58. The use of thiophen as a chain extender. Part II. Synthetic branched-chain alkanoic acids

1962 ◽  
pp. 350 ◽  
Author(s):  
J. F. McGhie ◽  
W. A. Ross ◽  
D. Evans ◽  
J. E. Tomlin
Keyword(s):  
Chain Extender ◽  
Alkanoic Acids ◽  
Branched Chain ◽  
A Chain

scholarly journals On the explosion of chain-thermal reactions

1982 ◽  
Vol 24 (2) ◽  
pp. 194-202 ◽  
Author(s):  
R. O. Ayeni
Keyword(s):  
Activation Energy ◽  
Asymptotic Analysis ◽  
Upper Bound ◽  
Homogeneous Model ◽  
Chain Reaction ◽  
Isothermal Reaction ◽  
Thermal Reactions ◽  
Spatially Homogeneous ◽  
Branched Chain ◽  
A Chain

AbstractA chain reaction of oxygen (reactant) and hydrogen (active intermediary) with mtrosyl chloride (sensitizer) as a catalyst may be modelled mathematically as a non-isothermal reaction. In this paper we present an asymptotic analysis of a spatially homogeneous model of a non-isothermal branched-chain reaction. Of particular interest is the so-called explosion time and we provide an upper bound for it as a function of the activation energy which can vary over all positive values. We also establish a bound on the temperature when the activation energy is finite.

Effect of a chain extender on the properties of poly(lactic acid)/zinc oxide/copper chlorophyll acid antibacterial nanocomposites

2014 ◽  
pp. n/a-n/a ◽  
Author(s):  
Weihua Fan ◽  
Yue Zhao ◽  
Aijing Zhang ◽  
Yukun Liu ◽  
Yanxia Cao ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Lactic Acid ◽  
Chain Extender ◽  
Poly Lactic Acid ◽  
A Chain

scholarly journals Synthesis and Properties of Waterborne Polyurethane (WBPU)/Modified Lignin Amine (MLA) Adhesive: A Promising Adhesive Material

2016 ◽  
Author(s):  
Mohammad Mizanur Rahman ◽  
Md. Hasan Zahir ◽  
Han Do Kim
Keyword(s):  
Adhesive Strength ◽  
Weather Conditions ◽  
Waterborne Polyurethane ◽  
Chain Extender ◽  
Mixing Process ◽  
Adhesive Material ◽  
Lignin Amine ◽  
A Chain ◽  
Modified Lignin ◽  
Adhesive Materials

A series of waterborne polyurethane (WBPU)/modified lignin amine (MLA) adhesives was prepared using modified lignin amine (MLA) as a chain extender by a prepolymer mixing process. A successful Mannich reaction was achieved during the synthesis of MLA by reacting lignin with bis(3-aminopropyl)amine. Higher tensile strength, Young’s modulus and thermal stability were recorded for WBPU/MLA adhesives with higher MLA contents. The WBPU/MLA adhesive materials were used to coat PVC substrates. The adhesive strength increased with increasing MLA content. More importantly, the MLA also enhanced the WBPU/MLA coating in terms of adhesive strength at moderately high temperatures as well as under natural weather exposed conditions. The adhesive strength was essentially unaffected with 6.48 mole% MLA in the WBPU/MLA coating after exposure to natural weather conditions for 180 days.

Modification of nylon-6 with poly (m-phenylene isophthalamide) via MDI as a chain extender

1993 ◽  
Vol 28 (18) ◽  
pp. 4862-4867 ◽  
Author(s):  
Ming-Fung Lin ◽  
Yao-Chi Shu
Keyword(s):  
Nylon 6 ◽  
Chain Extender ◽  
A Chain

Rheology of Thermoplastic Polyurethanes

2007 ◽  
Author(s):  
Chang Dae Han
Keyword(s):  
Rheological Behavior ◽  
Thermoplastic Polyurethane ◽  
Complete Characterization ◽  
Chain Extender ◽  
Reaction Sequence ◽  
Molecular Weights ◽  
Soft Segments ◽  
Hard Segments ◽  
A Chain ◽  
Long Chain

Thermoplastic polyurethane (TPU) has received considerable attention from both the scientific and industrial communities (Hepburn 1982; Oertel 1985; Saunders and Frish 1962). Applications for TPUs include automotive exterior body panels, medical implants such as the artificial heart, membranes, ski boots, and flexible tubing. Figure 10.1 gives a schematic that shows the architecture of TPU, consisting of hard and soft segments. Hard segments, which form a crystalline phase at service temperature, are composed of diisocyanate and short-chain diols as a chain extender, while soft segments, which control low-temperature properties, are composed of difunctional long-chain polydiols with molecular weights ranging from 500 to 5000. The soft segments form a flexible matrix between the hard domains. TPUs are synthesized by reacting difunctional long-chain diol with diisocyanate to form a prepolymer, which is then extended by a chain extender via one of two routes: (1) by a dihydric glycol chain extender or (2) by a diamine chain extender. The most commonly used diisocyanate is 4,4’-diphenylmethane diisocyanate (MDI), which reacts with a difunctional polyol forming soft segments, such as poly(tetramethylene adipate) (PTMA) or poly(oxytetramethylene) (POTM), to produce TPU, in which 1,4-butanediol (BDO) is used as a chain extender. There are two methods widely used to produce TPU: (1) one-shot reaction sequence and (2) two-stage reaction sequence. The reaction sequences for both methods are well documented in the literature (Hepburn 1982). It should be mentioned that MDI/BDO/PTMA produces ester-based TPU. One can also produce ether-based TPU when MDI reacts with POTM using BDO as a chain extender. TPUs are often referred to as “multiblock copolymers.” In order to have a better understanding of the rheological behavior of TPUs, one must first understand the relationships between the chemical structure and the morphology; thus, a complete characterization of the materials must be conducted. The rheological behavior of TPU depends, among many factors, on (1) the composition of the soft and hard segments, (2) the lengths of the soft and hard segments and the sequence length distribution, (3) anomalous linkages (branching, cross-linking), and (4) molecular weight.

Synthesis and properties of a monolithic gradient polymer material based on polyurethane structures and 1,4-butanediol as a chain extender

2017 ◽  
Vol 59 (1) ◽  
pp. 12-26 ◽  
Author(s):  
E. S. Afanasyev ◽  
L. M. Goleneva ◽  
T. A. Matseevich ◽  
A. A. Askadskii
Keyword(s):  
Polymer Material ◽  
Chain Extender ◽  
A Chain

scholarly journals Chain extender effect of 3-(4-hydroxyphenyl)propionic acid/layered double hydroxide in biopolyesters containing the succinate moiety

2020 ◽  
Vol 44 (24) ◽  
pp. 10127-10136
Author(s):  
Laura Sisti ◽  
Grazia Totaro ◽  
Annamaria Celli ◽  
Adam A. Marek ◽  
Vincent Verney ◽  
...  
Keyword(s):  
Propionic Acid ◽  
Layered Double Hydroxide ◽  
Chain Extender ◽  
A Chain ◽  
Double Hydroxide

3-(4-Hydroxyphenyl)propionic acid intercalated in Mg2Al/layered double hydroxide has been used as a filler in biopolyesters containing the succinate moiety, with the aim of inducing a chain extender effect.

Mechanical recycling simulation of polylactide using a chain extender

2017 ◽  
Vol 37 (6) ◽  
pp. 2053-2060 ◽  
Author(s):  
Marina Fernandes Cosate de Andrade ◽  
Gustavo Fonseca ◽  
Ana Rita Morales ◽  
Lucia Helena Innocentini Mei
Keyword(s):  
Chain Extender ◽  
Mechanical Recycling ◽  
A Chain

scholarly journals Mechanical and Thermal Properties of Poly(urethane urea) Nanocomposites Prepared with Diamine-Modified Laponite

2008 ◽  
Vol 2008 ◽  
pp. 1-9 ◽  
Author(s):  
Joe-Lahai Sormana ◽  
Santanu Chattopadhyay ◽  
J. Carson Meredith
Keyword(s):  
Tensile Strength ◽  
Thermal Properties ◽  
Tensile Properties ◽  
Particle Concentration ◽  
Chain Extender ◽  
Mechanical And Thermal Properties ◽  
Elongation At Break ◽  
Hard Domain ◽  
A Chain

Nanocomposites based on segmented poly(urethane urea) were prepared by reacting a poly(diisocyanate) with diamine-modified Laponite-RD nanoparticles that served as a chain extender. The nanocomposites were prepared at a constantNH2to NCO mole ratio of 0.95, while varying the fraction of diamine-modified Laponite relative to the free diamine chain extender. Compared to neat poly(urethane urea), all nanocomposites showed increased tensile strength and elongation at break. As Laponite loading increased, tensile properties passed through a maximum at a particle concentration of 1 mass%, at which a 300% increase in tensile strength and 40% increase in elongation at break were observed. A maximum in urea and urethane hard-domain melting endotherms was also observed at this Laponite loading. Optimal mechanical and thermal properties coincided with a minimum in the size of the inorganic Laponite phase. Nanocomposites containing diamine-modified Laponite had higher tensile strengths than those with nonreactive monoamine-modified Laponite or diamine-modified Cloisite.

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