Telechelic liquid natural rubber: A review

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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Thermal Properties and Crystallisation Behaviour of Thermoplastic Natural Rubber (TPNR) Nanocomposites

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.812.125 ◽

2013 ◽

Vol 812 ◽

pp. 125-130 ◽

Cited By ~ 1

Author(s):

Siti Norasmah Surip ◽

Z.Y. Zhang ◽

H.N. Dhakal ◽

N.N. Bonnia ◽

S. H. Ahmad

Keyword(s):

Thermal Properties ◽

Natural Rubber ◽

Nucleating Agent ◽

Preparation Technique ◽

Preparation Methods ◽

Blending Method ◽

Liquid Natural Rubber ◽

Tan Δ ◽

Thermoplastic Natural Rubber ◽

Internal Mixer

The effect of preparation technique on the crystallisation behavior and thermal properties of TPNR filled nanoclay nanocomposites was investigated. The nanocomposites were prepared via melt blending method using internal mixer (Haake 600P). Two types of nanocomposites preparation technique were employed which is method A and B. In method A, the nanoclay was pre-mixed with liquid natural rubber (LNR) before it was charged into the other materials. For method B, the nanoclay was directly charged into the molten TPNR matrix. The result shows, preparation methods were significantly affect the crystallinity and thermal properties of TPNR nanocomposites. DSC thermogram revealed that nanocomposites crystallinity was increased when prepared by method A but decreased with method B. An increment in polypropylene crystallinity was attributed by the nanoclay which is believed to be as a nucleating agent. DMA thermogram suggested that the preparation method has affected the storage modulus and tan δ but not the glass transition temperature (tg).

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

Applied Environmental Materials Science for Sustainability - Advances in Environmental Engineering and Green Technologies ◽

10.4018/978-1-5225-1971-3.ch006 ◽

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.

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