Alternative water soluble polymeric films to poly(vinyl alcohol) for single unit dose products
- Autores: Jie Ma
- Directores de la Tesis: José Antonio Reina Lozano (dir. tes.), Florence Courchay (codir. tes.)
- Lectura: En la Universitat Rovira i Virgili ( España ) en 2020
- Idioma: español
- Tribunal Calificador de la Tesis: Pierfrancesco Cerruti (presid.), Alberto Vaca Puga (secret.), Adrianna Nogalska (voc.)
- Programa de doctorado: Programa de Doctorado en Nanociencia, Materiales e Ingeniería Química por la Universidad Rovira i Virgili
- Materias:
- Enlaces
- Tesis en acceso abierto en: TDX
- Resumen
Laundry detergent pod is a water-soluble pouch that contains highly concentrated laundry detergent, currently the pouch is made of Poly(vinyl alcohol) (PVA). As business continues to grow P&G would like to find some other materials able to replace PVA film. The objective of this PhD project is to look for alternative materials for SUD film, which would have similar detergent compatibility, water solubility, permeability and mechanical properties as PVA film. Additionally, we would like to discover whether the new material would bring new benefits.
In this thesis, films made of polyetheylen glycol (PEG), sodium alginate, Lactips material, sodium caseinate (NaCAS), as well as their blends with PVA were prepared, properties of those films were tested, and pouching prototypes of some of the films were prepared. Solution casting was selected as the method for preparing the films.
This thesis is composed of 8 chapters. Apart from Chapter 1 (General introduction and objectives), Chapter 2 (Materials and test methods), and Chapter 8 (General conclusions and future work), Chapter 3 describes PEG-based films and their properties; Chapter 4 describes sodium alginate-based films and their properties; Chapter 5 describes Lactips material-based films, as well as their properties; Chapter 6 describes pouch prototyping with Lactips film and discusses pouch stability; Chapter 7 describes sodium caseinate-based films and their properties.
The conclusion of this research are summarized as follows: • The preparation and characterization of PEG film, PVA film, as well as PEG/PVA blended films were carried out, optimizing the procedure to the system in terms of blending ratio and the wet-gap when casting using manual casting knife.
• The dissolution times of the PEG film, PVA film and PEG/PVA blended film were studied, without noticing big differences: PEG film and blended film dissolve as fast as PVA film.
• PEG film exhibits less tensile strength and tensile strain compared to PVA film, by blending with PVA the tensile strength was improved, and by blending with plasticizer, the maximum elongation was increased.
• PEG film presents low melting point, which was increased by reaction with glutaraldehyde, albeit not significantly sufficient to justify further efforts within SUD context.
• Sodium alginate film and its blends with PVA and/or PEG were prepared and characterized.
• The dissolution times of sodium alginate film and the blends are acceptable, though a bit slower than virgin PVA film.
• The stiffness of sodium alginate film is very high, which was not decreased by blending with PVA and/or PEG.
• The preparation and characterization of Lactips film and its blends with PVA were carried out, the procedure of preparation was optimized in terms of blending ratio and the wet gap of manual casting knife.
• Lactips film is not compatible with current detergent in SUD, by blending with PVA the compatibility improved, but not significantly enough.
• The dissolution times of Lactips film and its blending with PVA are acceptable, though a bit slower than PVA film. The LAC/PVA blended films rupture slower than that of virgin PVA and Lactips films, due to hydrogen bonding between Lactips and PVA chains.
• The tensile strength and strain of Lactips film are not as high as PVA film, by blending the two materials together, better tensile strength and strain were achieved, and both parameters increased with more proportions of PVA.
• Glycerol was selected as plasticizer for the LAC/PVA blended film, which increased film elongation at break and decreased film stiffness.
• Lactips and LAC/PVA blended films present a bit lower water vapor barrier property as PVA film.
• Lactips commercial film can be successfully converted into pouches in both lab and pilot plant scale, it is possible to be processed in a continuous operation.
• Lactips film behaves good when used to pack powder detergent, thus can be applied in auto dish washing pouch applications.
• Lactips film is sensitive to water, less water amount in the detergent can improve the film-detergent compatibility, and further investigation is still needed to have stable Lactips liquid pouch.
• Lactips film has advantage over PVA film in clay-removal in a laundry appliance.
• The preparation and characterization of Lactips film and its blends with PVA were carried out, the procedure of preparation was optimized in terms of blending ratio and the wet gap of manual casting knife. Glycerol was selected as plasticizer.
• The dissolution times of NaCAS and NaCAS/PVA blended films are faster than PVA, after 10 min immersion in water, NaCAS film totally dissolved, more than 2 times than PVA film. The NaCAS/PVA blended films rupture slower than virgin NaCAS and PVA films due to hydrogen bonding.
• NaCAS film is very brittle. The tensile strength and strain of NaCAS are significantly improved when blended with PVA.
• NaCAS film and NaCAS/PVA blended films have similar water vapor barrier property as PVA film.
