Water soluble polymer-based mechanical properties

However, the mechanism of action of filtration control additives is not yet completely understood. Examples are bentonite, latex, various organic polymers, and copolymers. Many additives for fluid loss are water-soluble polymers. Vinyl sulfonate fluid loss additives based on the 2-acrylamido-2-methyl-propane sulfonic acid (AMPS) monomer are in common use in field cementing operations [363]. The copolymerization of AMPS with conjugate monomers yields a fluid loss agent whose properties include minimal retardation, salt tolerance, high efficiency, thermal stability, and excellent solids support. 

The same group has also obtained composite materials based on imogolite and water-soluble polymers such as hydroxypropylcellulose (HPC) and poly (vinylalcohol) (PVA) [32]. HPC is a rigid rod polymer that has a cholesteric phase, whereas PVA is a random coil amorphous polymer. Significantly enhanced mechanical properties were only obtained in the case of the HPC composite materials. 

Considerable research has been conducted to identify water soluble polymers which can efficiently control the flow properties of displacement fluids for enhanced oil recovery.Two main types of polymeric viscosifiers have emerged from this research which rely mainly on ultra high molecular weight for thickening efficiency natural biopolymers such as Xanthan or Scleroglucain and synthetic acrylamide based polymers. Although these polymers possess many useful characteristics, the reservoir conditions in which they can provide adequate mobility control are limited. For example, the biopolymers provide excellent mechanical stability and salt tolerance, however, further improvement in high temperature stability would be desirable. 

PNC have been prepared with virtually all polymers, from water-soluble macromolecules to polyolefins and high-temperature specialty resins such as polyimide (PI). Elastomer-based PNCs with large clay platelets have been commercialized for improved barrier properties in automotive tires or sport balls. Elastomeric epoxy resins with clays demonstrate substantial improvement in mechanical properties (e.g., tensile modulus and strength) [Varghese and Karger-Kocsis, 2005 Utracki, 2008]. In this chapter we focus primarily on clay-containing PNCs, the CPNCs. 

Natural polymers such as starch and protein are potential alternatives to petroleum-based polymers for a number of applications. Unfortunately, their high solubility in water limit their use for water sensitive applications. To solve this problem thermoplastic starches have been laminated using water-resistant, biodegradable polymers. For example, polylactic acid and P(3HB-co-3HV) were utilised as the outer layers of the stratified polyester/PWS (plasticized wheat starch)/polyester film strucmre in order to improve the mechanical properties and water resistance of PWS which made it useful for food packaging and disposable articles [65]. Moreover, improved physic-chemical interactions between P(3HB-CO-3HV) and wheat straw fibres were achieved with high temperature treatment. It resulted in increased P(3HB-co-3HV) crystallization, increased Young s moduli and lowered values of stress and strain to break than the neat matrix of P(3HB-co-3HV). There was no difference in the biodegradation rate of the polymer [66]. 

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