Modifiers for Rigid Polyvinylchloride Compositions of Building Purpose

2020 ◽  
Vol 787 (12) ◽  
pp. 34-39
Author(s):  
L.A. Abdrakhmanova ◽  
◽  
K.R. Khuziakhmetova ◽  
R.K. Nizamov ◽  
V.G. Khozin ◽  
...  

A comparison of small doses (up to 0.7 mass part) of impact strength modifiers of foreign and domestic production in polyvinylchloride-based compositions is given. Domestic acrylicnitrile- butadiene styrene modifiers (ABS) were used. The developed shock-resistant polyvinylchloride compositions in the presence of ABS elastifier have high melt fluidity, which has a beneficial effect on the recyclability. Changes in supramolecular structure were estimated from thermomechanical testing and electron microscopy data for both unfilled and filled PVC samples. Thermomechanical analysis showed that the presence of ABS modifier had a favorable effect on the technological properties of PVC-based samples. Electron-microscopic images indicate that in unfilled PVC samples, the heterogeneous PVC structure is expressed in the presence of ABS copolymer in comparison with foreign acrylic modifiers. When the compositions are filled with micro-heterogeneous structure in dispersion medium, the filler-polymer is formed by chalk particles, while ABS elasticifier is at the phase interface. Due to the peculiarities of the structure ABS has a higher degree of “fixation” on the surface of the chalk particles in comparison with the basic compositions containing acrylic modifiers, which with increasing chalk concentration leads to lower wear and tear on the top of the forming equipment.

2016 ◽  
Vol 49 (3) ◽  
pp. 209-225 ◽  
Author(s):  
Mohamad Al Hafiz Ibrahim ◽  
Azman Hassan ◽  
Mat Uzir Wahit ◽  
Mahbub Hasan ◽  
Munirah Mokhtar

Polypropylene (PP)/poly(acrylonitrile–butadiene–styrene) (ABS) blends containing montmorillonite (MMT) compatibilized with polypropylene-grafted maleic anhydride were prepared by melt extrusion using twin screw extruder followed by injection molding. Mechanical properties were evaluated through tensile, flexural, and impact testing. The microstructure and formation of nanocomposites were assessed by scanning and transmission electron microscopy and X-ray diffraction (XRD). Incorporation of polypropylene-grafted maleic anhydride and MMT into PP/ABS blend led to higher strength and stiffness but at the expense of toughness. Scanning electron micrographs revealed a fine and homogeneous dispersion of ABS phase in PP matrix. Both XRD and transmission electron microscopic analysis revealed the formation of intercalated clay silicate layer in PP/ABS nanocomposites.


2019 ◽  
Vol 23 (11) ◽  
pp. 60-65
Author(s):  
S.V. Leontev ◽  
V.A. Shamanov ◽  
A.D. Kurzanov

The results of studying the structure formation features of silicate bricks obtained with the use of solid waste produced by JSC "Berezniki soda plant" are presented in this article. Various samples, such as sludge from the "closed" sump with a moisture content of 5 %, sludge from the open sump surface with a moisture content of 35 %, moistened sludge from the open sump with a moisture content of 70 %, were taken from the sludge collectors for the research. It was established the building lime meeting the requirements of GOST 9179 can be received by means of heat treatment at 950 °C of the dehydrated slime selected from the closed settler. By results of silicate brick samples forming parameters and their structure optimization it was found that the use of lime from soda production solid waste as part of lime-silica autoclave hardening binder allows to obtain silicate bricks samples, characterized by the strength grade M200. Samples microstructure studies obtained using the methods of electron microscopic and x-ray phase analysis showed that silicate samples produced with the use of soda production waste are characterized by a cementing substance heterogeneous structure and an insufficient number of tobermorite group low-basic calcium hydrosilicates formed during autoclaving. This is due to the waste material composition, namely the presence of reactive-passive components and impurities. Increasing the structural strength of samples made with the use of soda production wastes is possible due to raising the lime-silica binder specific surface area and the binder modification with fine mineral additives.


2016 ◽  
Vol 29 (1) ◽  
pp. 36-45 ◽  
Author(s):  
Rui Li ◽  
Cheng Zhou ◽  
Yang Chen ◽  
Huawei Zou ◽  
Mei Liang ◽  
...  

In this work, a series of silicone-containing epoxy copolymers (E231) were synthesized through a condensation reaction between the Si-OCH3 of SY231 and the –OH of E51. The chemical structural determinations of the copolymer were carried out with the Fourier transform infrared spectroscopy, nuclear magnetic resonance (NMR), and an epoxy equivalent weight test. Besides, the grafting content of SY231 in E231 copolymers was determined by the proton (1H) NMR integration technique. The mechanical properties, thermal stabilities, and morphology of impact fractured surface of cured products were also investigated. The experimental results show that increased impact strength was observed for the cured E231 products, meanwhile the improvement of the impact strength was closely related to the content of silicone in copolymers. A smooth surface was observed on the neat epoxy specimen, while a rough surface was observed by scanning electron microscopic examination on the impact fractured surface of the cured E231 products. The data of TGA indicated that silicone exerted its thermal stability through thermal decomposition energy dissipation, acted as thermal insulation, and finally enhanced the solid residue at 800°C. Dynamic thermomechanical analysis tests displayed that the glass transition temperature of epoxy systems decreased slightly with the introduction of the flexible organosilicone.


Author(s):  
R. A. Waugh ◽  
J. R. Sommer

Cardiac sarcoplasmic reticulum (SR) is a complex system of intracellular tubules that, due to their small size and juxtaposition to such electron-dense structures as mitochondria and myofibrils, are often inconspicuous in conventionally prepared electron microscopic material. This study reports a method with which the SR is selectively “stained” which facilitates visualizationwith the transmission electron microscope.


Author(s):  
V. F. Allison ◽  
G. C. Fink ◽  
G. W. Cearley

It is well known that epithelial hyperplasia (benign hypertrophy) is common in the aging prostate of dogs and man. In contrast, little evidence is available for abnormal epithelial cell growth in seminal vesicles of aging animals. Recently, enlarged seminal vesicles were reported in senescent mice, however, that enlargement resulted from increased storage of secretion in the lumen and occurred concomitant to epithelial hypoplasia in that species.The present study is concerned with electron microscopic observations of changes occurring in the pseudostratified epithelium of the seminal vescles of aging rats. Special attention is given to certain non-epithelial cells which have entered the epithelial layer.


Author(s):  
Glennelle Washington ◽  
Philip P. McGrath ◽  
Peter R. Graze ◽  
Ivor Royston

Herpes-like viruses were isolated from rhesus monkey peripheral blood leucocytes when co-cultivated with WI-38 cells. The virus was originally designated rhesus leucocyte-associated herpesvirus (LAHV) and subsequently called Herpesvirus mulatta (HVM). The original isolations were from juvenile rhesus monkeys shown to be free of antibody to rhesus cytomegalic virus. The virus could only be propagated in human or simian fibroblasts. Use of specific antisera developed from HVM showed no relationship between this virus and other herpesviruses. An electron microscopic study was undertaken to determine the morphology of Herpesvirus mulatta (HVM) in infected human fibroblasts.


Author(s):  
Mitsuo Ohtsuki ◽  
Michael Sogard

Structural investigations of biological macromolecules commonly employ CTEM with negative staining techniques. Difficulties in valid image interpretation arise, however, due to problems such as variability in thickness and degree of penetration of the staining agent, noise from the supporting film, and artifacts from defocus phase contrast effects. In order to determine the effects of these variables on biological structure, as seen by the electron microscope, negative stained macromolecules of high density lipoprotein-3 (HDL3) from human serum were analyzed with both CTEM and STEM, and results were then compared with CTEM micrographs of freeze-etched HDL3. In addition, we altered the structure of this molecule by digesting away its phospholipid component with phospholipase A2 and look for consistent changes in structure.


Author(s):  
J. Frank ◽  
P.-Y. Sizaret ◽  
A. Verschoor ◽  
J. Lamy

The accuracy with which the attachment site of immunolabels bound to macromolecules may be localized in electron microscopic images can be considerably improved by using single particle averaging. The example studied in this work showed that the accuracy may be better than the resolution limit imposed by negative staining (∽2nm).The structure used for this demonstration was a halfmolecule of Limulus polyphemus (LP) hemocyanin, consisting of 24 subunits grouped into four hexamers. The top view of this structure was previously studied by image averaging and correspondence analysis. It was found to vary according to the flip or flop position of the molecule, and to the stain imbalance between diagonally opposed hexamers (“rocking effect”). These findings have recently been incorporated into a model of the full 8 × 6 molecule.LP hemocyanin contains eight different polypeptides, and antibodies specific for one, LP II, were used. Uranyl acetate was used as stain. A total of 58 molecule images (29 unlabelled, 29 labelled with antl-LPII Fab) showing the top view were digitized in the microdensitometer with a sampling distance of 50μ corresponding to 6.25nm.


Author(s):  
Kazuaki Misugi ◽  
Nobuko Misugi ◽  
Hiroshi Yamada

The authors had described the fine structure of a type of pancreatic islet cell, which appeared different from typical alpha and beta cells, and tentatively considered that this third type of granular cell probably represents the D cell (Figure 1).Since silver staining has been widely used to differentiate different types of pancreatic islet cells by light microscopy, an attempt to examine this staining reaction at the electron microscopic level was made.Material and Method: Surgically removed specimens from three infants who suffered from severe hypoglycemia were used. The specimens were fixed and preserved in 20% neutral formalin. Frozen sections, 30 to 40 micron thick, were prepared and they were stained by Bielschowsky's method as modified by Suzuki (2). The stained sections were examined under a microscope and islet tissues were isolated. They were fixed in 1% osmium tetroxide in phosphate buffer for one hour and embedded in Epon 812 following dehydration through a series of alcohols and propylene oxide.


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