increasing, polymer materials become one kind of important material type which has been widely used in the current human social activity. Due to its high properties such as strength, elasticity and toughness, polymer materials with high mechanical properties’ application in the field of competitive sports has incomparable advantages. This paper analyzes the characteristics of high mechanical properties of polymer materials and its advantage in competitive sports, in order to promote its application in the field of sports.

Analysis of the Structures and Thermal Properties of Hexanediamine Adipate and Pentanediamine Adipate

2018 ◽  
Vol 876 ◽  
pp. 76-83
Author(s):  
Xiao Wan Yang ◽  
Xin Min Hao ◽  
Jian Ming Wang ◽  
Yan Bin Liu ◽  
Hong Liang Kang
Keyword(s):  
Thermal Properties ◽  
Melting Point ◽  
Infrared Spectra ◽  
Adipic Acid ◽  
Decomposition Temperature ◽  
Bending Vibration ◽  
Out Of Plane ◽  
Stretching Vibration ◽  
Acid Reaction ◽  
The Difference

Hexanediamine adipate, pentanediamine adipate and bio-based pentanediamine adipate were prepared by adipic acid reaction with 1,6-hexanediamine, 1,5-pentanediamine and bio-based 1,5-pentanediamine, respectively. Their structures and thermal properties have been analyzed by infrared spectra, SEM, DSC and TGA. Infrared spectra showed the main differences between 1,6-hexanediamine and 1,5-pentanediamine for the deformation vibration and out of plane bending vibration of N−H. Hexanediamine adipate and pentanediamine adipate had the difference at the asymmetric stretching vibration of −COO-−. The crystal morphologies of hexanediamine adipate and pentanediamine adipate showed dendritic and acicular, respectively. The melting point of pentanediamine adipate, pentanediamine adipate and bio-based pentanediamine adipate were 208.0 °C, 182.3 °C and 182.9 °C, respectively. The polymerization of hexanediamine adipate, pentanediamine adipate and bio-based pentanediamine adipate happened at 201.0, 190.2 and 194.9 °C, respectively. And the decomposition temperature of PA66, PA56 and bio-based PA56 were 401.8, 403.5 and 405.2 °C, respectively.

Infrared spectra of the graft polymers of Capron fibre with tetrafluoroethylene

1978 ◽  
Vol 9 (4) ◽  
pp. 349-350
Author(s):  
Kh. U. Usmanov ◽  
A. A. Yul'chibaev ◽  
A. Valiev ◽  
P. P. Larin
Keyword(s):  
Infrared Spectra ◽  
Capron Fibre ◽  
Graft Polymers
Sign in / Sign up

Export Citation Format

Share Document