Deproteinized natural rubber film forming polymeric solutions for nicotine transdermal delivery

2012 ◽  
Vol 18 (5) ◽  
pp. 1111-1121 ◽  
Author(s):  
Wiwat Pichayakorn ◽  
Jirapornchai Suksaeree ◽  
Prapaporn Boonme ◽  
Thanaporn Amnuaikit ◽  
Wirach Taweepreda ◽  
...  
Keyword(s):  
Natural Rubber ◽  
Transdermal Delivery ◽  
Film Forming ◽  
Polymeric Solutions ◽  
Rubber Film ◽  
Deproteinized Natural Rubber

Deproteinized natural rubber film reinforced with silane-modified silica nanoparticles

2020 ◽  
pp. 009524431990036
Author(s):  
Supat Moolsin ◽  
Piwat Prasoppol ◽  
Pichamon Potisuya ◽  
Ratree Seesook
Keyword(s):  
Natural Rubber ◽  
Chemical Method ◽  
Tensile Force ◽  
Rubber Matrix ◽  
Modified Silica ◽  
Elongation At Break ◽  
Modified Silica Nanoparticles ◽  
Rubber Film ◽  
Deproteinized Natural Rubber ◽  
Scanning Electron

Mechanical properties and morphology of the deproteinized natural rubber (NR) films reinforced with modified silica (SiO2) nanoparticles were studied in this research. In the step of deproteinization, a chemical method followed by centrifugation was used to reduce the amount of protein from 0.42 wt% to 0.11 wt%. Structure-modified nanosilica with Silane A174 was used as an additive to reinforce the deproteinized films. The addition of 1 phr of the modified nanosilica exhibited better tensile strength, tensile force at break, modulus at 500% and elongation at break which were improved significantly compared to those of bare films. The modified nanosilica dispersed uniformly in the rubber matrix with the nanoparticle size less than 100 nm observed from the scanning electron microscope. The prepared rubber films containing the modified SiO2 nanoparticles have great potential to produce the NR gloves having very tiny amounts of protein for medical use which still provide the good mechanical strength compared to the standard ones.

Properties of Deproteinized Natural Rubber Latex/Gelatinized Starch Blended Films

2015 ◽  
Vol 659 ◽  
pp. 45-49 ◽  
Author(s):  
Rungtiwa Waiprib ◽  
Wiwat Pichayakorn ◽  
Prapaporn Boonme ◽  
Wirach Taweepreda ◽  
Jirapornchai Suksaeree
Keyword(s):  
Natural Rubber ◽  
Transdermal Delivery ◽  
Natural Rubber Latex ◽  
Homogeneous Mixture ◽  
Rubber Latex ◽  
Viscous Liquids ◽  
Transdermal Patches ◽  
Gelatinized Starch ◽  
Homogeneous Film ◽  
Deproteinized Natural Rubber

This research aimed to study the compatibility and properties of deproteinized natural rubber latex (DNRL)/gelatinized starch blended films for use as transdermal patches. Various starches were previously gelatinized by heat treatment. Then, the DNRL/gelatinized starch blended films were prepared by simple mixing of DNRL with gelatinized starch and then drying at 50°C. The various parameters such as types (potato, sago, bean, corn, tapioca, rice and glutinous starches), amounts (5, 10, 15 and 20 part per hundred of rubber (phr)) and concentrations of gelatinized starch pastes (5, 10, 20 and 50%) were evaluated. It was found that all starch types could be blended as a homogeneous mixture with DNRL only in 5 phr. Bean starch also provided the good mixture in 10 and 15 phr. Rice and corn starches in the concentrations up to 20 phr could also be blended. Higher concentration of gelatinized starch pastes obtained the higher viscous liquids that were difficult to blend as a homogeneous mixture with DNRL, and provided inhomogeneous blended films. The dried films of all homogeneous DNRL/gelatinized starch mixtures were slightly yellowish transparent with good physical appearances. The tensile strength, swelling and erosion of these blended films increased when increasing amounts of gelatinized starch, but their elasticities were not different comparing to that of DNRL film itself. However, their strengths should be further improved by adding some plasticizers. Some drugs would be further loaded in these homogeneous film formulations for transdermal delivery.

Novel membranes from physico-chemically modified deproteinized natural rubber latex: development, characterisation and drug permeation

2018 ◽  
Vol 42 (17) ◽  
pp. 14179-14187
Author(s):  
Janisha Jayadevan ◽  
G. Unnikrishnan
Keyword(s):  
Drug Release ◽  
Natural Rubber ◽  
Natural Rubber Latex ◽  
Rubber Latex ◽  
Drug Permeation ◽  
Chemically Modified ◽  
Blend Membranes ◽  
Deproteinized Natural Rubber

Novel blend membranes from physico-chemically modified deproteinized natural rubber latex for drug release applications.

Ozonation of unstretched natural rubber film fromHevea brasiliensis studied by ozone consumption and13C NMR

2004 ◽  
Vol 53 (6) ◽  
pp. 733-739 ◽  
Author(s):  
FHA Rodrigues ◽  
EF Santos ◽  
JPA Feitosa ◽  
NMPS Ricardo ◽  
F Heatley
Keyword(s):  
Natural Rubber ◽  
Rubber Film

Long-Chain Branching and Mechanism Controlling Molecular Weight in Hevea Rubber

1999 ◽  
Vol 72 (4) ◽  
pp. 712-720 ◽  
Author(s):  
Jitladda Tangpakdee Sakdapipanich ◽  
Tippawan Kowitteerawut ◽  
Krisda Suchiva ◽  
Yasuyuki Tanaka
Keyword(s):  
Molecular Weight ◽  
Natural Rubber ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Branch Points ◽  
Long Chain Branching ◽  
Linear Character ◽  
Close Relationship ◽  
Deproteinized Natural Rubber ◽  
Long Chain

Abstract The linear character of transesterified deproteinized natural rubber (DPNR-TE) was confirmed by the analysis of terminal groups with NMR and viscometric analyses. The branch content of DPNR rubber from fresh latex was found to range from 0.3 to 1.3 and 0.7 to 3.2, based on tri- and tetra-functionalities, respectively. The plot between the number of branch-points and molecular weight (MW) can be divided into three fractions: (A) the rubber fractions in MW ranging from 2.4×105 to 1.9×106; (B) between 1.9×105 and 2.4×105; and (C) those of MW less than 1.9×105. The fraction (A) showed the number of branch-points per a branched molecule (m) higher than that of fractions (B) and (C). This plot is superimposable with the bimodal molecular-weight distribution (MWD) of Hevea rubber, showing a good coinciding of peak-tops at the high and low MW fractions. It seems likely that there is a close relationship between the number of branch-point and bimodal MWD of natural rubber.

Thermal and Thermo-Oxidative Degradations of Deproteinized Natural Rubber and Natural Rubber

2011 ◽  
Vol 306-307 ◽  
pp. 50-57 ◽  
Author(s):  
Can Zhong He ◽  
Zheng Peng ◽  
Jie Ping Zhong ◽  
Shuang Quan Liao ◽  
Xiao Dong She ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Natural Rubber ◽  
Oxidative Stability ◽  
Natural Rubber Latex ◽  
Oxidative Degradation ◽  
Decomposition Reaction ◽  
Nitrogen Atmosphere ◽  
Degradation Temperature ◽  
Air Atmosphere ◽  
Deproteinized Natural Rubber

Deproteinization of natural rubber was achieved in the latex stage. The structure of deproteinized natural rubber (DPNR) was characterized by fourier transform infrared spectroscopy (FTIR). The thermo degradation of DPNR was studied by thermogravimetry analysis (TG) under air atmosphere and nitrogen atmosphere. The kinetic parameters apparent activation energies (Ea) of the thermal decomposition reaction been calculated from the TG curves using the method described by Broido. And the results were compared with the thermo degradation of natural rubber (NR) under the same conditions. The effect of proteins in natural rubber latex on thermal/ thermo-oxidative stability of NR was discussed. The results show that: the absorptions of the proteins in DPNR at 1546 ㎝-1, compared to NR, become significantly weaker, nearly disappear, which indicates most of proteins has been removed from NR. The thermo degradation of DPNR in nitrogen atmosphere is a one-step reaction. The initial degradation temperature (T0) 、the maximum degradation temperature（Tp） and the final degradation temperature（Tf）as well as the Ea of DPNR are higher than those of NR, which indicates that DPNR represents a better thermal stability than NR under nitrogen atmosphere. Thermo-oxidative degradation of DPNR and NR are two-step reaction. The characteristic temperatures (T0, Tp and Tf) of DPNR are lower than those of NR. The Ea during the First Step of Thermooxidative Degradation of DPNR are also lower than those of NR. These results prove that the thermo-oxidative stability of DPNR is worse than that of NR. Protein is the key role to the thermal stability of natural rubber.

PROTEIN INFLUENCE ON THE MECHANICAL PROPERTIES OF NR

2021 ◽  
Author(s):  
Yayoi Akahori ◽  
Misao Hiza ◽  
Soki Yamaguchi ◽  
Seiichi Kawahara
Keyword(s):  
Mechanical Properties ◽  
Nmr Spectroscopy ◽  
Sodium Dodecyl Sulfate ◽  
Carbon Black ◽  
Natural Rubber ◽  
Hevea Brasiliensis ◽  
Sodium Dodecyl ◽  
Swelling Degree ◽  
Deproteinized Natural Rubber ◽  
Rubber State

ABSTRACT Protein effect on vulcanization of NR, obtained from Hevea brasiliensis, was investigated by analyzing the crosslinking structure of the resulting vulcanizates prepared from untreated NR, deproteinized natural rubber (DPNR), and protein-free natural rubber (PFNR) by swelling methods and rubber-state NMR spectroscopy. The proteins present in NR were removed by three methods: deproteinization with enzyme, urea, or urea–acetone in the presence of sodium dodecyl sulfate. The amount of proteins present in NR, approximately 0.238 w/w%, was reduced to 0.000 w/w% by urea–acetone deproteinization, whereas it was reduced to approximately 0.003 and 0.019 w/w% by enzyme and urea deproteinizations, respectively. Hardness, swelling degree, and crosslinking structure depended on the amount of proteins. Changes in mechanical properties for the vulcanizates prepared from not only non-filler compounds but also carbon black–filled and silica-filled compounds were attributed to the amount of proteins.

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