Hydroxypropyl Methylcellulose Viscosity Research Articles

Modifying Cotton Fabric Properties by Controlling HPMC Viscosity Grade to Limit Ink Spreading and Penetration.

In cotton fabric inkjet printing, the spreading and penetration of the ink seriously damage printing resolution and color strength. In this study, hydroxypropyl methyl cellulose (HPMC) with varying viscosity grades (6, 30, 100, 400, and 4000 mPa·s) were used for fabric pretreatment to reduce the ink spreading and penetration. The results indicated that HPMC with a high viscosity grade enhanced the ability of pretreatment paste to form a continuous HPMC film on the fiber surface. A continuous film could greatly increase the hydrophobicity of the fabric, thereby restricting the spreading and penetration of ink. Meanwhile, ink migration was also limited by the paste connected to the fibers and the swelling of the film, which was more significant at higher HPMC viscosity grades. However, the increase of the HPMC viscosity grade was not conducive to dye fixation. Additionally, HPMC with a viscosity grade of 100 mPa·s was considered a reasonable choice, which could improve printing resolution and color strength in industrial applications. This research provides a new approach for optimizing pretreatment paste to achieve high-quality printed products.

Multivariate Analysis and Computational Predictability of Modified Release Formulation of Chirally Pure Metoprolol Succinate

This study employs computational techniques to predict the performance of a modified-release matrix formulation of chirally pure S (-) Metoprolol Succinate, using a Quality by Design (QbD) approach. The research defines the Quality Target Product Profile (QTPP) and Critical Quality Attributes (CQAs) of the S (-) Metoprolol Succinate matrix formulation. To assess risks, an Ishikawa diagram and Failure Mode Effect Analysis (FMEA) following ICH Q8 guidelines were conducted. The formulation screening process utilized Plackett–Burman design, followed by optimization through Box–Behnken design. The modified-release formulation was developed using high shear granulation, incorporating a combination of high and low viscosity Hydroxypropyl Methylcellulose (HPMC) polymers along with other excipients. The impact of polymer composition and stearic acid on the release profile of S (-) Metoprolol Succinate was investigated, revealing their significant influence on the drug delivery system's desired effect. Specifically, the variables X1: HPMC K4M and X2: HPMC K100M were identified as key factors affecting drug release (Y1). Statistical analysis (ANOVA) confirmed the significance of the selected model, with predicted outcomes aligning well with observed results, comparable to the reference product Seleken® XL range. Both drug content and release performance were found to be similar to the innovator formulation. In summary, this investigation underscores the potential of employing a QbD approach with a combination of low and high viscosity HPMC polymers to achieve precise single-dose delivery of S (-) Metoprolol Succinate.

Innovation in Green Materials for the Non-Contact Stabilization of Sensitive Works of Art: Preliminary Assessment and the First Application of Ultra-Low Viscosity Hydroxypropyl Methylcellulose (HPMC) by Ultrasonic Misting to Consolidate Unstable Porous and Powdery Media

Paintings and other works of art created with fragile and mechanically unstable powdery media present challenges to conservators. Frequently, powdery media is water-sensitive, extremely fragile, tends to delaminate, and may be altered by even the slightest physical action or interaction with liquids. Materials that can provide an efficient stabilization without unacceptably altering the optical characteristics of the delicate substrate are extremely limited. Among these, Funori, Isinglass, and Methocel A4C have become established for this use. In bench practice, consolidants are frequently applied in a non-contact way, using ultrasonic and pneumatic aerosol generators to minimize the impact of the consolidant on sensitive substrates. However, nebulizing the available materials is problematic in bench practice, because of their high viscosity and, only extremely low concentrations can be nebulized using low kinetic impact ultrasonic or pressure-based misting systems adopted from the healthcare industry. As a potential innovative solution, this study introduces novel ultra-low viscosity (ULV) cellulose ethers (ULV-HPMC) for stabilisation of unstable porous and powdery surfaces, which have been successfully applied in bench practice for the pilot treatment of Edvard Munch painting on canvas and two 19th c. Thai gouache paintings on panel. Novel ULV-HPMC materials have multiple desirable qualities for consolidation treatments in conservation, and in accelerated aging tests marginally outperformed Methocel A4C, considered to be one of the most stable consolidants in the practice of conservation. Because of the ultra-low viscosity, higher concentrations of ULV-HPMC materials can be applied as water-based aerosols in a non-contact way and in fewer applications, which is a significant advantage in the treatment of delicate water-sensitive surfaces. Notably, novel ULV biopolymers are low-cost, derive from sustainable and renewable sources, and do not raise health and environmental concerns. Such novel materials and methods seamlessly resonate with the ICOM-CC’s Melbourne 2014 declaration, EU Green Deal, and the UN’s Sustainable Development goals and show potential adding new sustainable materials with the exceptionally low viscosity to the conservator’s tool box.

Formulation Optimization of Solid Dispersion of Candesartan Cilexetil

Context: Antihypertensive effects were achieved by quickly hydrolyzing candesartan cilexetil (CC), an inactive prodrug of candesartan, into active candesartan during absorption in the gastrointestinal tract. Due to its weak water solubility, CC has an inadequate intestinal absorption and a low oral bioavailability. Aim: The goal of this study was to make the medication CC more soluble in water. Materials and Methods: Low viscosity hydroxypropyl methylcellulose (HPMC) E5LV was used to prepare the solid dispersions through spray drying. Results: Study of dissolution, Fourier transform infrared spectroscopy, scanning electron microscopy (SEM), differential scanning calorimeter (DSC), and X-ray diffraction characterized the prepared solid dispersions. CC amorphized from its crystallized state, as shown by the findings from the SEM, DSC, and X-ray powder diffraction experiments. Comparing pure CC and solid dispersion, the dissolution rate was higher with the former. The surfactant and wetting property of HPMC E5LV slowed devitrification and had an anti-plasticization impact, increasing the solubility and stability of the solid dispersion. Conclusion: The final results indicated that the CC, a weakly water-soluble medication, dissolved much better in the solid dispersions.

Drug-Polymers Composite Matrix Tablets: Effect of Hydroxypropyl Methylcellulose (HPMC) K-Series on Porosity, Compatibility, and Release Behavior of the Tablet Containing a BCS Class I Drug.

The purpose of this research was to see how the physicochemical properties and porosity of matrix tablets containing various types of hydroxypropyl methylcellulose (HPMC) K series affected the release of propranolol hydrochloride (PNL). PNL is a class I drug (high solubility and permeability) according to the Biopharmaceutics Classification System (BCS), making it an excellent model drug used for studying extended-release drug products. The direct compression method was used to prepare the HPMC-based matrix tablets. PNL and the excipients were found to be compatible using Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction (PXRD), and differential scanning calorimetry (DSC). The surfaces of all the compressed HPMC-based matrix tablets were rough, with accumulated particles and small holes. The compressed HPMC-based matrix tablet porosity was also determined by using mercury porosimetry. The compressed HPMC-based matrix tablets made of low viscosity HPMC had tiny pores (diameter < 0.01 μm). The shorter polymeric chains are more prone to deformation, resulting in a small pore proportion. The compressed HPMC-based matrix tablets sustained the release of PNL for over 12 h. The release exponent values (n), which reflect the release mechanism of the drug from the tablets, ranged from 0.476 to 0.497. These values indicated that the release was governed by anomalous transport. The compressed HPMC-based matrix tablets have the potential for a sustained release of PNL.

Observation of curcumin-loaded hydroxypropyl methylcellulose (HPMC) oleogels under in vitro lipid digestion and in situ intestinal absorption in rats

Curcumin-loaded nanostructured lipid carriers (Cur-NLCs)-based hydroxypropyl methylcellulose (HPMC) oleogels (Cur-NLCs-HPMC-OGs) were fabricated using a cryogel template. The effect of the HPMC viscosity grade on the oleogel characteristics and in situ intestinal absorption were examined. Highly stable Cur-NLCs were prepared with a mean particle size of 314 nm and polydispersity index of 0.275. Cur-NLCs affected the creamy texture of self-standing Cur-NLCs-HPMC-OGs. The Cur-NLCs were tightly packed as oil droplets in the network of HPMC. However, a high viscosity of HPMC-4000 led to a greater ability to entrap and prevent droplet coalescence compared to a low viscosity of HPMC-400. NLCs promoted the release of free fatty acids during in vitro lipid digestion, whereas HPMC-4000 maintained the strength and durability of oleogels against mechanical and enzymatic breakdown. The in situ loop results revealed higher curcumin absorption by Cur-NLCs-HPMC-OGs than by Cur-HPMC-OGs. HMPC-4000 showed slightly higher curcumin absorption compared to HPMC-400.

Role of physicochemical properties of some grades of hydroxypropyl methylcellulose on in vitro mucoadhesion

Relationships between physicochemical properties of hydroxypropyl methylcellulose (HPMC) compacts and their in vitro mucoadhesive performances were investigated in this study. Some commercial grades of HPMC (K3, E3, E5, E50, K4M, E4M and K15M) were prepared into compacts, and their surface hydrophilicity and hydration behavior were characterized. The in vitro mucoadhesive performance was determined by the tensile strength between the compacts and different regions of mucosal membrane (buccal, sublingual, stomach, and intestine). Positive correlations were found between: (1) viscosity of HPMC compacts and contact angle in different simulated body fluids; (2) viscosity of HPMC compacts and in vitro mucoadhesive force; (3) contact angle and in vitro mucoadhesive force. The hydration increased with an increase in viscosity of HPMC compacts. The polar lipid content in mucosa was found to be an important factor affecting the mucoadhesion. Lower polar lipid amount in the mucosal membrane promoted the rate of mucoadhesive force with the increasing viscosity of HPMC. The mucoadhesive mechanism of various grades of HPMC compacts were studied using the thermodynamic analysis of Lifschitz-van der Waals (LW) interaction and Lewis acid-base (AB) interactions. The total free energy of adhesion (ΔGTOT) provided a prediction of an overall tendency of mucoadhesion, and deviated from the measured mucoadhesive force.

Formulation of Sustained Release Hydrophilic Matrix Tablets of Tolcapone with the Application of Sedem Diagram: Influence of Tolcapone's Particle Size on Sustained Release.

Hydrophilic matrix tablets are a type of sustained release dosage form characterized by distributing a drug in a matrix that is usually polymeric. Tolcapone is a drug that inhibits the enzyme catechol-O-methyl transferase. In recent years, it has been shown that tolcapone is a potent inhibitor of the amyloid aggregation process of the transthyretin protein, and acts by stabilizing the structure of the protein, reducing the progression of familial amyloid polyneuropathy. The main objective of this study was to obtain a sustained release tablet of tolcapone for oral administration with a preferred dosage regimen of 1 administration every 12 or 24 h and manufactured, preferably, by direct compression. The SeDeM Diagram method has been used for the formulation development of hydrophilic matrix tablets. Given the characteristics of tolcapone, the excipient selected for the formation of the polymeric matrix was a high viscosity hydroxypropylmethylcellulose (Methocel® K100M CR). A decrease in the particle size of tolcapone resulted in a slower dissolution release of the formulation when the concentration of the polymer Methocel® K100M CR was below 29%. These surprising and novel results have given rise to patent number WO/2018/019997.

Design of multi-particulate "Dome matrix" with sustained-release melatonin and delayed-release caffeine for jet lag treatment.

Multi-particulate Dome matrix with sustained-release melatonin and delayed-release caffeine was designed to restore jet lag sleep-wake cycle. The polymeric pellets were produced using extrusion-spheronization technique and fluid-bed coated when applicable. The compact and Dome module were produced by compressing pellets with cushioning agent. Dome matrix was assembly of modules with pre-determined compact formulation and drug release characteristics. The physicochemical and in vivo pharmacokinetics of delivery systems were examined. Melatonin loaded alginate/chitosan-less matrix exhibited full drug release within 8h gastrointestinal transit with low viscosity hydroxypropymethylcellulose as cushioning agent. The cushioning agent reduced burst drug release and omission of alginate-chitosan enabled full drug release. Delayed-release alginate-chitosan caffeine matrix was not attainable through polymer coating due to premature coat detachment. Admixing of cushioning agent high viscosity hydroxypropylmethylcellulose and high viscosity ethylcellulose (9:1wt ratio) with coat-free caffeine loaded particulates introduced delayed-release response via hydroxypropylmethylcellulose swelled in early dissolution phase and ethylcellulose sustained matrix hydrophobicity at prolonged phase. The caffeine was released substantially in colonic fluid in response to matrix polymers being degraded by rat colonic content. Dome matrix with dual drug release kinetics and modulated pharmacokinetics is produced to introduce melatonin-induced sleep phase then caffeine-stimulated wake phase.

Soil infiltration and conservative solute transport characteristics with different viscosity of hydroxypropyl methyl cellulose

AbstractHydroxypropyl methyl cellulose (HPMC), a potential soil improver with the ability to hold water, has practical applicability in alleviating soil and water nutrient loss. By using Cl− as tracer ions, we evaluated the effects of different HPMC viscosities on soil water infiltration characteristics and conservative solute migration characteristics. Hydroxypropyl methyl cellulose with viscosities of 2 × 104, 6 × 104, 10 × 104, and 20 × 104 mPa s−1 was selected. Experimental results revealed that the cumulative infiltration amount, wetting front migration distance, and infiltration rate decreased significantly with increased HPMC viscosity. The addition of HPMC delayed the soil solute transport process, and HPMC with a higher viscosity caused greater soil solute transport delay. Both the convection‐dispersion equation (CDE) and the two‐region model (TRM) accurately simulated solute transport, but the simulation accuracy of the TRM was higher. Results of parametric fitting based on the TRM indicated that the average pore water velocity, hydrodynamic dispersion coefficient, and dispersion degree decrease with increased HPMC viscosity. The average pore water velocity decreased by 13.6–28.2% relative to the control group (CG). Compared with the CG, the water content ratio in movable water of HPMC groups changed irregularly with an increase in viscosity. The mass exchange coefficient increased significantly compared with the CG, with an irregular trend. These data will be useful in the application and promotion of HPMC as a soil improver.

Study of the influence of cellulose derivatives on physical and analytical attributes of a drug product belonging to BCS class II.

Cellulose microcrystalline (MCC), hydroxypropyl methylcellulose (HPMC) and croscarmellose sodium are cellulose derivatives which are widely used in pharmaceutical technology. Although they are inert pharmaceutical ingredients, they can influence the release profile of an active substance from the dosage form depending on their distribution, type and quantity used in the formulation. The aim of the present investigation was to examine the effect of chosen cellulose derivatives on the physical and analytical attributes of a drug product containing an active substance of Biopharmaceutics Classification System (BCS) class II. The tablets were prepared using the wet granulation technology. The batches differed in the amount and grade of HPMC, the type of MCC and the distribution of croscarmellose sodium. The granule properties as well as physical (tablet hardness, disintegration time, friability) and analytical (dissolution profile in different media) attributes of the tablets were examined. The flow characteristics were satisfying in the case of all prepared batches. However, the differences in flow properties were visible, especially in the cases where MCC of coarser particles was replaced with MCC of finer particles. The type of MCC used in the product formula also had a significant influence on the drug product dissolution profile. The batches in which MCC of finer particles was used had substantially better results, regardless of HPMC viscosity type and the distribution of croscarmellose sodium between the inner and outer phase. What is more, the differences in the results between batches of different MCC types were especially visible in dissolution conditions, i.e., 0.1N hydrochloric acid (HCl). By choosing the right type, quantity and distribution of cellulose derivatives, it was possible to obtain the optimal formula of the drug product similar to in-vitro conditions to the reference drug. Out of all the tested excipients, the type of cellulose microcrystalline was found to have the most critical influence on both physical and analytical properties of the pharmaceutical formulation.

Convergence Study on In Vitro Lipid Digestibility of Instant Fried Noodle with HPMC

The effects of HPMC (hydroxypropyl methylcellulose) on instant fried noodles regarding oil uptake and in vitro lipid digestibility were evaluated according to different viscosity levels, as well as the same apparent viscosity. The oil uptake and lipid digestibility decreased with the increasing HPMC viscosity and replacement level, demonstrating that the reduced oil uptake and lipid digestibility may be caused by the high viscosity of HPMC. Furthermore, the oil uptake and lipid digestibility of noodles with HPMC at both apparent viscosities decreased with the increasing viscosity of HPMC in spite of having the same apparent viscosity. As a result, the high viscosity of HPMC on instant fried noodles was more critical factor compared to apparent viscosity for lowering oil uptake and lipid digestibility.

Probing the impact of HPMC viscosity grade and proportion on the physical properties of co-freeze-dried mannitol-HPMC tableting excipients using multivariate analysis methods

This study investigated the impact of hydroxypropyl methylcellulose (HPMC) viscosity grade, HPMC proportion and particle size fraction on the physical properties of the freeze-dried mannitol-HPMC excipients produced, using multivariate analysis methods. Solutions containing 20%, w/w mannitol-HPMC were freeze-dried and milled to obtain excipients of size fractions 125–355 μm and 355–710 μm to understand the impact of the formulation variables on the molecular, particle and bulk properties of the excipients. Results showed that the freeze-dried mannitol-HPMC excipients were mainly differentiated by 3 overarching properties, in the order of their contribution to the variation in the principal component analysis (PCA) model: (i) freeze-dried cake strength and bulk fill-related properties, (ii) compression behaviour-related properties, and (iii) flow-related properties. These properties were influenced by the HPMC viscosity grade, HPMC proportion and size fraction of excipient used. Freeze-dried excipients containing vLV or lower HPMC proportions had higher bulk densities, thus displaying better packing within the die. For larger excipients, densification by plastic deformation was likely preceded by fragmentation, thus accounting for the higher yield pressure values. The establishment of inter-variable relationships between the physical properties would be useful in further studies on the functional properties of tablets containing these co-freeze-dried mannitol-HPMC tableting excipients.

Understanding the role of hydrocolloids viscosity and hydration in developing gluten-free bread. A study with hydroxypropylmethylcellulose

To understand the role of hydrocolloids' viscosity in developing gluten-free (GF) bread, a range of hydroxypropylmethylcellulose (HPMC) with similar backbone and percentage of methoxyl and hydroxypropoxyl residues was selected in order to vary the viscosity (100 mPa.s, 4000 mPa.s, 15,000 mPa.s) while keeping the main chemical structure. Viscosity of HPMC was used as quantitative independent factor in a multilevel factorial model along with HPMC level (1%, 2%, 3%) and hydration level (90%, 100%, 110%). The model results in 27 formulation based on rice flour. A Mixolab system was uses to analyse the rheological parameters of the GF batters during mixing, cooking and cooling stage. In addition, GF breads were characterised for their quality parameters. Analytical data were fitted to multiple regression equations in order to estimate the dependence of the collected parameters on the quantitative independent factors. Results confirmed the importance of hydration level in determining the viscoelastic behaviour of the GF batter and influencing the rheology characteristics of bread. Moreover, it was possible to underline the role of the HPMC viscosity along with the level of HPMC, both to control the batter consistency and some desirable textural features of GF bread such as crumb hardness, cohesiveness and resilience. Finally, some analytical parameters were used as quality indicators in desirability index calculation, which would represent a GF breads with optimum quality obtained by the inclusion of a 2.2% of HPMC 15000 cP with hydration level to 110%.

Tablets of paliperidone using compression-coated technology for controlled ascending release

The aim of this work was to prepare ascending release compression-coated (CC) tablets with paliperidone (PAL) using a simple manufacturing technique and short manufacturing process. The release behavior and mechanisms in vitro of the final tablets was investigated and evaluated. The PAL CC tablets were comprised of a core layer of high viscosity hydroxypropyl cellulose (HPC-H) and a coating layer of high viscosity hydroxypropyl methylcellulose (HPMC-K100M). Several factors such as materials and core tablet compositions were studied for their influence in the formulation procedure. The drug release mechanism was studied using gravimetric analysis. The data could be fitted to the Peppas model. The ascending drug release results were expressed in terms of the slope of the release curve at different time points. Results showed that the formulation could achieve a good ascending drug release when the weight ratio of PAL was 5:1 (core:layer). The fraction of HPC and HPMC was 33 %, and the combination of Eudragit RL-PO was 10%. The ascending release mechanism was due to solvent penetration into the PAL CC tablets, and subsequent drug dissolution from the gelatinous HPC and HPMC matrix erosion. The release mechanism was therefore a combination of diffusion and erosion. This work demonstrated that the compression-coated tablets could achieve controlled ascending release over 24 h for the oral administration systems.

Macro-micro structure characterization and molecular properties of emulsion-templated polysaccharide oleogels

Emulsion and oleogels prepared at a constant xanthan gum (XG) concentration of 0.3 wt%, and varying hydroxypropyl methyl cellulose (HPMC) concentration of 0.2, 0.4, 0.6, 0.8 and 1.0 wt% were evaluated for their macro-micro structure and molecular properties, respectively. Rheological behaviors of the emulsions and oleogels were tested for their gel strength. Oil loss of the oleogel was measured to evaluate their oil binding capacity. Polarizing light microscope (PLM) and scanning electron microscope (SEM) were used to investigate the microstructure of the samples. Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) measurements were used to further understand the structure of the oleogels. Macro properties and microstructure of the samples were linked with each other, and HPMC concentration had a prominent effect on the microstructure and rheological properties of the emulsions, dried products and oleogels. Higher concentration of HPMC resulted in more stable emulsion with higher mechanical strength, hard dried products with more compact network, and oleogels with higher mechanical strength and better oil binding capacity. The effect of HPMC concentration on the properties of samples was irrelevant to the viscosity of HPMC. The oleogel prepared was a physical gel, and intramolecular or intermolecular hydrogen bonding presented in the oleogel contributed to its relatively orderly structure with liquid oil trapped in it. The oil droplets were coated by the hard layer formed by polysaccharides. This research gave more information about polymer based oleogels and provided a reference for their application.

Drug release behavior of polymeric matrix filled in capsule

A single unit sustainable drug release system was developed using hydroxypropyl methylcellulose (HPMC)-based matrices filled in capsule as the drug delivery device. Release behavior of propranolol HCl from these capsules was investigated and least square fitting was performed for the dissolution data with the different mathematical expressions. Effect of diluent, polymer, pH and hydrodynamic force on the drug release from the developed systems was investigated. The utilization of HPMC as a matrix former extended the drug release longer than 8h. HPMC viscosity grades affected the drug release, that is, increasing the amount of fillers such as lactose and dibasic calcium phosphate enhanced the drug release rate of HPMC matrices. The hydrodynamic force, type and amount of incorporated polymer apparently influenced the drug release. The physiochemical properties of polymers and interaction between HPMC and other polymers were important factors for prolongation of the drug release. The release mechanism from HPMC-based matrices in capsules was the non-Fickian transport in which the sustainable drug release of HPMC capsules could be achieved by the addition of polymeric matrix.

Stability of β-carotene loaded emulsions vary by viscosity of hydroxypropyl methylcellulose dispersions

The physical stability of oil-in-water emulsions containing β-carotene was investigated to assess the emulsification of three hydroxypropyl methylcellulose (HPMC) of varying substitution and viscosity and gum acacia (GA) control dispersions. Initially, emulsions stabilized with GA had particle sizes of 0.79 μm, whereas the HPMC stabilized emulsions possessed particle sizes of about 1.38–1.96 μm. Following storage at 25 °C or 37 °C for up to 12 days, no significant differences between the initial and final particle sizes for two of the three HPMC stabilized emulsions (P < 0.05) were observed and remained <2.0 μm. However, the particle size distributions changed with time of storage at 25 °C or 37 °C in all emulsions, but were minimal in the emulsion containing the highest initial viscosity HPMC (0.401 Pa s). Images from light microscopy demonstrated that variability in droplet sizes was more prominent in low viscosity, low M:HP HPMC stabilized emulsions. Small amplitude oscillatory shear measurements revealed that the HPMC that possessed a viscosity of 0.401 Pa s and high M:HP (4.45) displayed characteristics of a weak gel network, which likely provided additional resistance against particle size increase. The analysis of the data demonstrates that HPMC with high viscosity, high M:HP produce emulsions with greater physical stability.

Properties of ceramic tile adhesives modified by different viscosity hydroxypropyl methylcellulose

Special mortars for fixing ceramic tiles on different substrates, mainly concrete, are very important in house building sector. Besides the binding materials, cement most of all, additives and admixtures that allow to model proper properties of such mortars are used for the manufacture. Methylcellulose is one of the most frequently used admixture for modification of mortars properties. Influence of different admixtures, redispersible powders for instance or other organic compounds containing polymers, on the hydration process of cement and properties of obtained mortars has been an object of many investigations. Methylcellulose is a very important constituent of adhesives despite the fact that its content is very low, normally below tenth of mass percent of dry material. Use of that admixture allow to obtain good performance of mortars. Thanks to methylcellulose mortars are easy to prepare, comfortable in use and easy to handle, which provides obtaining of proper properties and causes that they are most frequently used. Cement based ceramic tile adhesives belong to that group. Results of laboratory experiments concerning influence of water solutions of methylcellulose on chosen physical properties and microstructure of cement based ceramic tile adhesives are presented in the paper.

Study on Aqueous Viscosity Behaviors of Hydroxypropyl Methylcellulose Hydrosol and Konjac Glucomanan Hydrosol

In this work, the viscosity behavior of hydroxypropyl methylcellulose (HPMC) and konjac glucomanan (KGM) hydrosol was studied. Effects of mass fractions, water quality and sodium chloride (NaCl) on the viscosity of hydrosol were investigated by rotating viscometer. The results indicated that the viscosity of KGM and HPMC apparently increased with the increasing of mass fraction. HPMC could always maintain high viscosity in various kinds of water, whereas the viscosity of KGM reduced in tap water. The salt resistance experiments shown that the viscosities of the two kinds of hydrosol with 0.9% NaCl appeared a little decrease, hence, all hydrosols have a good salt resistance.