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Complete comparison between HEMC (hydroxyethyl methyl cellulose) and VSHEC (hydroxyethyl cellulose)

1、 The essential difference in chemical structure

HEC hydroxyethyl cellulose is a pure hydrophilic structure with only hydroxyethyl (- CH ₂ CH ₂ OH) substitution, no methyl hydrophobic groups, and completely non-ionic. Molecular formula abbreviation: Cell-O-CH ₂ CH ₂ OH

HEMC hydroxyethyl methyl cellulose (also known as MHEC) double substitution: hydroxyethyl+methyl (- CH3) coexist, half hydrophilic and half weakly hydrophobic, also non-ionic cellulose ether. Molecular formula abbreviation: Cell-O-CH ∝+Cell-O-CH ₂ CH ₂ OH

One sentence summary: HEMC=HEC+methyl hydrophobic modified version, with performance between HEC and HPMC.

2、 Comparison Table of Core Performance Items (with a Focus on Adapting to Acrylic Sealing Filler System)

Comparison project HEC hydroxyethyl cellulose HEMC hydroxyethyl methyl cellulose

The cold water solubility is excellent, both cold and hot water can be dissolved, and the solubility transparency is the highest. It is not easy to be lumped and can be dissolved in cold water. At high temperature, hot gel will precipitate, and the transparency is slightly lower than HEC

The compatibility of the lotion system is optimal. There is almost no conflict between acrylic lotion, silane, dispersant and defoamer. The pH 7 – 9 is perfect and well matched, but the methyl hydrophobic group will slightly reduce the transparency of the lotion. A small amount of high silicon silane needs to be tested

Medium water retention capacity, focusing on coating anti water separation, slow surface drying, extremely strong, close to HPMC, high temperature environment water locking ability, crushing HEC

Poor resistance to enzymatic degradation/mold, with many hydrophilic groups, easily decomposed and reduced viscosity by microorganisms during high-temperature storage. It is necessary to add BIT preservative, which is excellent. The methyl hydrophobic structure hinders enzyme erosion, and the thermal storage viscosity stability is better. The probability of odor and viscosity reduction is greatly reduced

Pseudo plasticity/thixotropy recovery shows significant shear viscosity reduction, smooth scraping and coating, but static anti sagging and anti collapse are weaker, resulting in higher yield values and faster thixotropy recovery. Vertical gluing, joint filling, anti sagging and anti collapse are better than HEC

Thermal stability (high temperature storage) Stable at room temperature, 50 ℃ long-term hot storage viscosity attenuation is obvious, and the temperature of thermal gel is higher. The viscosity of high-temperature storage in summer fluctuates less and is not easy to become thin

Water resistance (dry film): The dry film has a high hydrophilicity, and after immersion in water, it slightly absorbs water and expands. The methyl group brings hydrophobicity, and the cured joint filler has better water resistance and water immersion resistance

The problem of bubble entrainment is extremely hydrophilic, making it easy for bubbles to be trapped when stirred, and the risk of pinholes is slightly higher. The hydrophobicity is improved, and there are fewer bubbles trapped, resulting in lower defoaming pressure

Thickening mechanism: dual effects of pure water hydrogen bonding thickening, hydrogen bonding thickening, and weak hydrophobic association

Incompatibility: excessive high silicon defoamer, strong acid pH<6, strong alkali environment, high temperature feeding, easy gel

Simplify 3 core performance differences

HEC: more hydrophilic, more transparent, acrylic lotion compatible ceiling, short board is afraid of high temperature, easy to be degraded by microorganisms, and water retention is general

HEMC: With methyl hydrophobic modification, it has strong water retention, enzyme resistance, stable heat storage, good dry film water resistance, stronger anti sagging, slightly poor transparency of short board, and high temperature gel

3、 Add quantity range

1. Water based acrylic sealant/grout

HEC: 0.2% to 0.8% (upper limit of 0.8%, only used for auxiliary settling and water retention)

HEMC: 0.15% to 0.6% (slightly higher thickening efficiency, slightly lower dosage)

2. Latex paint and water-based coating

HEC：0.3%～1.0%

HEMC：0.2%～0.7%

3. Cement based dry powder mortar (tile adhesive, putty, grout)

HEC is rarely used; HEMC typically ranges from 0.1% to 0.4%, with a focus on high-temperature water retention and extended opening time.

4、 Each with precise application scenarios

（1） HEC prioritizes selecting scenarios

1. Single component acrylic sealing sealant, elastic pointing paste, internal and external wall emulsion paint, water-based industrial paint, water-based color paste and emulsion primer are preferred for pure water-based acrylic lotion system. Reason: No flocculation with anionic acrylic acid lotion, silane adhesion promoter and various dispersants, high transparency of the paste, smooth scratch and smooth hand feel.

2. For products that require high transparency in appearance, such as transparent sealant and light colored pure white grout, HEC will not cause the paste to become cloudy.

3. Low temperature production and room temperature storage are the main methods, with no prolonged exposure to high temperatures. The workshop is kept at a constant temperature and the warehouse is cool, without the need to withstand long-distance transportation during high temperatures in summer.

4. Personal care, daily chemical thickening (attached) shampoo, bath gel, water-based gel, and industry general HEC.

Do not use HEC short board scenarios: outdoor joint filler (insufficient water resistance), high temperature southern storage, cement-based dry powder mortar.

（2） HEMC prioritizes scene selection

1. Upgraded acrylic sealing sealant (most recommended as a substitute for HEC)

Outdoor door and window weather resistant sealant, kitchen and bathroom long-term water immersion grout

Advantages of high temperature production/warehousing and long-distance logistics in the south due to viscosity attenuation: resistance to enzyme degradation and less odor, stable viscosity during thermal storage, better water resistance of dry film, stronger resistance to collapse during vertical construction, and fewer bubbles.

2. Cement based dry powder building materials

Ceramic tile adhesive, exterior wall putty, plastering mortar, cement-based jointing agent, self leveling mortar. Advantages: Super strong water retention, delaying rapid cement hydration and cracking, longer opening time for high-temperature construction, and anti slip movement of ceramic tiles.

3. Water based coatings with high water resistance requirements

Exterior wall elastic waterproof coating, water-based floor primer, high stain resistant exterior wall latex paint.

4. Add the desired formula to reduce the amount of preservatives

HEMC has strong resistance to mold, and BIT preservative can be slightly reduced in dosage.

HEMC short board scene caution: ultra-high transparency transparent glue, low-temperature repeated cold and hot cycle severe system (thermal gel characteristics).

5、 Conclusion on the ground selection of acrylic sealant

Option 1: Conventional Indoor Economy Type → Use HEC

Matching: mainly HEUR polyurethane association thickener (0.6 – 1.8%)+HEC auxiliary 0.3 – 0.6% Advantages: full compatibility of lotion, transparent paste, lower cost; Supporting requirements: BIT preservative 0.15-0.25% must be added to prevent degradation and viscosity reduction.

Option 2: Outdoor/High Temperature Storage/High Water Resistance Upgraded Version → Replace with HEMC

Combination: HEUR as the main component+HEMC0.2-0.5% profit:

(1) The viscosity of the warehouse remains basically unchanged after being stored for one month in summer;

(2) The finished product does not crack when soaked in water and has a lower water absorption rate;

(3) Less stirring bubbles and reduced pinhole defects;

(4) The risk of microbial spoilage has significantly decreased.

Absolutely not recommended for operation

A large number of pure acrylic acid lotion systems are mixed with HPMC (hydroxypropyl methyl cellulose), which is very easy to precipitate at high temperature, lose luster of lotion, and silane failure; When the water temperature of HEMC feeding exceeds 60 ℃, the direct gel agglomeration cannot be dissolved; Two types of cellulose are mixed in large quantities at the same time, causing rheological disorders and resulting in thickening and loss of drawing control.