1.Adulterated Hydroxypropyl Methyl Cellulose (HPMC) is different from pure hydroxypropyl Methyl Cellulose (HPMC).
Appearance: Pure Hydroxypropyl Methyl Cellulose (HPMC) looks fluffy and has a small bulk density, ranging from 0.3-0.4g/ml; The adulterated Hydroxypropyl Methyl Cellulose (HPMC) has better fluidity and a heavier feel, which is significantly different from the appearance of the genuine product.
Condition: Pure Hydroxypropyl Methyl Cellulose (HPMC) powder is fibrous under a microscope or magnifying glass; Whereas, adulterated Hydroxypropyl Methyl Cellulose (HPMC) can be observed under a microscope or magnifying glass as a granular solid or crystal.
Odor: pure Hydroxypropyl Methyl Cellulose (HPMC) cannot smell ammonia, starch and alcohols; Adulterated Hydroxypropyl Methyl Cellulose (HPMC) can smell a variety of flavors, and even if it is odorless, it will feel heavy to the touch.
Aqueous solution: pure Hydroxypropyl Methyl Cellulose (HPMC) aqueous solution is clear, high light transmittance, and water retention rate≧97%; The aqueous solution of adulterated Hydroxypropyl Methyl Cellulose (HPMC) is turbid, and the water retention rate is difficult to reach 80%.
2.The water retention of Hydroxypropyl Methyl Cellulose (HPMC) is distinguished from the advantages and disadvantages:
The water retention of Methyl Cellulose under high temperature conditions is an important indicator to distinguish the quality of Methyl Cellulose. Factors such as air temperature, humidity and wind pressure velocity affect the rate of water evaporation in cement mortar and gypsum-based products. Therefore, in different seasons, there are some differences in the water retention effect of adding the same amount of HPMC. In the specific construction, the water retention effect of the slurry can be adjusted by increasing or decreasing the amount of HPMC. Excellent Hydroxypropyl Methyl Cellulose (HPMC) products can effectively solve the problem of water retention at high temperatures.
High-quality Methyl Cellulose can be evenly and effectively dispersed in cement mortar and gypsum-based products, and wrap all solid particles, and form a wetting film, the moisture in the base is gradually released over a long period of time, and the hydration reaction with inorganic cementitious materials occurs, so as to ensure the bonding strength and compressive strength of the material. High-quality Hydroxypropyl Methyl Cellulose (HPMC), its uniformity is very good, its methoxy and hydroxypropoxy groups are evenly distributed along the cellulose molecular chain, it can improve the ability of the oxygen atoms on the hydroxyl and ether bonds to associate with water to form hydrogen bonds, so that the free water becomes bound water, so as to effectively control the evaporation of water caused by high temperature weather, and achieve high water retention.
Therefore, in the construction of high temperature summer, in order to achieve the effect of water retention, it is necessary to add high-quality HPMC products in sufficient amount according to the formula, otherwise, there will be quality problems such as insufficient hydration, reduced strength, cracking, hollowing and falling off caused by too fast drying, and at the same time, it will also increase the difficulty of construction for workers. As the temperature decreases, the amount of HPMC added can be gradually reduced, and the same water retention effect can be achieved.
3. Dissolution of Hydroxypropyl Methyl Cellulose (HPMC)
In the construction industry, Hydroxypropyl Methyl Cellulose (HPMC) is often put into neutral water, and the HPMC product is dissolved separately to determine the dissolution rate. After being put into neutral water alone, the product that is quickly grouped and not dispersed is a product without surface treatment; When placed in neutral water alone, it is a surface treatment product that can disperse the product without clumping. When the untreated Hydroxypropyl Methyl Cellulose (HPMC) on the surface is dissolved separately, its single particle dissolves quickly and forms a film quickly, resulting in the inability of water to enter other particles, resulting in agglomeration and agglomeration, which is currently called a slow-dissolving product on the market.
Surface-treated Hydroxypropyl Methyl Cellulose (HPMC) product granules, in neutral water, individual particles can disperse without agglomerating, but do not immediately produce viscosity. After a certain period of soaking, the chemical structure of the surface treatment is destroyed, and the water can dissolve the HPMC particles, and at this time, the product particles have been fully dispersed and absorb enough water, so the product will not agglomerate and agglomerate after dissolving. The dispersion speed and dissolution speed depend on the depth of the surface treatment, the surface treatment is slight, the dispersion speed is relatively slow, and the sticking speed is fast; For products with deep surface treatment, the dispersion speed is fast and the sticking speed is slow. If this series of products is to be dissolved quickly in this state, a small amount of alkaline substances can be dropped when they are dissolved separately. The current market is often referred to as instant products. The characteristics of surface-treated HPMC products are: in the aqueous solution, the particles can be dispersed with each other, in the alkaline state, it can be dissolved quickly, and in the neutral and acidic state, it can dissolve slowly.
The characteristics of untreated Hydroxypropyl Methyl Cellulose (HPMC) are: a single particle dissolves very quickly in the acidic, alkaline and neutral state, but it cannot be dispersed between particles in the liquid, resulting in clumping and agglomeration. In actual operation, after the series of products and solid particles such as rubber powder, cement, and sand are physically dispersed, the dissolution speed is very fast, and there is no agglomeration and agglomeration. When it is necessary to dissolve HPMC products separately, this series of products should be used with caution, it will clump and clump. If it is necessary to dissolve the untreated Hydroxypropyl Methyl Cellulose HPMC product separately, it is necessary to disperse it evenly with hot water at 95℃, and then cool it to dissolve.
In actual production operations, this series of products are often dissolved after dispersion with other solid granular materials under alkaline conditions, and its dissolution rate is no different from that of untreated products. It is also suitable for use in products that are dissolved separately without agglomeration or clumping. According to the dissolution speed required by construction, the specific model of the product can be selected.
In the construction process, whether it is cement mortar or gypsum-based slurry, most of them are alkaline systems, and the amount of HPMC added is very small, which can be evenly dispersed among these particles, and HPMC will dissolve quickly when water is added.
4.The main manufacturers and products analysis
The SIDLEYCHEM brand was successfully founded in 2012 and has built a matrix of world-renowned brands including SIDLEYCEL and SIDLEYRDP. After more than 10 years of steady development, SIDLEYCHEM’s business scope has been widely covered in cellulose ether series, mortar admixtures, coatings, daily chemicals, pharmaceuticals, food and oil drilling and other industries. Today, SIDLEYCHEM is poised to roll out its global footprint with the aim of winning wide acclaim and recognition in the industry and setting a new benchmark in the industry.
One of SIDLEYCHEM’s core strengths is its well-equipped and specialized laboratory, which plays an irreplaceable and critical role in responding to customer needs and driving new product development. The laboratory follows a strict product standard inspection process, which can comprehensively cover the testing and application evaluation of diversified products such as construction admixtures, coating additives, oil drilling additives, etc., to ensure that every link is accurate. We are committed to ensuring that the product performance perfectly meets the needs of customers through strict index control, and at the same time maintaining the lasting stability of the product and minimizing the trouble caused by the instability of the product. In order to achieve this goal, the laboratory conducts detailed physical and chemical experiments and application tests on each batch of products to ensure worry-free quality. Furthermore, according to the individual needs of customers, we provide consulting services for formula adjustment and cost optimization, so as to help customers achieve the best economic benefits.