What changes occur in the properties of cellulose during the storage process of washing and daily chemical products? ​

celluloseThe performance changes of functional ingredients such as anti redeposition agents and thickeners commonly used in washing and daily chemical products, such as sodium carboxymethyl cellulose (CMC) and hydroxypropyl methyl cellulose (HPMC), during storage depend on the temperature and humidity of the storage environment, packaging sealing, and whether they come into contact with impurities. The changing trends and influencing factors can be analyzed in detail from the following dimensions:

1、 Main performance changes and manifestations

1. Moisture absorption agglomeration and decreased solubility

Cellulose materials, especially ionic cellulose such as CMC, have strong hygroscopicity. If stored in a high humidity environment (relative humidity>60%) or packaged improperly, they will continue to absorb moisture from the air, causing powdery cellulose to clump and aggregate. After agglomeration, cellulose is difficult to quickly disperse and dissolve during subsequent liquid preparation and use, easily forming "fish eye" insoluble substances. This not only reduces the uniformity of the washing product, but also affects its core functions such as anti redeposition and thickening. For example, when washing clothes, undissolved cellulose lumps may adhere to the surface of the fabric, causing residual marks.

2. Chemical stability degradation (hydrolysis, oxidation)

Hydrolysis reaction: Under high temperature (>35 ℃), high humidity, or contact with acidic/alkaline impurities, the ether bonds of cellulose are prone to hydrolysis and breakage, resulting in shorter molecular chains and a decrease in molecular weight. This is manifested as a significant decrease in thickening ability (such as a decrease in viscosity of laundry detergent and dishwashing detergent), and a deterioration in anti redeposition effect (dirt is easily reattached after washing clothes), especially in alkaline washing product systems, where high temperature and high humidity can accelerate this process.

Oxidation reaction: If there is oxygen, light (especially ultraviolet light), or oxidative impurities (such as chlorine bleach and peroxides) in the storage environment, the hydroxyl groups in the cellulose molecular chain are easily oxidized, generating carboxyl groups and other functional groups, leading to an imbalance in its hydrophilicity - which may result in abnormal solubility (excessive dissolution leading to a sudden drop in viscosity, or even worse solubility due to molecular cross-linking), and the anti redeposition function may fail due to the destruction of molecular structure.

3. Decreased functional efficiency

Anti redeposition performance: The core function of cellulose is to prevent dirt from reattaching by adsorbing dirt particles and fabric surfaces. If the molecular chains are hydrolyzed and broken, their adsorption capacity and steric hindrance effect weaken, making it difficult to effectively disperse dirt during washing. This results in a decrease in the cleanliness of clothing, and light colored clothing is prone to yellowing and graying.

Thickening and suspension performance: Cellulose is thickened by winding molecular chains to form a network structure. After the molecular weight decreases, the network structure is difficult to form, resulting in insufficient viscosity of washing products and poor stability of the system (such as essence, pigment, and active ingredients in laundry detergent are easy to separate).

Compatibility changes: Hydrolyzed or oxidized cellulose may have reduced compatibility with surfactants, chelating agents, preservatives, and other components in washing products due to changes in functional groups, and may even cause turbidity and precipitation in the system, affecting the appearance and user experience of the product.

4. Microbial contamination (in aqueous systems or when moisture absorption is severe)

ifcelluloseWhen stored, if the moisture content is too high (usually>10%) after moisture absorption and the ambient temperature is suitable (25-35 ℃), it is easy to breed bacteria, mold and other microorganisms. Microorganisms can decompose cellulose molecules, causing products to have odor, mold, and abnormal viscosity fluctuations. This not only leads to performance failure, but may also affect product safety due to excessive microorganisms, causing skin risks such as redness and itching after contact with sensitive skin.

2、 Key factors affecting performance changes

Temperature and humidity: High temperature (>35 ℃) accelerates hydrolysis, oxidation, and microbial growth, while high humidity (relative humidity>60%) causes moisture absorption, agglomeration, and hydrolysis, which are the core factors leading to performance changes;

Packaging sealing: Poor sealing can lead to moisture infiltration, oxygen contact, and the introduction of dust and impurities (such as acidic/alkaline substances, oxidative components), accelerating performance degradation;

Impurity contact: When stored, if mixed with acidic/alkaline raw materials, bleaching agents, metal ions (such as iron ions, calcium ions), etc., it will catalyze the hydrolysis or oxidation reaction of cellulose, shortening its stability period;

Light exposure: Long term exposure to sunlight (especially ultraviolet radiation) can damage the molecular structure of cellulose and accelerate oxidative degradation, so it needs to be stored away from light.

3、 Summary

celluloseDuring the storage process of washing and daily chemical products, performance changes mainly include "moisture absorption agglomeration, hydrolysis oxidation, and functional degradation". Improper storage (high temperature and humidity, poor sealing, and contact with impurities) can significantly accelerate these changes, leading to a decrease in product effectiveness, stability, and even safety hazards. Therefore, it is necessary to strictly control the environment during storage: keep it cool and dry (temperature 5-30 ℃, relative humidity ≤ 60%), seal the packaging (to avoid moisture and oxygen invasion), store it in the dark, store it separately (not mixed with acidic, alkaline, or oxidizing substances), and control the storage period (generally recommended not to exceed 12-24 months, subject to the product manual) in order to preserve its original performance to the greatest extent.