Inorganic-Organic Composite Materials from Liquid Natural Rubber and Epoxidised Natural Rubber Derivatives

2017 ◽  
pp. 128-140
Author(s):  
Wan Ahmad Kamil Mahmood ◽  
Mohammad Hossein Azarian
Keyword(s):  
Composite Materials ◽  
Natural Rubber ◽  
Sol Gel ◽  
Polymeric Materials ◽  
Metal Alkoxides ◽  
Inorganic Glass ◽  
Transparent Films ◽  
Polymer Component ◽  
Liquid Natural Rubber ◽  
Preparation Techniques

Organic-Inorganic composite materials (OICs) are used to describe the group of materials synthesized from polymers and inorganic metal alkkoxides. The interests in these materials arised from the need to ‘combine' the physical properties of inorganic glass materials and polymers such that the resultant OICs have the strength of the inorganic glass and flexibiliy of polymeric materials. Sol-gel technique have been the technique of choice due to much of its advantages, in particular the low temperature reaction. This is very important when natural rubber and its derivatives are used as the polymer component of the OICs. Work in our laboratory has demonstrated that OICs form liquid natural rubber (LNR) and 50% epoxidised natural rubber (ENR-50) can be prepared from various metal alkoxides, such silicon, zirconium and titanium. The OICs can be prepared as flexible transparent films, nanofibers and nanobeads. This Chapter will describe the preparation techniques and the properties of these OICs from various compositions of one and more metal alkoxides in both LNR and ENR-50. The applications of these materials in PANI will be briefly described.

scholarly journals Preparation and Characterization of Low-Molecular-Weight Natural Rubber Latex via Photodegradation Catalyzed by Nano TiO2

Polymers ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1216 ◽  
Author(s):  
Suhawati Ibrahim ◽  
Nadras Othman ◽  
Srimala Sreekantan ◽  
Kim Tan ◽  
Zairossani Mohd Nor ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Titanium Dioxide ◽  
Natural Rubber ◽  
Chemical Structure ◽  
Sol Gel ◽  
Natural Rubber Latex ◽  
Low Molecular Weight ◽  
Rubber Latex ◽  
Liquid Natural Rubber ◽  
New Applications

Natural rubber is one of the most important renewable biopolymers used in many applications due to its special properties that cannot be easily mimicked by synthetic polymers. To sustain the existence of natural rubber in industries, modifications have been made to its chemical structure from time to time in order to obtain new properties and to enable it to be employed in new applications. The chemical structure of natural rubber can be modified by exposure to ultraviolet light to reduce its molecular weight. Under controlled conditions, the natural rubber chains will be broken by photodegradation to yield low-molecular-weight natural rubber. The aim of this work was to obtain what is known as liquid natural rubber via photodegradation, with titanium dioxide nanocrystals as the catalyst. Titanium dioxide, which was firstly synthesized using the sol–gel method, was confirmed to be in the form of an anatase, with a size of about 10 nm. In this work, the photodegradation was carried out in latex state and yielded low-molecular-weight natural rubber latex of less than 10,000 g/mol. The presence of hydroxyl and carbonyl groups on the liquid natural rubber (LNR) chains was observed, resulting from the breaking of the chains. Scanning electron microscopy of the NR latex particles showed that titanium dioxide nanocrystals were embedded on the latex surface, but then detached during the degradation reaction.

POLYMERS FOR PHOTONICS

1994 ◽  
Vol 03 (04) ◽  
pp. 531-541 ◽  
Author(s):  
P.N. PRASAD
Keyword(s):  
Nonlinear Optical ◽  
Sol Gel ◽  
Polymeric Materials ◽  
Inorganic Glass ◽  
Important Class ◽  
Nonlinear Optical Effect ◽  
New Developments ◽  
Polymeric Systems ◽  
Photorefractive Polymers ◽  
Combined Action

Polymers have emerged as an important class of materials for applications in photon-ics. In this review, a brief background is presented on photonics and nonlinear optical processes, the latter providing many of the operational functions for the photonics technology. Nonlinear optical processes in polymeric materials are discussed along with the needed structural requirements. The three types of nonlinear polymeric systems discussed are: (i) χ(2) materials; (ii) χ(3) materials and (iii) photorefractive polymers. The photorefractive polymeric systems utilize the combined action of photoconductivity and nonlinear optical effect. New developments using sol-gel processed inorganic glass: polymer composites for nonlinear optics are discussed.

Reinforcing efficiency and compatibilizing effect of sol–gel derived in situ silica for natural rubber/chloroprene rubber blends

RSC Advances ◽  
2014 ◽  
Vol 4 (102) ◽  
pp. 58816-58825 ◽  
Author(s):  
Bharat P. Kapgate ◽  
Chayan Das
Keyword(s):  
Natural Rubber ◽  
Sol Gel ◽  
Rubber Blends ◽  
In Situ Silica ◽  
Chloroprene Rubber ◽  
Compatibilizing Effect

The strong CR/in situ silica interaction causes filler accumulation at the interphase and enhances the compatibility and reinforcement in the NR/CR blend.

scholarly journals Nanostructure Analysis of Sol-gel PZT Thin Films Derived from Different Chemical Routes

2009 ◽  
Vol 15 (S3) ◽  
pp. 53-54
Author(s):  
Aiying Wu ◽  
P. M. Vilarinho
Keyword(s):  
Thin Films ◽  
Data Storage ◽  
Chemical Reactivity ◽  
Sol Gel ◽  
Random Access ◽  
Lead Zirconate ◽  
Piezoelectric Response ◽  
Metal Alkoxides ◽  
Pzt Thin Films ◽  
Wide Range

AbstractLead zirconate - lead titanate (PZT) materials are commercially important piezoelectric and ferroelectrics in a wide range of applications, such as data storage (dynamic access and ferroelectric random access memories) and sensing and actuating devices. PZT with the morphotropic phase boundary composition offers the highest piezoelectric response and at the present there are no fullydeveloped alternative materials to PZT. The importance of PZT associated with the continuous requirements of device miniaturization, imposes the development of high quality PZT thin films with optimized properties. Concomitantly due to the dependence of the final properties of thin films on the details of the microstructure a thoroughly analysis at the local scale of their microstructure is necessary. Sol-gel method, is one of the Chemical Solution Deposition techniques used to prepare oxide thin films, such as PZT. Starting from a solution, a solid network is progressively formed via inorganic polymerisation reactions. Most metal alkoxides used for sol-gel synthesis are highly reactive towards hydrolysis and condensation. Therefore their chemical reactivity has to be tailored via the chemical modification (or complexation) of metal alkoxides to avoid uncontrolled reactions and precipitation. For PZT sol gel thin film preparation, two chemical routes are frequently used depending on the nature of the molecular precursor, namely methotoxyethanol (MOE) route and diol-route.

scholarly journals Functionalization of Liquid Natural Rubber via Oxidative Degradation of Natural Rubber

Polymers ◽  
2014 ◽  
Vol 6 (12) ◽  
pp. 2928-2941 ◽  
Author(s):  
Suhawati Ibrahim ◽  
Rusli Daik ◽  
Ibrahim Abdullah
Keyword(s):  
Natural Rubber ◽  
Oxidative Degradation ◽  
Liquid Natural Rubber

Electromechanical-Conductive Natural Rubber Doped Eggshell and Eggshell Membrane for Drug Delivery and Actuator Applications

2018 ◽  
Vol 934 ◽  
pp. 43-49
Author(s):  
Poramin Boonprasert ◽  
Nuchnapa Tangboriboon
Keyword(s):  
Composite Materials ◽  
Natural Rubber ◽  
Artificial Muscle ◽  
Eggshell Membrane ◽  
Curing Time ◽  
Electrical Field ◽  
Fibrous Protein ◽  
Rubber Composite ◽  
Field Response ◽  
Biomimetic Actuator

Natural rubber composite materials were prepared by using sulfur curing system of STR 5L added with hen eggshell and eggshell membrane to increase electrical and mechanical properties for biomimetic actuator and artificial muscle applications. Samples were vulcanized at temperature 150°C. Hen eggshells and eggshell membrane powder (0, 20, 40, and 60 phr) were added into natural rubber. The main composition of hen eggshells composed of 96.35 wt% calcium carbonate (CaCO3) while mostly composition of hen eggshell membrane is fibrous protein in terms of collagen. The best condition is addition of eggshell 40 phr (formula 3) and eggshell membrane 20 phr (formula 5) to obtain the highest storage modulus response equal to 2.85 x 106 and 2.97 x106 Pa, respectively. The curing time (Tc90) of pure natural rubber (formula 1), formula 3, and formula 5 are 8.22, 6.73, and 5.67 min, respectively. Furthermore, the curing time, rheology, and electrical field response of natural rubber composite materials were measured by moving die rheometer and impedance analyzer, and reported here.

Chemical Depolymerisation of Natural Rubber in Biphasic Medium

2014 ◽  
Vol 1024 ◽  
pp. 193-196
Author(s):  
Ibrahim Suhawati ◽  
Asrul Mustafa
Keyword(s):  
Molecular Weight ◽  
Natural Rubber ◽  
Chemical Structure ◽  
Inner Core ◽  
Particle Surface ◽  
Natural Rubber Latex ◽  
Carbonyl Groups ◽  
Latex Particles ◽  
Liquid Natural Rubber ◽  
Biphasic Medium

The molecular weight of natural rubber (NR) can be reduced via depolymerization reaction to produce liquid natural rubber (LNR) with a molecular weight less than 50 000 g/mol. In the reaction, hydrogen peroxide and sodium nitrite were added to natural rubber latex to initiate a redox type reaction which then breaks the NR chain. Low permeation of reagents into latex particles allows the degradation to occur greater at the latex particle surface relative to the inner core contributes to high molecular weight distribution (MWD) or polydispersity of the LNR obtained. In this recent works, the reaction was carried out in a biphasic medium consisting of water and toluene phases. Toluene swells latex particles as indicated by the SEM micrographs showing changes in the size of latex particles. This occurrence is suggested to increase the influx of reagents into the latex particles. Consequently, with higher permeation of reagents into the latex particles resulted in the decrease of molecular weight and lower polydispersity of the LNR obtained. Chemical structure analysize showed that the LNRs obtained were attached with hydroxyl and carbonyl groups.

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