scholarly journals ВПЛИВ ХІМІЧНОЇ БУДОВИ ЗШИВАЮЧИХ АГЕНТІВ НА ФІЗИЧНІ ВЛАСТИВОСТІ ПОЛІМЕРНИХ ПЛІВОК НА ОСНОВІ КРОХМАЛЮ

Author(s):  
Т. С. Асаулюк ◽  
О. Я. Семешко ◽  
Ю. Г. Сарібєкова

To study the effect of active functional groups of cross-linking agents on the physical properties of starch polymer films. Standardized methods for studying the indicators of physical properties of polymer films have been applied. The paper presents the results of the study of the effect of crosslinking agents of different chemical structure on the physicomechanical properties, the influence of atmospheric moisture and the resistance to wet treatments of starch polymer films. An improvement in studied parameters of the films with the use of L-tartaric acid was established. It has been proved that the use of L-tartaric acid as a crosslinking agent makes it possible to improve the physical properties of polymer films based on starch. The obtained experimental results are of practical importance for the development of new environmentally friendly polymer materials.

Author(s):  
Imana Shahrin Tania ◽  
Md. Zulhash Uddin ◽  
Kawser Parveen Chowdhury

TApplication of crosslinking agent to impart wrinkle recovery property on cotton fabrics is very popular for textile industry. This paper represents the effect of different crosslinking agent on the physical properties and the wrinkle recovery of cotton knit fabric. Here five different types of crosslinking agent from three different chemical companies were used. The work was divided into two parts .At first; crosslinking agents were applied on cotton fabric than various related tests were done on the treated and untreated fabric. Better crease resistancy was found on the finishing agent having high formaldehyde content .The other important properties like tensile strength, dimensional stability, stiffness, abrasion resistance pilling resistance and areal density was studied here. Among them some properties were improved and some were fall down.


1980 ◽  
Vol 53 (3) ◽  
pp. 393-436 ◽  
Author(s):  
E. Morita

Abstract Since the discovery by Goodyear in 1839 that the physical properties of rubber may be improved with sulfur, it has been the most commonly used crosslinking agent. The rubber industry is concerned with the production of homogeneous products with appropriate physical properties, by compounding rubber with ingredients, including crosslinking agents, followed by processing, molding, and introduction of chemical bonds. Economically, it is advantageous to apply high temperature which reduces processing and curing time. However, application of high temperatures frequently causes premature cure. Compounding adjustments are often required in the plants to prevent scorch, especially by the use of compounds with S—N bonds as accelerators, vulcanizing agents, and also as prevulcanization inhibitors or retarders which delay the crosslinking reaction of sulfur and rubber. There are several reviews relating to accelerators, retarders, and vulcanization, which discuss S—N compounds as delayed action curing agents. This review covers the development of S—N compounds as delayed action chemicals for vulcanizing rubber, the various structural types, properties, applications, and the mechanism of their function during vulcanization.


Author(s):  
Inna Slepchuk ◽  
Olga Ya. Semeshko ◽  
Tatiana S. Asaulyuk ◽  
Yuliya G. Saribekova

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


2021 ◽  
Author(s):  
Madhvi Garg ◽  
Navneet Bhullar ◽  
Bharat Bajaj ◽  
Dhiraj Sud

The present manuscript reports the ultrasound radiation induced synthesis of grafted chitosan hydrogels (CAAT and CAAG) using terephthalaldehyde/glutaraldehyde as crosslinking agents and its application for removal of synthetic dyes from...


Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1388
Author(s):  
Kathryn E. O’Harra ◽  
Emily M. DeVriese ◽  
Erika M. Turflinger ◽  
Danielle M. Noll ◽  
Jason E. Bara

This work introduces a series of vinyl-imidazolium-based polyelectrolyte composites, which were structurally modified via impregnation with multivalent imidazolium-benzene ionic liquids (ILs) or crosslinked with novel cationic crosslinkers which possess internal imidazolium cations and vinylimidazolium cations at the periphery. A set of eight [C4vim][Tf2N]-based membranes were prepared via UV-initiated free radical polymerization, including four composites containing di-, tri-, tetra-, and hexa-imidazolium benzene ILs and four crosslinked derivatives which utilized tri- and tetra- vinylimidazolium benzene crosslinking agents. Structural and functional characterizations were performed, and pure gas permeation data were collected to better understand the effects of “free” ILs dispersed in the polymeric matrix versus integrated ionic crosslinks on the transport behaviors of these thin films. These imidazolium PIL:IL composites exhibited moderately high CO2 permeabilities (~20–40 Barrer), a 4–7× increase relative to corresponding neat PIL, with excellent selectivities against N2 or CH4. The addition of imidazolium-benzene fillers with increased imidazolium content were shown to correspondingly enhance CO2 solubility (di- < tri- < tetra- < hexa-), with the [C4vim][Tf2N]: [Hexa(Im+)Benz ][Tf2N] composite showing the highest CO2 permeability (PCO2 = 38.4 Barrer), while maintaining modest selectivities (αCO2/CH4 = 20.2, αCO2/N2 = 23.6). Additionally, these metrics were similarly improved with the integration of more ionic content bonded to the polymeric matrix; increased PCO2 with increased wt% of the tri- and tetra-vinylimidazolium benzene crosslinking agent was observed. This study demonstrates the intriguing interactions and effects of ionic additives or crosslinkers within a PIL matrix, revealing the potential for the tuning of the properties and transport behaviors of ionic polymers using ionic liquid-inspired small molecules.


2003 ◽  
Vol 21 (5) ◽  
pp. 439-449 ◽  
Author(s):  
Yoshiaki Shimizu ◽  
Atsushi Taga ◽  
Hitoshi Yamaoka

Novel chitosan-based adsorbent materials with a higher fatty diacid diglycidyl as the crosslinking agent were synthesized and the adsorption abilities of the resulting polymers evaluated towards typical acid dyes. The successful formation of a crosslinked structure was confirmed via infrared spectroscopic measurements and the solubility of the polymer towards 10% aqueous solutions of acetic and formic acids determined. At higher dye concentrations, the adsorption abilities of the crosslinked chitosan towards hydrophilic CI Acid Orange 7 and CI Acid Red 1 increased with decreasing degree of substitution. However, at lower dye concentrations, the crosslinked chitosan with the lowest degree of substitution exhibited the lowest adsorption capability. With such hydrophilic acid dyes, the extent of adsorption decreased significantly as the pH of the solution increased. On the other hand, CI Acid Red 138, which contains a dodecyl group in the chemical structure, was adsorbed to a considerable extent even at higher pH values, suggesting hydrophobic interaction between the alkyl group in the dye molecule and the hydrophobic crosslinker.


1964 ◽  
Vol 16 (11) ◽  
pp. 345-351 ◽  
Author(s):  
Edna M. Montgomery ◽  
K. R. Sexson ◽  
R. J. Dimler ◽  
F. R. Senti

2007 ◽  
Vol 21 (1) ◽  
pp. 29-34 ◽  
Author(s):  
Cláudio Maniglia-Ferreira ◽  
Eduardo Diogo Gurgel-Filho ◽  
João Batista Araújo Silva Jr ◽  
Regina Célia Monteiro de Paula ◽  
Judith Pessoa Andrade Feitosa ◽  
...  

This study was undertaken to explore the effect of heating on gutta-percha, analyzing the occurrence of endothermic peaks corresponding to the transformation that occurs in the crystalline structure of the polymer during thermal manipulation. This study also seeked to determine the temperature at which these peaks occur, causing a transformation from the beta- to the alpha-form, and from the alpha- to the amorphous phase. Eight nonstandardized gutta-percha points commercially available in Brazil (Konne, Tanari, Endopoint, Odous, Dentsply 0.04, Dentsply 0.06, Dentsply TP, Dentsply FM) and pure gutta-percha (control) were analysed using differential scanning calorimetry (DSC) and thermogravimetry analysis (TGA). The transition temperatures were determined and analysed. With the exception of Dentsply 0.04 and Dentsply 0.06, the majority of the products showed thermal behaviour typical of beta-gutta-percha, with two endothermic peaks, exhibiting two crystalline transformations upon heating from ambient temperature to 130°. Upon cooling and reheating, few samples presented two endothermic peaks. It was concluded that heating dental gutta-percha to 130°C causes changes to its chemical structure which permanently alter its physical properties.


1969 ◽  
Vol 42 (3) ◽  
pp. 924-935 ◽  
Author(s):  
T. Colclough ◽  
J. I. Cunneen ◽  
G. M. C. Hrggins

Abstract A natural rubber vulcanizate containing almost entirely monosulfidic crosslinks was oxidized in oxygen and with tert-butyl hydroperoxide. The changes in physical properties due to oxidation were followed by stress—strain measurements, and the changes in chemical structure were investigated with chemical probes, and by spectroscopic methods. The results show that when the oxidized vulcanizates are heated at 75° C, the monosulfidic crosslinks are broken, that crosslinks containing two sulfur atoms are formed, and that conjugated diene and triene structures are introduced into the main polyisoprene chains.


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