Hydroxypropyl methylcellulose hydrocolloid systems: Effect of hydroxypropy group content on the phase structure, rheological properties and film characteristics

The rheological properties of HTPB mixed with boron (B) or agglomerated boron (TB) were investigated to explore the effect of the impurities of boron on the processing of propellant. The phase structure, morphology, and acidity of each sample were characterized by XRD, SEM and pH, respectively. The results show that rheological property of B/HTPB can be significantly improved by agglomerating boron with binder. Time has little effect on the viscosity of TB/HTPB while that of B/HTPB is a strong function of time. The viscosity of TB/HTPB decreases when the temperature increases from 303K to 343K, while that of B/HTPB decreases from 303K to 323K and then increases sharply after 323K. After agglomerating with binder, theTonsetof boron reduces from 1056K to 954K andTpdrops from 1076K to 998K. Compared with B2, the weight gain and oxidation degree of TB2 increases by 27% and 8.5%, respectively.

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The effect of compatibilization and rheological properties of polystyrene and poly(dimethylsiloxane) on phase structure of polystyrene/poly(dimethylsiloxane) blends

Journal of Polymer Science Part B Polymer Physics ◽

10.1002/polb.10732 ◽

2004 ◽

Vol 42 (5) ◽

pp. 898-913 ◽

Cited By ~ 7

Author(s):

C. Z. Chuai ◽

S. Li ◽

K. Almdal ◽

J. Alstrup ◽

J. Lyngaae-Jørgensen

Keyword(s):

Rheological Properties ◽

Phase Structure

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Hydroxypropyl methylcellulose substituent analysis and rheological properties

Carbohydrate Polymers ◽

10.1016/j.carbpol.2013.05.081 ◽

2013 ◽

Vol 98 (1) ◽

pp. 276-281 ◽

Cited By ~ 26

Author(s):

Hannah Akinosho ◽

Samantha Hawkins ◽

Louise Wicker

Keyword(s):

Rheological Properties ◽

Hydroxypropyl Methylcellulose

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Carboxymethylated pulp as starting point to prepare hydroxypropylmethyl cellulose with enhanced gel rheological properties in an aqueous medium

BioResources ◽

10.15376/biores.16.1.1453-1468 ◽

2021 ◽

Vol 16 (1) ◽

pp. 1453-1468

Author(s):

Othman Hamed ◽

Rana Al-Kerm ◽

Rola Al-Kerm ◽

Hisham Qrareya ◽

Abdalhadi Deghles ◽

...

Keyword(s):

Aqueous Solution ◽

Rheological Properties ◽

Repeat Unit ◽

Hydroxypropyl Methylcellulose ◽

Polymer Chains ◽

Significant Drop ◽

Hydroxypropylmethyl Cellulose ◽

Thermal Gelation ◽

Polymer Precipitation ◽

Starting Point

Hydroxypropyl methylcellulose in an aqueous solution upon heating tends to undergo thermal gelation, where the polymer chains form a network and precipitate from solution. This occurs at a temperature known as thermal gelation point. Polymer precipitation causes a significant drop in the shear viscosity. This could be a disadvantage in a hot environment or in applications were heat is applied. In this work, a hydroxypropylmethyl cellulose (HPMC) was formed that undergoes thermal gelation with no polymer precipitation and with enhanced rheological properties. The target HPMC was prepared from wood pulp with a low content of carboxymethyl groups. The produced hydroxypropyl methylcellulose (CMHPMC) derivative showed unique physical properties that are not achievable with typical hydroxypropyl methylcellulose. The thermal gelation temperature of an aqueous solution of CMHPMC was increased from 55 °C for commercial HPMC to 85 °C for CMHPMC. A substitution level of carboxymethylation that led to an HPMC with a thermal gelation and with no precipitation was determined to be a 0.15 of carboxyl groups per anhydroglucose repeat unit. In addition, the carboxymethylated pulp showed an enhanced reactivity towards etherification reactions.

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Synthesis and characterization of a cysteine xyloglucan conjugate as mucoadhesive polymer

Brazilian Journal of Pharmaceutical Sciences ◽

10.1590/s1984-82502013000200010 ◽

2013 ◽

Vol 49 (2) ◽

pp. 285-292 ◽

Cited By ~ 7

Author(s):

Mangesh Bhalekar ◽

Savita Sonawane ◽

Shamkant Shimpi

Keyword(s):

Rheological Properties ◽

Covalent Attachment ◽

Synthesis And Characterization ◽

Thiol Groups ◽

Chemically Modified ◽

Mucoadhesive Polymer ◽

Disulphide Bonds ◽

Group Content

The aim of this study was to improve the mucoadhesive potential of xyloglucan polymer by the covalent attachment of cysteine as thiol moiety. The parent polymer xyloglucan was chemically modified by introducing sulphydryl bearing compound L-cysteine HCl. Different batches of xyloglucan-cysteine conjugates were prepared at varying reaction pH (2-6) and evaluated for optimum thiol incorporation, disulphide group content, swelling behavior, rheological properties and mucoadhesive properties. The obtained conjugates characterized in vitro by quantification of immobilized thiol groups; showed maximum thiol incorporation on xyloglucan (7.67 ± 0.14 %) at pH 5. The disulphide group content was found maximum (2.83 ± 0.12) at pH 6. The water uptake at end of 4 h was 5.0 for xyloglucan and was found to decrease in thiolated derivatives with increase in thiolation. Mucoadhesion studies revealed that mucoadhesion of xyloglucan-cysteine conjugate increased more than twice compared to the unmodified polymer. The viscosity of thiomer was more than that of xyloglucan because of formation of disulphide bonds.

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