Effect of NCO/OH ratio on physical and mechanical properties of castor-based polyurethane grouting materials

Abstract

This research focused on fabrication of castor-based PU grout (CPUG) using castor oil with OH value of 161 mg/KOH/g and MDI with NCO content of 31%. The effect of different NCO/OH ratio on the foam reaction time, density, rheology, morphological and mechanical properties were investigated. The result shows that the rise time of CPUG decreased while tack free time increased with the increased of NCO/OH ratio. Morphological properties shows that CPUG consist of closed cell of foams and the diameter of a single cell foam decreased with the increased of NCO/OH ratio. The apparent density, rheology index, flexural strength, flexural modulus and compression strength of CPUG increased with the increasing NCO/OH ratio. CPUG’s apparent density was in the range of 230.23 kg/m3 while rheology index of CPUG was between 1.74 to 2.43 cm/g. Both values obtained were in the range of industrial PU grout’s density and rheology index (214 kg/m3 & 1.48 cm/g). CPUG4 give the best flexural and compression strength with a value of 11.01Mpa and 2Mpa respectively. Flexural and compression strength of CPUG were tantamount to the industrial PU grout’s properties which the average of flexural strength and compression strength were about 7.4MPa and 2MPa respectively.

Porous‐structured vermiculite/polybutylene adipate terephthalate composite films: The morphology, mechanical properties, and nonisothermal degradation kinetics

“…In Equation ( 2), α is the mass degradation rate, β is the heating rate, and T is the temperature value corresponding to different heating rates β under the same degree of decomposition. The advantage of the FWO method is that it does not assume the reaction mechanism, and the activation energy E can also to determine by linear relationship obtained from graph of ln β versus 1 T p . The biggest difference between the FWO method and the K-method lies in that the K-method is designed for kinetic parameter analysis under the maximum degradation rate, and the kinetic parameters only involve the peak temperature during calculation, which may lead to large results.…”

“…As the global population continues to increase, people's dependence on fossil resources has caused a strain on fossil resources, which has led to attention being paid to this problem. [1][2][3][4][5] At the same time, the ecological environment has also been polluted by the large amount of waste discharged every day, especially the ecological pollution caused by plastic waste is particularly serious. [6][7][8][9][10][11] In recent years, countries have begun to fully implement the "plastic ban", which makes biodegradable materials in the use of disposable tableware, packaging, agriculture and other aspects of the development opportunities.…”

Preparation of Castor-Based Polyurethane Composites Filled With Waste Carbon Tyres (Wct) as Grouting Material

“…Castor-based polyurethane composites (CPUC) were prepared by adding waste carbon tyres (WCT) into neat castor-based polyurethane with NCO:OH ratio of 2.6:1 [11]. Table 1 shows the formulation of CPUC.…”

Polyurethane grouting materials with different compositions for the treatment of mud pumping in ballastless track subgrade beds: properties and application effect

“…Polyurethane grouting is widely applied in highways, housing construction, and underground engineering. Polyurethane grouting materials have been investigated experimentally and/or theoretically from many aspects, including material synthesis and modification [21][22][23], mechanical and macroscopic properties [24][25][26][27][28], the evolution mechanism of macro-mechanical properties and microstructure characteristics [29][30][31][32], and the diffusion mechanism and expansion characteristics of polymer grout [33][34][35][36][37]. However, existing studies have mainly focused on the engineering backgrounds of water conservation, structure lifting, and foundation treatment and reinforcement.…”