One-Component Urethane Sealants Synthesis

2020 ◽  
Vol 869 ◽  
pp. 152-157
Author(s):  
Irina V. Zhukova ◽  
Aleksandr A. Tabachkov ◽  
Svetlana N. Ivanova ◽  
Ilnar A. Valeev
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Methyl Iodide ◽  
Physical And Mechanical Properties ◽  
Imine Group ◽  
Cure Time ◽  
Activating Agent ◽  
Crosslinking Agents

It is proposed to synthesize one-component light-resistant urethane compositions using aldimines as crosslinking agents and methyl iodide as an activating agent to obtain sealants. The effect of the methyl iodide activator and the quaternized complex of the imine group and temperature on the cure time of the sealants was investigated. The influence of the polyether molecular weight and the structure of aldimines fillers on the physical and mechanical properties of the obtained sealants was studied.

PEG Molecular Weight Effects on Physical and Mechanical Properties of ETICS Plaster, Hardening at Lowered Positive and Small Negative Temperatures

2014 ◽  
Vol 1004-1005 ◽  
pp. 1482-1485 ◽  
Author(s):  
Stanislav Pashkevich ◽  
Andrey Pustovgar ◽  
Aleksey Eremin ◽  
Aleksey Adamtsevich ◽  
Sergey Nefedov
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Compressive Strength ◽  
Polyethylene Glycol ◽  
Physical And Mechanical Properties ◽  
Negative Temperature ◽  
Polystyrene Foam ◽  
Molecular Weights ◽  
Negative Temperatures

The paper presents the influence of polyethylene glycol additives wit h molecular weights of 2000... 6000 on basic physical and mechanical properties of plaster hardening at low positive and negative temperature s . The dependence of adhesion s trength to the polystyrene foam as well as compressive strength of plaster hardening at tempe rature s (+5... -10) oC on PEG molecular weight was established.

High Molecular Weight Polyethylene Nanospheres: Synthesis, Physical and Mechanical Properties—Second Harmonic Generation

2008 ◽  
Vol 8 (6) ◽  
pp. 2979-2982
Author(s):  
C. J. Hsu ◽  
L. W. Chang ◽  
S. Y. Miao ◽  
J. T. Lue
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Molecular Weight ◽  
Harmonic Generation ◽  
Signal Intensity ◽  
Second Harmonic ◽  
Physical And Mechanical Properties ◽  
Graphene Sheets ◽  
Multi Wall Carbon Nanotubes ◽  
Anharmonic Oscillation

The weak second harmonic light generating from carbon nanotubes are detected. The signal intensity closely related to the density of π-bonds attributed to the defects in the rolled graphene sheets, which is stimulated to have anharmonic oscillation as strongly affected by the environment. The intensities of SHG are diminished in order of well-aligned multi-wall carbon nanotubes (MWCNTs), randomly-aligned MWCNTs, and then to single-wall CNTs.

scholarly journals INVESTIGATION OF IMPACT OF CROSSLINKING AGENTS ON CHARACTERISTICS OF SPATIAL NET AND PROPERTIES OF STYRENE-ACRYLIC POLYMER FILMS

2018 ◽  
Vol 61 (7) ◽  
pp. 68
Author(s):  
Inna Slepchuk ◽  
Olga Ya. Semeshko ◽  
Tatiana S. Asaulyuk ◽  
Yuliya G. Saribekova
Keyword(s):  
Mechanical Properties ◽  
Polymer Film ◽  
Polymer Films ◽  
Crosslinking Agent ◽  
Hydrolytic Degradation ◽  
Physical And Mechanical Properties ◽  
Acrylic Polymer ◽  
The Individual ◽  
High Degree ◽  
Crosslinking Agents

The influence of crosslinking agents on the characteristics and properties of films from aqueous dispersions of styrene-acrylic polymers Lacritex 309, 430 and 640 was studied in order to obtain coatings on textile materials. Mono-, di- and triglycidyl esters are chosen as crosslinking agents. The choice of aqueous dispersions of polymers and crosslinkers is due to strict environmental requirements for textile products. By determining the amount of aceton-insoluble fractions of the formed polymer films, it was determined that the incorporation of crosslinkers is required in the Lacritex dispersion 640, and the films based on Lacritex 430 and 309 are distinguished by a high degree of intermolecular crosslinking. Optimum concentrations of crosslinkers have been established, which provide a high degree of curing of Lacritex 640. Using the sol-gel method, the structural parameters of the spatial nets of styrene-acrylic polymers (the part of sol fraction, the degree of crosslinking, the part of active chains, the average molecular weight of the chain segment, the crosslink density) were calculated. The polymer films from the individual polymer Lacritex 430 have the highest indexes of physic mechanical characteristics. Lacritex 640/Laproxide 703 compositions can be used as polymer matrixes for textile materials. The formation of crosslinks of hydroxyl and carboxyl groups of the styrene-acrylic polymer with epoxy groups of the crosslinking agent was confirmed by IR spectroscopy. The investigation of the effect of water and soap-soda treatments at various temperatures shows that the films under study have high resistance to water and soap-soda solution. The results of investigation of the tensile strength, the elongation at break, the hardness of the coating surface by the Koenig method and the stickiness according to the FINAT method (Test Method Number 9) of the formed polymer films indicate high physical and mechanical properties such as increased mechanical strength and elasticity, reduced hardness and tackiness. Thus, based on the studies carried out, it can be concluded that the individual styrene-acrylic Lacritex polymers 309 and 430 provide the formation of a strong three-dimensional spatial structure of the polymer film and can be used without crosslinking agents. The use of Lacritex 640 is possible in the composition together with the Laproxide 703 crosslinking agent at an optimum concentration of 4%. A polymer film based on this composition has a high degree of crosslinking, and as a result, increased resistance to organic solvents, reduced hydrolytic degradation at high temperatures, and increased physico-mechanical properties. A polymer film based on this composition has a high degree of crosslinking, hence, has increased resistance to organic solvents, reduced hydrolytic degradation at high temperatures, and increased physical and mechanical properties. Forcitation:Slepchuk I., Semeshko O.Ya., Asaulyuk T.S., Saribekova Yu.G. Investigation of impact of rosslinking agents on characteristics of spatial net and properties of styrene-acrylic polymer films. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 7. P. 67-75

scholarly journals Effect of environmental conditions on the durability of polycarbonate for the protection of cultural heritage sites

2019 ◽  
Vol 17 (4) ◽  
pp. 228080001988162
Author(s):  
Laura Ascione ◽  
Maria Chiara Mistretta ◽  
MariaPia Pedeferri ◽  
Francesco Paolo La Mantia
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Cultural Heritage ◽  
Physical And Mechanical Properties ◽  
Oxidation Reactions ◽  
Yellowness Index ◽  
Photo Oxidation ◽  
Heritage Sites ◽  
Degradation Temperature ◽  
Moisture Conditions

Polycarbonate is a good material for covering and protecting cultural heritage sites because of its durability, mechanical properties, and transparency. However, polycarbonate degrades under environmental weathering with a significant decrease of physical and mechanical properties and loss of transparency. In this work, the contemporary presence of ultraviolet irradiation and different temperature and moisture conditions have been taken into account to study the environmental degradation of this polymer with regard to its mechanical and optical properties. The photo-oxidation reactions cause a decrease in the molecular weight and the formation of many oxygenated species. The hydrolytic scission, instead, gives rise to a remarkable reduction in the molecular weight. These two different degradation mechanisms do not seem interconnected because at the lowest degradation temperature and high humidity levels, the reduction of the molecular weight is more pronounced than that observed at the highest temperature but at a lower humidity level. Transparency decreases with the degradative processes, but even after severe degradation the loss of transparency is only about 10%. The yellowness index increases during the first stages of degradation, which has been attributed to the fast formation of carbonyl groups due to photo-oxidation.

Polyamide 6 and high molecular weight phenol novolac blend having excellent mechanical properties in humid conditions

2018 ◽  
Vol 32 (6) ◽  
pp. 778-794 ◽  
Author(s):  
Takayuki Hirai ◽  
Kenzo Fukumori ◽  
Taiji Ikawa ◽  
Tetsuya Oda
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Glass Transition ◽  
High Molecular Weight ◽  
Room Temperature ◽  
Glassy State ◽  
Physical And Mechanical Properties ◽  
Polyamide 6 ◽  
Low Molecular Weight ◽  
Melt Mixing

Polymer blends of polyamide 6 (PA6) and phenol novolac (PN) were prepared by melt mixing. Up to 30 wt% of high molecular weight PN (HPN) or low molecular weight PN (LPN) was blended with PA6, and the physical and mechanical properties were examined. The water absorption of PA6 is inhibited by PN, and this effect is independent of the molecular weight of PN. PA6 and PN are miscible, and their blends show a single glass transition temperature ( T g) that is higher than that of PA6. HPN can enhance the T g of PA6 more efficiently than LPN because of its high T g. PA6 and the PA6/LPN blend after immersion in water had lower-than-room-temperature T gs transitioning to rubbery states. In contrast, the PA6/HPN blend after immersion in water had a higher-than-room-temperature T g. The PA6/HPN blend in water has excellent mechanical properties in its glassy state compared to those of PA6 in the dry state. Thus, the PA6/HPN blend can be used to broaden the applications of PA6, especially in humid conditions.

Blown Film of m-LLDPE Using a Novel Eccentric Rotor Extruder

2018 ◽  
Vol 783 ◽  
pp. 28-33
Author(s):  
He Zhi He ◽  
Shi Ming Liu ◽  
Lan Ya Cheng ◽  
Yi Ping Ni ◽  
Feng Xue ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Physical And Mechanical Properties ◽  
Elongational Flow ◽  
Screw Extruder ◽  
Novel Device ◽  
Single Screw ◽  
Single Screw Extruder ◽  
Eccentric Rotor ◽  
The One

Metallocene linear low-density polyethylene (m-LLDPE) has superior physical and mechanical properties. While, the film blowing processability of m-LLDPE was very poor when processed under shear flow. To overcome this drawback, a novel device based on elongational flow was self-developed to process m-LLDPE. In order to investigate the effect of elongational flow on the processability improvement of m-LLDPE, five types PE were studied in this paper. All kinds of PE were prepared using this novel device and traditional single-screw extruder with molecular weight and its distribution, mechanical properties and WAXD characterization. Gel Pemeation Chromotographer (GPC) data shows that molecular weight of each resin prepared using this novel eccentric rotor extruder (ERE) is higher than that processed by traditional single screw extruder (SSE). Mechanical properties showed that tensile properties of all kinds of films blowing from ERE is better than the one from SSE. However, tear properties of m-LLDPE films made from ERE differ from LDPE or LLDPE. And had a relative low value than the one made from SSE. In addition, Wide-angle X-ray Diffraction (WAXD) results indicate that films blowing from ERE exist a partially ordered component in addition to the usual crystalline and amorphous components which can’t be achieved from SSE.

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