The High-Performance Fluid Loss Reducer & Viscosifier for Water-Based Drilling Fluids: Hydroxypropyl Starch (HPS, CAS# 9049-76-7)

Hydroxypropyl Starch (CAS# 9049-76-7), commonly known as HPS or starch 2-hydroxypropyl ether, is a non-ionic modified starch derivative produced by reacting natural starch (derived from corn, tapioca, potato, or wheat) with propylene oxide under alkaline conditions. Its molecular structure consists of a starch polymer backbone with hydroxypropyl groups (–CH₂–CH(OH)–CH₃) introduced onto the hydroxyl groups via ether linkages. This chemical modification disrupts the crystalline structure of native starch, significantly enhancing its solubility, stability, and functional performance.

As a white to off-white free-flowing powder, HPS disperses readily in cold water without clumping and forms a transparent to translucent viscous colloid upon heating to 60–80°C (gelatinization temperature ~60°C, significantly lower than native starch at ~80°C). The product is supplied in various grades—including oil drilling grade, construction grade, and industrial grade—with packaging options ranging from 25 kg multi-ply paper bags to 600 kg big bags.

Hydroxypropyl Starch is one of the most widely used modified starches in the petroleum industry, serving as a highly effective fluid loss control additive and rheology modifier for water-based drilling fluids. Its non-ionic nature ensures that its performance is only slightly affected by salinity, water hardness, and pH variations, making it highly effective in seawater, brine, and high-salinity drilling environments. Based on its chemical characteristics and industrial significance, this article systematically analyzes the key properties, core application areas, global market structure, regulatory landscape, and future outlook of this strategically important drilling fluid additive.

Core Application Fields and Demand

Market demand for Hydroxypropyl Starch (CAS# 9049-76-7) is concentrated in three primary sectors: oil and gas drilling fluids (approximately 60–65% of global consumption), construction materials and dry-mix mortars (approximately 20–25%), and food, pharmaceutical, textile, and papermaking applications (approximately 10–15%). Its multifunctional performance as a fluid loss reducer, viscosifier, and rheology modifier serves as the core driver of sustained demand growth across all sectors.

In oil and gas drilling fluids, Hydroxypropyl Starch is primarily used for fluid-loss control in drilling muds, drill-in, completion, and workover fluids. When added to water-based drilling fluids, HPS hydrates and swells, forming a structured polymer network through hydrogen bonding and polymer entanglement. This network, combined with fine solid particles, creates a thin, low-permeability filter cake on the wellbore wall, reducing filtrate loss into permeable formations and stabilizing the borehole. HPS also functions as a rheology modifier, providing stability and viscosity control under high-temperature conditions. The non-ionic nature of HPS ensures that its performance is only slightly affected by salinity and hardness in fluids, making it ideal for harsh downhole conditions including saturated brine slurries and calcium-rich environments. Optimal performance in drilling fluid formulations has been achieved using 0.57% m/v of HPS as a filtrate controller. HPS also stabilizes the wellbore, improves borehole conditions, prevents collapse, and flocculates drill cuttings. As a fluid loss reducer for saturated brine slurries, it minimizes water loss, stabilizes the wellbore, and prevents collapses.

In construction materials, HPS is widely used as a thickening agent and rheology modifier in dry-mix mortars, tile adhesives, wall putties, plasters, and EIFS systems. It improves sag resistance, surface smoothness, workability, and open time.

In other industrial applications, HPS serves as an emulsifier, thickener, binder, and stabilizer in foods (E1440), as a disintegrant for tablets in pharmaceuticals, as a warp sizing agent in textiles, and as an internal and surface sizing agent in papermaking.

Key Properties and Product Specifications

Hydroxypropyl Starch (CAS# 9049-76-7) is a non-ionic starch ether whose value derives from its exceptional fluid loss control, rheology modification, and thermal stability properties.

Key physicochemical parameters include:

• CAS Number: 9049-76-7
• EINECS Number: 618-565-2
• Molecular Formula: C₃₁H₅₆O₂₂
• Appearance: White to off-white free-flowing powder
• Hydroxypropyl Content: 15.0%–25.0%
• pH (5% solution): 8.0–10.5
• Viscosity (5% solution, 20°C): 500–2000 mPa·s (customizable)
• Moisture/Loss on Drying: ≤10.0%
• Ash Content: ≤3.0%
• Fineness (80 mesh pass): ≥95%
• Solubility: Soluble in cold water
• Stability: Resistant to enzymatic degradation
• Gelatinization Temperature: ~60°C (native starch ~80°C)
• Thermal Stability: Maintains viscosity at 90–120°C
• pH Tolerance: Stable across pH 3–11
• Freeze-Thaw Stability: ≥5 cycles without syneresis
• Viscosity Loss Under High Shear: ≤15%

The compound’s reactivity is defined by its non-ionic nature and the introduction of hydroxypropyl groups, which disrupt the crystalline structure of native starch, enhancing cold water solubility, reducing retrogradation, improving freeze-thaw stability, increasing enzymatic resistance, and providing superior thermal and shear stability. The hydroxypropyl groups also render HPS more resistant to thermal degradation and bacterial attack.

Major Market Participants

The global supply system for Hydroxypropyl Starch (CAS# 9049-76-7) features a pattern of “specialized starch ether manufacturers, multinational chemical distributors, and Chinese producers dominating large-scale production.” The global drilling starch market, which includes hydroxypropyl starch as a key product type, was valued at approximately USD 1,864.7 million in 2024 and is projected to reach USD 3,500 million by 2035. The market is characterized by a diverse range of product types, including native starch, modified starch, cross-linked starch, and hydroxypropyl starch.

In the global industrial and large-scale production segment, Chinese manufacturers have emerged as a dominant force in the global supply chain. XinChem is a leading manufacturer and supplier of high-purity Hydroxypropyl Starch from China, specializing in premium HPS products widely used in oil and gas drilling fluids, construction materials, and industrial applications. The company offers Hydroxypropyl Starch in multiple grades—including oil drilling grade, construction grade, and industrial grade—with tailored viscosity and substitution degree to meet specific application requirements. Custom synthesis and contract manufacturing with flexible scaling from R&D to commercial tons are available upon request. XinChem provides the compound with stringent quality standards, including comprehensive COA/TDS/SDS documentation for bulk supply.

In the global research and specialty segment, suppliers such as Ataman Kimya and Industrochem offer Hydroxypropyl Starch for construction and oilfield applications, serving the drilling fluids and industrial materials markets.

Regional Market Dynamics

The global Hydroxypropyl Starch market exhibits distinct regional characteristics, with production concentrated in Asia-Pacific (particularly China) and consumption distributed across North America, Europe, and the Asia-Pacific region, aligned with the oil and gas, construction, and industrial manufacturing industries in these regions. The drilling starch market is forecast to grow from USD 974.7 million in 2025 to USD 3,500 million by 2035.

The Asia-Pacific region is the dominant force in the global Hydroxypropyl Starch market, accounting for the largest share of both production and consumption. China serves as the world’s manufacturing hub, with extensive production capacities and integrated supply chains for modified starch products. Chinese manufacturers, including XinChem, offer the compound in multiple grades and viscosity ranges—from 500 to 2000 mPa·s—serving both domestic and export markets with competitive pricing. The rapid growth of oil and gas exploration, construction, and industrial manufacturing in China, India, and Southeast Asia continues to drive regional consumption growth.

North America remains a key market for high-performance Hydroxypropyl Starch, driven by demand from the oil and gas industry, particularly in shale gas extraction and drilling operations. The United States hosts numerous drilling fluid service companies and oilfield operators that require high-quality HPS for fluid loss control and rheology modification. The region’s well-established regulatory framework and emphasis on product quality support demand for high-grade drilling fluid additives.

Europe is characterized by stringent regulatory requirements, including REACH registration, and a strong focus on sustainability and environmental safety in oilfield and construction applications. European drilling fluid service companies and construction material manufacturers demand high-purity HPS with comprehensive documentation.

Latin America, the Middle East, and Africa represent growing markets, with demand driven by expanding oil and gas exploration activities, mining operations, and infrastructure development.

Regulatory and Safety Considerations

As a widely used drilling fluid additive, construction material ingredient, and food additive, Hydroxypropyl Starch (CAS# 9049-76-7) is subject to regulatory oversight in major global economies. Compliance with relevant regulations is essential for market access and trade.

Regulatory compliance: In the European Union, HPS must comply with REACH registration requirements. In the United States, HPS is regulated under TSCA and must meet applicable standards for use in oilfield, construction, and food applications. The compound is listed as a food additive with E number E1440.

Health and safety considerations: Hydroxypropyl Starch is considered to have low acute toxicity and is generally recognized as safe for its intended uses. Standard industrial hygiene practices should be followed during handling, including the use of appropriate personal protective equipment when handling large quantities. The compound should be stored in a cool, dry place in tightly closed containers, protected from moisture.

Environmental considerations: HPS is derived from natural starch sources and is biodegradable. However, as with all industrial chemicals, responsible handling and disposal practices should be followed. The development of environmentally friendly drilling fluid additives is gaining momentum as the industry aims to reduce its environmental footprint.

Future Outlook

The market outlook for Hydroxypropyl Starch is positive, supported by several key growth drivers across its major application segments. The global drilling starch market, which includes HPS, is projected to grow from USD 974.7 million in 2025 to USD 3,500 million by 2035. The drilling starch market size was valued at 1,864.7 USD Million in 2024.

Key growth drivers include:

1. Expansion of oil and gas drilling activities: Increasing global energy demand and the continued development of unconventional oil and gas resources, including shale gas and tight oil, drive demand for high-performance drilling fluid additives like HPS.
2. Growth in offshore and deepwater drilling: The expansion of offshore and deepwater drilling operations, which require high-performance drilling fluids with excellent fluid loss control and rheological properties, supports demand for HPS.
3. Increasing focus on environmental sustainability: Growing environmental concerns and stricter regulations are driving the adoption of biodegradable and environmentally friendly drilling fluid additives, positioning HPS as a preferred choice over synthetic polymers.
4. Expansion of construction and infrastructure development: The rapid growth of construction and infrastructure projects in emerging economies drives demand for HPS in dry-mix mortars, tile adhesives, and other construction materials.
5. Growth in enhanced oil recovery (EOR) applications: HPS has shown promise as a viscosifying agent for enhanced oil recovery fluids, with studies demonstrating additional mineral oil recovery of 12.19% in simulated core flooding tests.

Challenges and considerations:

• Raw material price volatility: Fluctuations in the prices of starch and propylene oxide may impact production costs.
• Competition from synthetic polymers: The market faces competition from synthetic fluid loss control additives and viscosifiers that may offer superior performance in certain high-temperature applications.
• Thermal stability limitations: While HPS offers improved thermal stability over native starch, it may still face limitations in ultra-high-temperature drilling environments, requiring further modification or blending with other additives.
• Regulatory compliance: Increasingly stringent environmental and chemical regulations may require ongoing investment in quality systems and documentation.

To succeed in this evolving market landscape, suppliers must focus on product quality (particularly viscosity consistency, hydroxypropyl content, and thermal stability), supply chain reliability, regulatory compliance, and responsive customer service. Companies that can offer high-purity products in multiple grades, flexible packaging options, and technical support for drilling fluid, construction, and industrial applications will be well-positioned to capture growing demand.

Shanghai XinChem Co., Ltd. (XinChem)

As a world-leading supplier of organic chemicals and drilling fluid additives, Shanghai XinChem Co., Ltd. (XinChem) is dedicated to meeting the innovative needs of the oil and gas, construction, and industrial manufacturing industries. Leveraging extensive experience and advanced manufacturing capabilities, XinChem provides high-quality Hydroxypropyl Starch (HPS, CAS# 9049-76-7) to customers worldwide. As a trusted manufacturer and supplier based in China, XinChem combines competitive pricing, reliable supply, and exceptional service to establish itself as a preferred partner for drilling fluid service companies, construction material manufacturers, and industrial customers seeking this versatile non-ionic starch ether.

1. Technical Advantages

Advanced Etherification and Quality Control
XinChem utilizes state-of-the-art manufacturing facilities and rigorous quality control measures to ensure the purity, consistency, and safety of its Hydroxypropyl Starch products. The production process incorporates advanced etherification technology—reacting natural starch with propylene oxide under controlled alkaline conditions to introduce hydroxypropyl groups onto the starch polymer backbone. This modification enhances cold water solubility, reduces retrogradation, improves freeze-thaw stability, increases enzymatic resistance, and provides superior thermal and shear stability. XinChem offers Hydroxypropyl Starch in multiple grades—Oil Drilling Grade, Construction Grade, and Industrial Grade—with tailored viscosity (500–2000 mPa·s) and substitution degree to meet diverse application requirements. Strict process control ensures consistent product quality, minimal impurities, and batch-to-batch reproducibility, providing customers with reliable performance in drilling fluid formulations, construction materials, and industrial applications.

Full-Chain Quality Control
The production process strictly adheres to international quality standards, with comprehensive quality control covering raw material sourcing, in-process monitoring, and finished product testing. Each batch is accompanied by a detailed Certificate of Analysis (COA) documenting physical and chemical properties, hydroxypropyl content, viscosity, pH, moisture content, ash content, fineness, and impurity profiles. This commitment to quality ensures that XinChem’s Hydroxypropyl Starch meets the stringent requirements of oil and gas drilling, construction, and industrial applications.

2. Product Advantages

High Performance and Consistent Quality
XinChem offers Hydroxypropyl Starch with hydroxypropyl content of 15.0%–25.0%, viscosity of 500–2000 mPa·s (customizable), pH of 8.0–10.5, moisture ≤10.0%, ash ≤3.0%, and fineness ≥95% (80 mesh pass). The product’s high performance and consistent quality minimize the risk of variability, making it suitable for demanding applications in oil and gas drilling fluids, construction materials, and industrial processes.

Comprehensive Specifications
Key specifications include:

• CAS Number: 9049-76-7
• EINECS Number: 618-565-2
• Molecular Formula: C₃₁H₅₆O₂₂
• Appearance: White to off-white free-flowing powder
• Hydroxypropyl Content: 15.0%–25.0%
• Viscosity (5% solution, 20°C): 500–2000 mPa·s (customizable)
• pH (5% solution): 8.0–10.5
• Moisture/Loss on Drying: ≤10.0%
• Ash Content: ≤3.0%
• Fineness (80 mesh pass): ≥95%
• Solubility: Soluble in cold water
• Grades: Oil Drilling Grade, Construction Grade, Industrial Grade

Flexible Packaging Solutions
XinChem provides a range of packaging options to accommodate diverse customer needs, from laboratory-scale quantities to industrial-scale multi-ply paper bags (25 kg with PE liner) and big bags (600 kg). Customized packaging solutions are available upon request, ensuring safe handling, storage, and transportation. Recommended storage conditions include storage in a cool, dry place in tightly closed containers, protected from moisture.

3. Application Fields

As a multifunctional non-ionic starch ether, Hydroxypropyl Starch (CAS# 9049-76-7) exhibits wide application value across multiple industries:

Oil and Gas Drilling Fluids:

• High-performance fluid loss control additive for water-based drilling muds
• Rheology modifier providing viscosity control and stability under high-temperature conditions
• Forms thin, low-permeability filter cake on the wellbore wall
• Stabilizes wellbore, prevents collapse, and flocculates drill cuttings
• Effective in seawater, brine, and high-salinity drilling environments
• Used in drill-in, completion, and workover fluids
• Minimizes water loss and prevents collapses in saturated brine slurries

Construction Materials:

• Thickening agent and rheology modifier in dry-mix mortars, tile adhesives, and wall putties
• Improves sag resistance, workability, and open time

Food Industry:

• Emulsifier, thickener, binder, and stabilizer (E1440)

Pharmaceutical Industry:

• Disintegrant for tablets

Textile Industry:

• Warp sizing agent improving abrasion resistance

Papermaking Industry:

• Internal and surface sizing agent

4. Service Support

Technical Expertise and Customized Solutions
XinChem’s team of experienced polymer chemists and application engineers provides full technical support throughout the customer journey—from product selection and specification development to application guidance and troubleshooting. Whether customers require optimization of drilling fluid formulations, guidance on HPS selection for specific applications, or assistance with regulatory documentation, XinChem’s technical experts are ready to help. Custom synthesis and contract manufacturing with flexible scaling from R&D to commercial tons are available upon request.

Global Logistics and Reliable Supply
With established supply chains serving markets across Europe, North America, Asia-Pacific, and beyond, XinChem ensures timely delivery and consistent product availability. The company’s logistics team manages all aspects of international shipping, including customs clearance and documentation.

Regulatory Support
XinChem provides comprehensive documentation to support regulatory compliance, including Safety Data Sheets (SDS), Certificates of Analysis (COA), and other required certificates. The company stays current with evolving regulatory requirements in major markets, including REACH, TSCA, and other regional regulations, helping customers navigate the complexities of global trade.

5. Reasons to Choose XinChem

• Professionalism: Extensive experience and deep expertise in starch ether manufacturing and supply.
• Quality: Rigorous quality control, consistent product quality, and adherence to international standards.
• Reliability: Stable supply, competitive pricing, and timely delivery.
• Flexibility: Customized solutions to meet diverse customer needs, including multiple grades and tailored viscosity.
• Service: Responsive technical support and comprehensive documentation including COA/TDS/SDS.

Contact us today to start your partnership with XinChem!

Website: www.xinchem.com

Email: sales1@xinchem.com

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