The Influence of Stabilizing Agents on the Interaction between Styrene/Butadiene Latex and Calcium Carbonate: A Calorimetric and a Dynamic Electrokinetic Study

2002 ◽  
Vol 254 (1) ◽  
pp. 8-16 ◽  
Author(s):  
Kaj Backfolk ◽  
Serge Lagerge ◽  
Jarl B. Rosenholm
TAPPI Journal ◽  
2011 ◽  
Vol 10 (7) ◽  
pp. 29-34
Author(s):  
TEEMU PUHAKKA ◽  
ISKO KAJANTO ◽  
NINA PYKÄLÄINEN

Cracking at the fold is a quality defect sometimes observed in coated paper and board. Although tensile and compressive stresses occur during folding, test methods to measure the compressive strength of a coating have not been available. Our objective was to develop a method to measure the compressive strength of a coating layer and to investigate how different mineral coatings behave under compression. We used the short-span compressive strength test (SCT) to measure the in-plane compressive strength of a free coating layer. Unsupported free coating films were prepared for the measurements. Results indicate that the SCT method was suitable for measuring the in-plane compressive strength of a coating layer. Coating color formulations containing different kaolin and calcium carbonate minerals were used to study the effect of pigment particles’ shape on the compressive and tensile strengths of coatings. Latices having two different glass transition temperatures were used. Results showed that pigment particle shape influenced the strength of a coating layer. Platy clay gave better strength than spherical or needle-shaped carbonate pigments. Compressive and tensile strength decreased as a function of the amount of calcium carbonate in the coating color, particularly with precipitated calcium carbonate. We also assessed the influence of styrene-butadiene binder on the compressive strength of the coating layer, which increased with the binder level. The compressive strength of the coating layer was about three times the tensile strength.


2011 ◽  
Vol 415-417 ◽  
pp. 237-242
Author(s):  
Zhou Da Zhang ◽  
Xue Mei Chen ◽  
Guo Liang Qu

Calcium carbonate nanoparticles (nano-CaCO3) filled powdered styrene-butadiene rubber (P(SBR/CaCO3) was prepared by adding nano-CaCO3 particles, encapsulant and coagulant to styrene-butadiene rubber (SBR) latex by coacervation, and the particle size distribution, structure were studied. Scanning electron microscopy (SEM) was used to investigate the (P(SBR/CaCO3) particle structure, and a powdering model was proposed to describe the powdering process. The process includes: (i) the latex particles associated with the dispersed nano-CaCO3 particles (adsorption process) to form “new particles” and (ii) the formation of P(SBR/CaCO3) by coagulating “new particles”. The SEM results also shown that the nano-CaCO3 and rubber matrix have formed a macroscopic homogenization in the (P(SBR/CaCO3) particles and nano-CaCO3 dispersed uniformly in the rubber matrix with an average diameter of approximately 50 nm.


2017 ◽  
Vol 36 (5) ◽  
pp. 251-268 ◽  
Author(s):  
Maryam Vahidi ◽  
Hamed Azizi

In this study, nanocomposite foams based on styrene-butadiene-styrene (SBS) copolymer and nanosized calcium carbonate (CaCO3) were prepared using chemical blowing agent (modified Azodicarbonamide) by compression molding at (230°C) temperature and (30MPa) pressure. The effect of nano CaCO3 concentration on cell nucleation rate, foam density, morphology and mechanical properties were studied for all samples. It was found that foam morphology and strength affected by nanofiller addition and its concentration. The results showed that SBS nanocomposite foam with 5 phr of CaCO3 nanoparticles have more cell density and smaller size cells compared with another samples. mechanical properties in compressive mode for foams were improved by increasing nano calcium carbonate content.


2013 ◽  
Vol 687 ◽  
pp. 329-334 ◽  
Author(s):  
Xu Bo Yue ◽  
Ru Wang

Tricalcium silicate (C3S) was synthesized at 1500oC using calcium carbonate and silicon oxide. The formation of the hydrates of C3S in the presence of 10% styrene-butadiene rubber (SBR) latex was evaluated. The morphology of the calcium silicate hydrate (C-S-H) was studied using SEM, and the calcium to silica ratio of the C-S-H was studied using EDS. The results show that the SBR latex forms film on the surface of the C3S particles and the C-S-H and delays the hydration of C3S. The C-S-H in the paste modified by SBR latex is shorter and thicker than that in the control at the same hydration time. After 1 day, the calcium to silica ratio of the modified paste is higher than that of the control.


2011 ◽  
Vol 99-100 ◽  
pp. 1035-1038 ◽  
Author(s):  
Nian Feng Han ◽  
De Jie Zhou ◽  
Xin De Tang

Composite modified asphalts with nano calcium carbonate (nano CaCO3)/ SBS and nano montmorillonite (nano MMT)/SBS were prepared respectively by melt blending. Rolling thin film oven test (RTFOT) was carried out to study the aging properties. The results demonstrate that CaCO3/SBS and MMT/SBS homogeneously disperse in the base asphalt, which lead to an improvement in terms of toughness, strength, and thermal stability. Effects of the nano CaCO3 and nano MMT on the properties of SBS modified asphalt appear as a decreasing penetration, an increasing softening point, and a decreasing ductility. The anti-aging property of the nano MMT/SBS modified asphalt was better than that of the CaCO3/SBS modified asphalt and SBS modified asphalt.


2014 ◽  
Vol 20 (4) ◽  
pp. 1571-1576 ◽  
Author(s):  
Huan Zhao ◽  
Qingxi Hou ◽  
Yimei Hong ◽  
Wei Liu ◽  
Yang Li ◽  
...  

Author(s):  
S. Q. Xiao ◽  
S. Baden ◽  
A. H. Heuer

The avian eggshell is one of the most rapidly mineralizing biological systems known. In situ, 5g of calcium carbonate are crystallized in less than 20 hrs to fabricate the shell. Although there have been much work about the formation of eggshells, controversy about the nucleation and growth mechanisms of the calcite crystals, and their texture in the eggshell, still remain unclear. In this report the microstructure and microchemistry of avian eggshells have been analyzed using transmission electron microscope (TEM) and energy dispersive spectroscopy (EDS).Fresh white and dry brown eggshells were broken and fixed in Karnosky's fixative (kaltitanden) for 2 hrs, then rinsed in distilled H2O. Small speckles of the eggshells were embedded in Spurr medium and thin sections were made ultramicrotome.The crystalline part of eggshells are composed of many small plate-like calcite grains, whose plate normals are approximately parallel to the shell surface. The sizes of the grains are about 0.3×0.3×1 μm3 (Fig.l). These grains are not as closely packed as man-made polycrystalline metals and ceramics, and small gaps between adjacent grains are visible indicating the absence of conventional grain boundaries.


Author(s):  
John G. Sheehan

The goal is to examine with high resolution cryo-SEM aqueous particulate suspensions used in coatings for printable paper. A metal-coating chamber for cryo-preparation of such suspensions was described previously. Here, a new conduction-cooling system for the stage and cold-trap in an SEM specimen chamber is described. Its advantages and disadvantages are compared to a convection-cooling system made by Hexland (model CT1000A) and its mechanical stability is demonstrated by examining a sample of styrene-butadiene latex.In recent high resolution cryo-SEM, some stages are cooled by conduction, others by convection. In the latter, heat is convected from the specimen stage by cold nitrogen gas from a liquid-nitrogen cooled evaporative heat exchanger. The advantage is the fast cooling: the Hexland CT1000A cools the stage from ambient temperature to 88 K in about 20 min. However it consumes huge amounts of liquid-nitrogen and nitrogen gas: about 1 ℓ/h of liquid-nitrogen and 400 gm/h of nitrogen gas. Its liquid-nitrogen vessel must be re-filled at least every 40 min.


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