Amine Terminated Reactive Liquid Polymers; Modification of Thermoset Resins

1981 ◽  
Vol 54 (2) ◽  
pp. 374-402 ◽  
Author(s):  
C. K. Riew
Keyword(s):  
Molecular Weight ◽  
Elevated Temperatures ◽  
Average Molecular Weight ◽  
Impact Resistance ◽  
Secondary Amide ◽  
Amine Group ◽  
Low Viscosity ◽  
End Groups ◽  
Liquid Polymers ◽  
Reactive Liquid

Abstract Amine terminated reactive liquid polymers (AT-RLP) are synthesized from corresponding carboxyl terminated reactive liquid polymers (CT-RLP) and diamines. The CT-RLPs have a functionality of close to two, the average molecular weight ranging from 2500 to 4000, and Brookfield viscosity ranging from 30 to 600 Pa · s at 27°C. AT-RLPs made from the CT-RLPs have about the same physical properties as the CT-RLPs given above. N-(2-aminoethyl)piperazine (AEP2) is the best diamine among the diamines tried to produce low viscosity and low molecular weight AT-RLPs. Structure of end-groups of AT-RLP is unequivocally identified as a secondary amide and a secondary amine group resulting from the reaction of carboxyl end-groups of CT-RLP and a primary amine group of AEP,. The AT-RLP can be used as a modifier for epoxy resins at room or elevated temperatures to produce castable formulations with properties ranging from plastics to elastomers. The formulations may be useful as a modifier for improvement of crack and/or impact resistance of normally brittle epoxy plastics, as castable elastomers, paints and coatings, sealants, adhesives, especially as solventless adhesives for conveyor belts, hoses, shoes, and as binders for woven or non-woven fibers and cords.

scholarly journals Some Guidelines for the Synthesis and Melting Characterization of Azide Poly(ethylene glycol) Derivatives

Polymers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1269
Author(s):  
Daniel González-Fernández ◽  
Mercedes Torneiro ◽  
Massimo Lazzari
Keyword(s):  
Molecular Weight ◽  
Ethylene Glycol ◽  
Average Molecular Weight ◽  
Size Exclusion ◽  
Degree Of Crystallinity ◽  
Specific Class ◽  
Poly Ethylene Glycol ◽  
End Groups ◽  
Poly Ethylene

We provide fundamental guidelines in the form of a tutorial to be taken into account for the preparation and characterization of a specific class of poly(ethylene glycol) (PEG) derivatives, namely azide-terminated PEGs. Special attention is given to the effect of these chain end groups and their precursors on properties affecting the PEGylation of proteins, nanoparticles and nanostructured surfaces. Notwithstanding the presence of 13C satellite peaks, we show that 1H NMR enables not only the routine quantitative determination of chain-end substitution, but is also a unique method to calculate the absolute number average molecular weight of PEG derivatives. In the use of size exclusion chromatography to get molecular weight distributions, we highlight the importance of distinguishing between eventual secondary reactions involving molecular weight changes and the formation of PEG complexes due to residual amounts of metal cations from reactants. Finally, we show that azide end groups affect PEG melting behavior. In contrast to oxygen-containing end groups, azides do not interact with PEG segments, thus inducing defect formation in the crystal lattice and the reduction of crystal sizes. Melting temperature and degree of crystallinity decrease become especially relevant for PEGs with very low molecular weight, and its comprehension is particularly important for solid-state applications.

Effect of Molecular Weight (MW) and End-Groups on the Thermal and Lewis-Acid Catalyzed Decomposition of Fomblin Z-Type Lubricants

2005 ◽  
Author(s):  
Lei Li ◽  
Paul M. Jones ◽  
Alexei G. Merzlikine ◽  
Yiao-Tee Hsia
Keyword(s):  
Molecular Weight ◽  
Lewis Acid ◽  
Elevated Temperatures ◽  
Temperature Stability ◽  
Lewis Acid Site ◽  
High Temperature Stability ◽  
Disk Interface ◽  
End Groups ◽  
Acid Catalyzed ◽  
Fomblin Z

The high-temperature stability of disk lubricants has attracted a lot of interest in recent years because smaller head-media spacing may cause head-media contact and thus a local temperature rise. At elevated temperatures, the lubricant may either evaporate or decompose, leading to the eventual failure of the head-media interface. The decomposition might result from heating and/or may be catalyzed by the presence of a Lewis acid site at the head-disk interface (HDI). In this paper, we study how the chemical structure, namely, molecular weight (MW) and end-groups (see Fig. 1), of disk lubricants will affect the thermal and Lewis-acid catalyzed decomposition of the lubricant.

Ultrafast and Reversible Multiblock Formation by the SET-Nitroxide Radical Coupling Reaction

2010 ◽  
Vol 63 (8) ◽  
pp. 1227 ◽  
Author(s):  
Jakov Kulis ◽  
Craig A. Bell ◽  
Aaron S. Micallef ◽  
Michael J. Monteiro
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Elevated Temperatures ◽  
Click Reaction ◽  
Coupling Reaction ◽  
Nitroxide Radical ◽  
Self Healing ◽  
Exchange Reactions ◽  
Radical Coupling ◽  
End Groups

The single electron transfer-nitroxide radical coupling (SET-NRC) reaction has been used to produce multiblock polymers with high molecular weights in under 3 min at 50°C by coupling a difunctional telechelic polystyrene (Br-PSTY-Br) with a dinitroxide. The well known combination of dimethyl sulfoxide as solvent and Me6TREN as ligand facilitated the in situ disproportionation of CuIBr to the highly active nascent Cu0 species. This SET reaction allowed polymeric radicals to be rapidly formed from their corresponding halide end-groups. Trapping of these carbon-centred radicals at close to diffusion controlled rates by dinitroxides resulted in high-molecular-weight multiblock polymers. Our results showed that the disproportionation of CuI was critical in obtaining these ultrafast reactions, and confirmed that activation was primarily through Cu0. We took advantage of the reversibility of the NRC reaction at elevated temperatures to decouple the multiblock back to the original PSTY building block through capping the chain-ends with mono-functional nitroxides. These alkoxyamine end-groups were further exchanged with an alkyne mono-functional nitroxide (TEMPO–≡) and ‘clicked’ by a CuI-catalyzed azide/alkyne cycloaddition (CuAAC) reaction with N3–PSTY–N3 to reform the multiblocks. This final ‘click’ reaction, even after the consecutive decoupling and nitroxide-exchange reactions, still produced high-molecular-weight multiblocks efficiently. These SET-NRC reactions would have ideal applications in re-usable plastics and possibly as self-healing materials.

Polysulfide Polymers

1951 ◽  
Vol 24 (3) ◽  
pp. 709-723
Author(s):  
E. M. Fettes ◽  
J. S. Jorczak
Keyword(s):  
Molecular Weight ◽  
Stress Relaxation ◽  
Cross Linking ◽  
Condensation Polymerization ◽  
Solvent Resistance ◽  
Polymer Properties ◽  
End Groups ◽  
Different Types ◽  
Liquid Polymers ◽  
Polysulfide Polymers

Abstract The chemistry of the condensation polymerization is reviewed briefly. The structures of the polymeric products as well as the effects of copolymerization, cross-linking, end groups, and molecular weight upon polymer properties are discussed. The composition and properties of the commercial crude rubbers, water dispersions, and liquid polymers are presented together with ideas on the mechanism of their vulcanization. The reason for the odor of polysulfide polymers is discussed. Some information is presented on solvent resistance, stress relaxation, and other characteristics of the polymers. Applications for the different types of products are summarized.

scholarly journals The Choice of Recycling Methods for Single-Polymer Polyester Composites

2018 ◽  
Vol 55 (4) ◽  
pp. 658-665 ◽  
Author(s):  
Katarzyna Gawdzinska ◽  
Marcin Nabialek ◽  
Andrei Victor Sandu ◽  
Katarzyna Bryll
Keyword(s):  
Molecular Weight ◽  
Tensile Strength ◽  
Polymer Composites ◽  
Injection Moulding ◽  
Average Molecular Weight ◽  
Impact Resistance ◽  
Mass Fractions ◽  
Weight Impact ◽  
Polyester Composites ◽  
Work Done

This work has described the production of single-polymer composites by the film-stacking method. Two types of single-polymer composites with different mass fractions of the polyester reinforcement phase (10% and 20%) and the PETG matrix were investigated. The produced composites were subsequently recycled by injection moulding, pressing, and extrusion. Selected properties of the processed composites were determined: density, viscosity-average molecular weight, impact resistance, and tensile strength. The work done in this paper has demonstrated the benefits and drawbacks of each recycling method for these materials. The selected properties of single-polymer polyester composites and single-polymer polyester composites that were recycled by extrusion have also been compared.

Preparation, characterization, and antioxidant properties of polystyrenes with 4-methoxyphenol end groups

1983 ◽  
Vol 61 (1) ◽  
pp. 124-127 ◽  
Author(s):  
Brian K. Hunter ◽  
Kenneth E. Russell ◽  
Ataa K. Zaghloul
Keyword(s):  
Molecular Weight ◽  
Nuclear Overhauser Effect ◽  
Average Molecular Weight ◽  
Antioxidant Properties ◽  
Low Molecular Weight ◽  
Nmr Studies ◽  
Overhauser Effect ◽  
End Groups ◽  
Nuclear Overhauser ◽  
C Nmr

Polystyrenes with 4-methoxyphenol end groups have been prepared by the cationic polymerization of styrene in the presence of the phenol. The products range from 1:1 adduct to polymer of number-average molecular weight close to 3000. The 1:1 adduct separated from the reaction mixture was shown by nuclear Overhauser effect studies to be 2-(1-methylbenzyl)-4-methoxyphenol. Only about half of the polymer molecules have 4-methoxyphenol end groups. 13C nmr studies indicate that the polystyrene chains are attached principally at the 2-position of the phenol. The activity of the polymer as an antioxidant is comparable to that of corresponding low molecular weight methoxyphenols including butylated hydroxyanisole.

OLIGOMERIC GUANIDINE-CONTAINING PROTON CATIONIC IONIC LIQUID

2021 ◽  
Vol 43 (4) ◽  
pp. 304-310
Author(s):  
M.YA. VORTMAN ◽  
◽  
V.N. LEMESHKO ◽  
L.A. GONCHARENKO ◽  
S.M. KOBYLINSKIY ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Ionic Liquid ◽  
Ionic Liquids ◽  
Ionic Conductivity ◽  
Elevated Temperatures ◽  
Average Molecular Weight ◽  
Amorphous Structure ◽  
Aliphatic Chain ◽  
Minimum Surface Tension ◽  
Separation Of Gas Mixtures

Oligomeric ionic liquids occupy an intermediate position between low molecular weight and polymeric. They are promising as polymer electrolytes in electrochemical devices for various purposes, membranes for the separation of gas mixtures, in sensor technologies, and so on. Oligomeric guanidinium ionic liquids are practically not described in the literature. In terms of studying the effect of the structure of the epoxy component on the properties of oligomeric ionic liquids of this type, it is advisable to introduce into its composition an aliphatic oligoether component. The choice of aliphatic oligoepoxide for the synthesis of guanidinium oligomeric ionic liquids is based on the fact that it is structurally similar to poly - and oligoethylene oxides, which are known to be non-toxic, biodegradable, and reactive oligomeric ionic liquids at elevated temperatures. A new type of reactive oligomeric proton cationic ionic liquid was synthesized by the reaction of oligomeric aliphatic diepoxide with guanidine, followed by neutralization of the product with hydrochloric acid. In this study, the synthesis of proton cationic oligomeric ionic liquids was based on the introduction of guanidinium fragments as end groups of the oligoether aliphatic chain. This reaction is attractive because of the ease of opening the oxirane ring with such a strong nucleophile as guanidine.The reaction forms a fragment with an aliphatic C-N bond, which retains the high basicity of the nitrogen atom. Its structure is characterized by the presence of guanidinium groups at the ends of the aliphatic hydroxyl-containing oligoether chain. The chemical structure of this compound is characterized by IR -, 1H ,13 C NMR spectroscopy methods, and its molecular mass characteristics are determined.The average molecular weight of the synthesized oligomeric ionic liquids is 610 g / mol.The value of the coefficient of polydispersity of the synthesized oligomeric ionic liquids is equal to 1.2. Determination of the content of amino groups in the guanidine-containing oligomer in the basic form by titrometric method allowed to establish that the value found is close to the theoretically calculated value. The synthesized oligomeric proton ionic liquid is characterized by an amorphous structure with two glass transition temperatures. The first lies in the range -70 °C, the second in the region of 70 °C, and the beginning of thermal oxidative destruction is located in the region of 148 °C. The temperature dependence of the ionic conductivity for this compound is nonlinear in the Arrhenius coordinates, which indicates the realization of ionic conductivity mainly due to the free volume in the system. The proton conductivity of this compound is 6.4·10-5–1·10-2Cm/cmin the range of 20–100 °C. The obtained compound exhibits surface-active properties characteristic of classical surfactants, as evidenced by the value of the limiting surface activity – 2.8·102 Nm2 / kmol. The value of CCM is 1.8·10-2 mol/l., and the value of the minimum surface tension – 37.70 mN / m. The synthesized oligomeric ionic liquid is of interest as electrolytes operating under anhydrous conditions, surfactants, disinfectants, and starting reagents for the synthesis of ion-containing blockopolymers.

scholarly journals Effects of the Amount and Type of Diol Ring Openers on the Properties of Oligolactide Acrylates for UV-Curable Printing Inks

Coatings ◽  
2017 ◽  
Vol 7 (10) ◽  
pp. 174 ◽  
Author(s):  
Santi Kulsiriswad ◽  
Kawee Srikulkit ◽  
Onusa Saravari
Keyword(s):  
Molecular Weight ◽  
Chain Length ◽  
Alkyl Chain ◽  
Impact Resistance ◽  
Alkyl Chain Length ◽  
Proton Nuclear Magnetic Resonance ◽  
Resonance Spectroscopy ◽  
Uv Curable ◽  
Low Viscosity ◽  
Printing Inks

This study aimed to synthesize low viscosity oligolactide acrylates for UV-curable inks from oligolactide diols. Firstly, low molecular weight oligolactide diols were prepared by ring opening reaction of L-lactide with diols. Oligolactide acrylates were then synthesized by functionalizing the oligolactide diols with acrylic acid. In this study, three diol ring openers having short and long alkyl chain length were used to investigate the effects of the amount and type of diols on the properties of the oligolactide acrylates. The obtained oligomers were characterized, and the viscosities of oligolactide acrylates were measured. Results showed that oligolactide acrylates were successfully synthesized in all cases of ring openers, as confirmed by 1H-NMR (proton nuclear magnetic resonance spectroscopy) and FTIR (Fourier transform infrared spectroscopy). An increase in the alkyl chain length of the ring openers resulted in oligomers with lower viscosity and a decrease in Tg. Following that, the obtained oligolactide acrylates were employed for the formulation of UV-curable screen printing inks and their properties were investigated. Results showed that the inks formulated from oligomers with lower molecular weight exhibited better ink flow. Additionally, all ink films cured by UV radiation were very flexible with excellent adhesion, high impact resistance, and excellent water resistance.

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