Effect of Polymorphism on the Particle and Compaction Properties of Microcrystalline Cellulose

Rojas, John

doi:10.5772/56591

Cited by 13 publications

(19 citation statements)

References 30 publications

(24 reference statements)

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“…A wide range of elastic moduli values for the CNCs have been reported in literature depending upon the source, methodology for measurement, type of cellulose and its composition 38,39 . The true densities of CNC I and CNC II were considered to be 1.57 and 1.54 g/cc 40 . The true densities of CNC I and CNC II were considered to be 1.57 and 1.54 g/cc 40 .…”

Section: Mechanical Modellingmentioning

confidence: 99%

“…These observations indicate the presence of strong hydrogen bonded interaction between the polymer matrix and the CNC polymorphs. r H/a refers to the specific absorption ratio , which depends upon the strength of hydrogen bonds and should be within the range from 1.2 to 1.75 40 . The IR band at 1830 cm -1 is assigned to hydrogen bonded C=O groups originating from the PLA/CNC based interactions.…”

Section: Structural Properties and Dispersion Characteristics Of Pla/mentioning

confidence: 99%

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Effect of cellulose nanocrystal polymorphs on mechanical, barrier and thermal properties of poly(lactic acid) based bionanocomposites

et al. 2015

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Electronic Supplementary Information (ESI) available: XRD and FTIR spectra of pretreated bamboo pulp, AFM micrographs and height profiles of CNC I, CNC II and CNC: I→II and their properties (Table S1), XRD spectra for different PLA/CNC polymorph films at 1wt% CNC loading. See Cellulose nanocrystals (CNCs) using different polymorphs of cellulose were fabricated from raw bamboo pulp through alkali treatment followed by acid hydrolysis. The effect of CNC polymorphs, namely CNC I, CNC II and CNC:I→II (CNC II from cellulose I), on its morphology, crystal structure, degree of hydrogen bonding and thermal stability were studied. These polymorphs were dispersed in polylactic acid (PLA) films using casting evaporation approach and their effect on the structural, thermal, mechanical and barrier properties of the PLA were investigated. The CNC polymorphs differ significantly in their reinforcement capability and ability to form percolated network. Incorporation of CNC II and CNC: I→II significantly improved the Young's modulus of composites (by ~72%). However, their elongation at break significantly decreased compared to CNC I, due to high hydroxyl functionality, which forms entangled hydrogen bonded network within the polymer matrix, leading to improvement in mechanical as well as barrier properties. The theoretically calculated moduli of composites using Halpin Kardos, Cox-Krenchel and Ouali models showed good agreement for CNC I,CNC II and CNC:I→II respectively, albeit at higher aspect ratio. All three CNCs showed the capability to form percolated network, the occurrence and stability of which varied with the type of polymorphs. Therefore, the current study provides an insight towards selection of appropriate polymorphs for fabrication of CNC reinforced high performance poly (lactic acid) based bionanocomposites.

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Section: Mechanical Modellingmentioning

confidence: 99%

Section: Structural Properties and Dispersion Characteristics Of Pla/mentioning

confidence: 99%

Effect of cellulose nanocrystal polymorphs on mechanical, barrier and thermal properties of poly(lactic acid) based bionanocomposites

et al. 2015

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“…Such crystallographic modification is further confirmed upon spray-drying of theophylline–chitosan complexes [ 110 ]. Theoretically, as the percent relative crystallinity increases, the crushing strength of tablets also increases [ 117 ]. Crystalline regions have a highly ordered arrangement of molecules in their structure.…”

Section: Chitin and Chitosan For Direct Compression Processingmentioning

confidence: 99%

Chitin and Chitosan as Direct Compression Excipients in Pharmaceutical Applications

et al. 2015

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Despite the numerous uses of chitin and chitosan as new functional materials of high potential in various fields, they are still behind several directly compressible excipients already dominating pharmaceutical applications. There are, however, new attempts to exploit chitin and chitosan in co-processing techniques that provide a product with potential to act as a direct compression (DC) excipient. This review outlines the compression properties of chitin and chitosan in the context of DC pharmaceutical applications.

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“…MCC-OPEFB samples also showed the coexistence of both polymorph types I and II. Two shoulders at 2 of 20.4° and 12.5° with their respective lattice planes of 110 and 110 ̅ indicate that acid hydrolysis also contributed in the changes of polymorph type [7,28]. The crystallinity index, CrI (%) of OPEFB, α-cellulose, OPEFB-MCC and CMCC are listed in Table 1.…”

Section: Results and Discussion X-ray Diffractionmentioning

confidence: 99%

Thermal Characteristics of Microcrystalline Cellulose From Oil Palm Biomass

Kuthi

Norzali

Badri³

2016

MJAS

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Extracted cellulose from oil palm empty fruit bunch fiber (OPEFB) was subjected to acid hydrolysis in producing microcrystalline cellulose (MCC). The acid hydrolysis was conducted using 1 % (v/v) sulfuric acid (H 2 SO 4 ) at varying temperatures of 120, 130 and 140 °C for an hour. The relationship between the thermal behavior and physical properties was investigated by thermogravimety (TGA/DTG) and differential scanning calorimetry (DSC) as well as x-ray diffractometry (XRD). The hydrolyzed MCC at 120 °C (MCC A ) showed the highest thermal stability temperature and percentage of crystallinity at 250 °C and 65.07% respectively. However, hydrolyzed MCC at 130 °C (MCC B ) and 140 °C (MCC C ) exhibited low thermal stability temperature at 225 °C and 220 °C respectively. The percentage of crystallinity obtained for MCC B and MCC C was 61.18% and 60.64% respectively. This study revealed that the degree of crystallinity for cellulose has positive impact on the thermal degradation temperature of the OPEFB-MCC.Keywords: acid hydrolysis, microcrystalline cellulose, oil palm empty fruit bunch, thermal behavior Abstrak Selulosa yang diestrak dari serabut tandan kosong sawit (STKS) dihidrolisis menggunakan asid bagi menghasilkan mikrokristal selulosa (MKS). Hidrolisis berasid dijalankan dengan menggunakan 1 % (v/v) asid sulfurik (H 2 SO 4 ) pada suhu yang divariasikan iaitu 120, 130 dan 140 °C selama sejam. Hubungan antara sifat terma dan sifat fizikal dikaji berdasarkan analisis termogravimetri (TGA/DTG), anlisis kalorimetri imbasan kebezaan (DSC) serta kaedah pembelauan sinar-X (XRD). Peningkatan suhu hidrolisis menunjukkan kesan yang kontra terhadap sifat terma STKS-MKS. MKS yang dihidrolisis pada suhu 120 °C (MKS A ) menunjukkan suhu kestabilan terma dan peratus kehabluran yang paling tinggi iaitu masing-masing pada 250 °C dan 65.07%. MKS yang dihdrolisis pada 130 °C (MKS B ) dan 140 °C (MKS C ) mempamerkan suhu kestabilan terma yang rendah iaitu masing masing pada suhu 225 °C dan 220 °C. Peratus kehabluran yang diperoleh bagi MKS B dan MKS C masing-masing adalah 61.18% dan 60.64%. Kajian ini memberi indikasi bahawa darjah kehabluran selulosa memberi kesan positif kepada suhu degradasi terma TKKS-MKS.

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Effect of Polymorphism on the Particle and Compaction Properties of Microcrystalline Cellulose

Cited by 13 publications

References 30 publications

Effect of cellulose nanocrystal polymorphs on mechanical, barrier and thermal properties of poly(lactic acid) based bionanocomposites

Effect of cellulose nanocrystal polymorphs on mechanical, barrier and thermal properties of poly(lactic acid) based bionanocomposites

Chitin and Chitosan as Direct Compression Excipients in Pharmaceutical Applications

Thermal Characteristics of Microcrystalline Cellulose From Oil Palm Biomass

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