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How are agar and algin obtained for use as natural adhesives?
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adhesive
Overview of how glue and other adhesives work.
Agar and algin are natural colloids derived from seaweed that function as adhesives, primarily in water-remoistenable products. They are obtained through the following processes:1
- Agar: This gelatin-like product is extracted from red algae (such as Gelidium and Gracilaria) using hot water. Following extraction, the product is typically frozen to facilitate purification.21
- Algin: This substance is derived from brown seaweeds. It is obtained by digesting the seaweed in an alkali solution, after which it is precipitated as either alginic acid or its salt (alginate).3415
Both substances are valued for their colloidal properties, which allow them to act as effective binding or thickening agents in various commercial applications.134