![]() Moreover, LNR with a molecular weight below 20,000 g/mol is an attractive material for enhancement of further modifications. Adding LNR to the blends improved the interaction between the phase of the blends, and they concluded that the LNR content added to the blends marginally affected the physical properties of NR/LLDPE blends. The ultraviolet irradiation technique was used to prepare LNR. observed the effects of various molecular weights of LNR as a compatibilizer on the physical properties of NR/LLDPE blends. LNR was used as a compatibilizer in NR/LLDPE (linear low-density polyethylene) blends. This reaction was carried out through photocatalytic decomposition of H 2O 2 when exposed to UV light, with or without a TiO 2 film mounted on the quartz substrate. synthesized the deproteinized LNR with hydroxyl end groups by the photochemical reaction. LNR containing hydroxyl and carbonyl end groups was observed, resulting from chain breaking. The NR chains were attacked by radicals at carbon–carbon single bond or oxidation at carbon–carbon double bond by oxygen species. prepared the degraded NR latex under UV light in the presence of H 2O 2 and nano TiO 2, which was prepared via the sol–gel method. Mechanical degradation of NR through mastication in the air at high temperatures is usually done before processing to facilitate easy processing or incorporation of other chemicals. The molecular weight of NR can be reduced by different methods such as mechanical, chemical, photochemical, ozonolysis, or thermal degradation in a dry, solution, or latex state. LNR produced from the degradation of NR latex is related to breaking the NR chain either by direct scission of the carbon–carbon single or carbon–carbon double bonds of the polyisoprene backbone. It becomes a modified NR, allowing greater flexibility in the production of the NR used. The NR can be degraded to liquid natural rubber (LNR), which has a similar microstructure to NR and consists of shorter polymeric chains and lower molecular weight (M w < 10 5). NR latex is known as a diene rubber in its repeating units of cis-1,4-isoprene, with the molecular weight varying greatly, from only a few hundred thousand to more than one million. Natural rubber (NR) is an important renewable biopolymer in many industries due to its elastic property and excellent mechanical strength. The LNR containing functional end groups exhibited thermal instability and could be a starting material for many applications. ![]() Based on TGA analysis, the thermal stability of the rubber depended on its M n. In addition, the pre-exponential factor and activation energy were 1.04 × 10 9 M −1.72 t −1 and 78.66 kJ/mol, respectively. The experimental results showed the reaction orders of, , and were 1.58, 0.79, and −0.65, respectively. SEM micrographs showed the latex particles of LNR were spherical and smaller compared to NR. FTIR spectra indicated the synthesized LNR contained hydroxyl end groups resulting from the breaking of the NR chains at an acidic pH, whereas a carboxyl terminated LNR was formed at an alkaline pH. Prolonged reaction time and high temperature resulted in a product with low M n. However, a higher concentration of NaNO 2 decreased the M n reduction. ![]() Results showed the higher concentration of H 2O 2 and HCOOH employed faster degradative rates. The influence of reagent concentrations, temperature, and reaction time on the number-average molecular weight (M n) was studied. Liquid natural rubber (LNR), a depolymerized natural rubber (NR) consisting of shorter chains, was prepared via oxidative degradation using NaNO 2 and H 2O 2 degrading agents in the presence of HCOOH. ![]()
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