Long chain alkanesulfonates and 1-hydroxy-2-alkanesulfonates: Structure and property relations

1963 ◽  
Vol 40 (10) ◽  
pp. 538-541 ◽  
Author(s):  
J. K. Weil ◽  
F. D. Smith ◽  
A. J. Stirton ◽  
R. G. Bistline
Keyword(s):  
Structure And Property ◽  
Property Relations ◽  
Long Chain

Structure and property relations between the polyacrylonitrile-based prestabilized fibers and the partially carbonized fibers

2011 ◽  
pp. n/a-n/a
Author(s):  
Meijie Yu ◽  
Yong Xu ◽  
Chengguo Wang ◽  
Bo Zhu ◽  
Yanxiang Wang ◽  
...  
Keyword(s):  
Structure And Property ◽  
Property Relations

Synthesis and properties of low coefficient of thermal expansion copolyimides derived from biphenyltetracarboxylic dianhydride with p-phenylenediamine and 4,4′-oxydialinine

e-Polymers ◽  
2016 ◽  
Vol 16 (4) ◽  
pp. 295-302 ◽  
Author(s):  
Yonglin Lei ◽  
Yuanjie Shu ◽  
Jinhua Peng ◽  
Yongjian Tang ◽  
Jichuan Huo
Keyword(s):  
Thermal Stability ◽  
Thermal Expansion ◽  
Coefficient Of Thermal Expansion ◽  
Thermomechanical Analysis ◽  
Amic Acid ◽  
Molar Ratio ◽  
Structure And Property ◽  
Property Relations ◽  
Ft Ir ◽  
Biphenyltetracarboxylic Dianhydride

AbstractA series of copolyimides were prepared by thermal imidization of poly(amic acid)s (PAAs) derived from 3,3′,4,4′-biphenyltetracarboxylic dianhydride (s-BPDA), 2,3′,3,4′-biphenyltetracarboxylic dianhydride (a-BPDA), p-phenylenediamine (PDA) and 4,4′-oxydialinine (4,4′-ODA) commonly used for the production of commercial polyimides. The flexible copolyimide films were obtained from that the molar ratio of s-BPDA, a-BPDA, PDA and 4,4′-ODA was 9:1:8:2 (Co-PIs-3), 8:2:9:1 (Co-PIs-5) and 8:2:8:2 (Co-PIs-6). These obtained copolyimide films were characterized by Fourier transform-infrared spectroscopy(FT-IR), wide angle X-ray (WAXD), Thermogravimetric (TG), dynamic mechanical thermal analysis (DMA), thermomechanical analysis (TMA), field-emission scanning electron microscopy (FE-SEM) and mechanical properties measurement. The results showed that three copolyimides remained semi-crystalline and exhibited high glass transition temperature (Tg), high thermal stability, great ultimate tensile strength and low coefficient of thermal expansion (CTE). The Co-PIs-5 had lower crystallinity, lower CTE, greater elongation at break, higher Tg and thermal stability and the greater dense extent, compared with Co-PIs-3 and Co-PIs-6. Structure and property relations of the prepared polyimides were also briefly discussed. The results revealed that the copolymerization of s-BPDA/PDA with a small number of 4,4′-ODA/a-BPDA was a useful means for enhancing flexibility without sacrificing low CTE.

Study on structure and property relations of α-iPP during uniaxial deformation via in situ synchrotron SAXS/WAXS and POM investigations

2017 ◽  
Vol 58 (2) ◽  
pp. 160-169
Author(s):  
Yingrui Shang ◽  
Puqing Ning ◽  
Yao Zhang ◽  
Feifei Xue ◽  
Ziwei Cai ◽  
...  
Keyword(s):  
Uniaxial Deformation ◽  
Structure And Property ◽  
Property Relations ◽  
Synchrotron Saxs

Synthesis of Cellulose Long-Chain Esters in 1-Butyl-3-methylimidazolium Acetate: Structure-Property Relations

2018 ◽  
Vol 60 (3) ◽  
pp. 349-353 ◽  
Author(s):  
Shuang Men ◽  
Xinyang Jiang ◽  
Xiaotong Xiang ◽  
Guoxin Sun ◽  
Yahong Yan ◽  
...  
Keyword(s):  
Structure Property ◽  
Property Relations ◽  
Long Chain

Bulk Semicrystalline Polymers: A Status Report

1993 ◽  
Vol 321 ◽  
Author(s):  
H. D. Keith
Keyword(s):  
Crystallization Process ◽  
Polymeric Materials ◽  
Basic Research ◽  
Semicrystalline Polymers ◽  
Status Report ◽  
Structure Property ◽  
Chain Molecules ◽  
Property Relations ◽  
Technological Significance ◽  
Long Chain

ABSTRACTDiscovery several decades ago that long-chain molecules crystallize by folding prompted vigorous basic research on structure-property relations in bulk semicrystalline polymers with expectation of insights that, paralleling experience in metal physics, would lead to better materials for technology. However, complexity of the crystallization process and difficulty in exploring morphology in adequate detail were both underestimated. Important aspects of behavior were recognized but improved polymeric materials have resulted more from exploratory engineering with composites and blends than from basic research on homopolymers. A summary of this research is presented with emphasis upon developments key to present status; also upon the truly formidable challenges that remain, Most readily accessible questions for research being of limited technological significance.

scholarly journals Structure and Property of Microinjection Molded Poly(lactic acid) with High Degree of Long Chain Branching

2018 ◽  
Vol 57 (33) ◽  
pp. 11312-11322 ◽  
Author(s):  
Zhong-Guo Zhao ◽  
Qi Yang ◽  
Phil Coates ◽  
Ben Whiteside ◽  
Adrian Kelly ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Poly Lactic Acid ◽  
Chain Branching ◽  
Long Chain Branching ◽  
Structure And Property ◽  
High Degree ◽  
Long Chain

Polymer Morphology Revealed by Staining Techniques

1981 ◽  
Vol 39 ◽  
pp. 340-341
Author(s):  
A. C. Reimschuessel ◽  
V. Kramer
Keyword(s):  
Polymer Melt ◽  
Nylon 6 ◽  
Morphological Features ◽  
Negative Staining ◽  
Polymer Morphology ◽  
Crystallizable Polymer ◽  
Staining Techniques ◽  
Long Chain

Staining techniques can be used for either the identification of different polymers or for the differentiation of specific morphological domains within a given polymer. To reveal morphological features in nylon 6, we choose a technique based upon diffusion of the staining agent into accessible regions of the polymer.When a crystallizable polymer - such as nylon 6 - is cooled from the melt, lamellae form by chainfolding of the crystallizing long chain macromolecules. The regions between adjacent lamellae represent the less ordered amorphous domains into which stain can diffuse. In this process the lamellae will be “outlined” by the dense stain, giving rise to contrast comparable to that obtained by “negative” staining techniques.If the cooling of the polymer melt proceeds relatively slowly - as in molding operations - the lamellae are usually arranged in a radial manner. This morphology is referred to as spherulitic.

A theory of contamination in electron microscopes by surface diffusion

1978 ◽  
Vol 36 (1) ◽  
pp. 116-117
Author(s):  
J.T. Fourie
Keyword(s):  
Electron Beam ◽  
Surface Diffusion ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Physical Parameters ◽  
Carbon Compounds ◽  
Hydrocarbon Molecules ◽  
Electron Microscopes ◽  
Primary Electrons ◽  
Long Chain

Contamination in electron microscopes can be a serious problem in STEM or in situations where a number of high resolution micrographs are required of the same area in TEM. In modern instruments the environment around the specimen can be made free of the hydrocarbon molecules, which are responsible for contamination, by means of either ultra-high vacuum or cryo-pumping techniques. However, these techniques are not effective against hydrocarbon molecules adsorbed on the specimen surface before or during its introduction into the microscope. The present paper is concerned with a theory of how certain physical parameters can influence the surface diffusion of these adsorbed molecules into the electron beam where they are deposited in the form of long chain carbon compounds by interaction with the primary electrons.

The effects of low-ratio n-6/n-3 PUFA on biomarkers of inflammation: a systematic review and meta-analysis

2021 ◽  
Author(s):  
Yali Wei ◽  
Yan Meng ◽  
Na Li ◽  
Qian Wang ◽  
Liyong Chen
Keyword(s):  
Systematic Review ◽  
Fatty Acid ◽  
Polyunsaturated Fatty Acid ◽  
Meta Analysis ◽  
Chain Polyunsaturated Fatty Acid ◽  
Inflammation Markers ◽  
Pufa Supplementation ◽  
Long Chain

The purpose of the systematic review and meta-analysis was to determine if low-ratio n-6/n-3 long-chain polyunsaturated fatty acid (PUFA) supplementation affects serum inflammation markers based on current studies.

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