Hydrolysed polymaleic anhydride (HPMA), as a versatile polymer, exhibits excellent properties in several areas. The following is a detailed analysis of its performance studies:
I. Basic Properties
- Chemical structure: HPMA is a low molecular weight polyelectrolyte, generally relative molecular weight is 400~800, non-toxic, easily soluble in water, high chemical and thermal stability, decomposition temperature is above 330℃.
- Physical state: usually light yellow to brownish red transparent liquid, relative density is 1.2 (20℃), acidic, can be ionised.
Second, the main performance
- Scale inhibition performance:
- HPMA has excellent scale inhibition performance, which can effectively prevent the formation and deposition of scale (such as calcium carbonate) and improve the operating efficiency of water system. Its scale inhibition rate can reach 98%, and scale inhibition time can reach 100 hours.
- Under high temperature (less than 350℃) and high pH value environment, HPMA can still maintain good scale inhibition and dispersion effect.
High temperature resistance:
- HPMA has high thermal stability and decomposition temperature above 330℃, which is suitable for application in high temperature environment.
Corrosion inhibition effect:
- When HPMA is compounded with zinc salt, it can effectively prevent the corrosion of carbon steel and prolong the service life of the equipment.
Dispersing performance:
- HPMA can also be used as a dispersant to prevent soil particles from settling, break soil crusts and improve soil permeability.
Soil conditioning properties:
- As a soil conditioner, HPMA can regulate soil pH, promote the absorption of fertiliser nutrients by vegetation, and play the role of soil improvement.
Third, application areas
- Water treatment:
- HPMA is often used as water treatment agent for circulating cooling water and low pressure boiler water, as well as oilfield water injection and crude oil dewatering treatment.
- HPMA also performs well in the flash evaporation device for seawater desalination.
Oil extraction:
- As an additive in drilling and completion fluids, HPMA improves drilling efficiency and reduces equipment wear.
Coatings, paper, textiles and pharmaceuticals:
- HPMA is also widely used in these industries as a thickener, dispersant and stabiliser.
Soil Conditioning:
- In the field of agriculture, HPMA acts as a soil conditioner, which helps soil improvement and crop yield increase.
IV.Production process
The production process of HPMA mainly consists of two steps: polymerisation and hydrolysis:
- Polymerisation stage:
- Use initiators (such as peroxides or azo compounds) to control the temperature and time of the reaction to obtain the desired molecular weight of polymaleic anhydride.
Hydrolysis stage:
- Hydrolysis of the polymaleic anhydride is catalysed by acid or base to introduce carboxylic acid groups to form hydrolysed polymaleic anhydride (HPMA).
V. Safety Precautions
- HPMA is an acidic substance, direct contact with skin, eyes, etc. should be avoided. Immediately after contact, flush with plenty of water and seek medical help.
- Appropriate protective equipment, such as protective gloves and overalls, should be worn during operation, storage and transport.
- In case of leakage, personnel should be quickly evacuated to a safe place and isolated.