Reactive extrusion of TPE-E nanocomposites Case Study

Reactive extrusion of TPE-E nanocomposites - Case Study Example It is very difficult to do extrusion blending with TPEE because it has a low melt viscosity and tension. Its melt viscosity and tension can be increased by adding branching agent during polymerization. Even with this increase, it is not sufficient to perform extrusion blowing. There are several attempts, which have been made to increase melt viscosity and tension during extrusion by use of a chain extender during melt polymerization. Reduction of crystallization time through reactive extrusion of PBT with the use of diepoxy group as a chain extender provides a simpler method of getting high molecular weight of PBT than the conventional method of poly-condensation. Researchers acknowledge that multifunctional polymers such as TMP, TME and trimesic acid can be used to produce high molecular weight of PET. There is an effect of the modified m-MDI in the blending process of PET since the increase of m-MDI increases the molecular weight of PET. However the reaction should not be abled to continue for a long time and m-MDI should not be added because there will be crosslinking of the product because of the excessive reaction of isocyanate. This will later affect the ductility of the blend. In a situation where the correct amount of m-MDI is used then the molecular weight of PET is reduced with increasing time of blending. This is because of degradation hydrolytic and isocyanate group. It is very important to complete the process within a short time to avoid degradation. If the time is not enough to complete the process of forming urethane then there will be production of carbon dioxide by unreacted isocyanate groups at the stage of post extrusion. fluoromica pristine clay modified with alkyl-ammoniums (ODTMA) Moreover, the unreacted group of isocyanate might result into undesirable side reaction at the post processing stage (Brown & Alder, Pp 35). Hence, it is very important to ensure that the process is completed and the physical properties are maintained. The best processing parameters for blending m-MDI and TPEE must be found. The current thermoplastic polyester elastomer (TPE) is characterized by qualities such as excellent heat resistance, resistant to light, heat-aging resistance, and good in block order retaining ability and low temperature traits. The TPE is made up of hard section, which consists of polyester, which comprises of aromatic dicarboxylic acid and aliphatic or alicyclic diol, and a soft section, which consists of aliphatic polycarbonate as the main ingredient. Through which where the hard and soft section becomes connected, and the melting points of the TPE are arrived at by taking their measurements using a differential scanning calorimeter in three stages. First temperature is raised from room temperature to 3000 C, at a 200 C/min heating rate, then for three minutes maintain temperatures at 3000 C after which lower it to room temperature at a cooling rate of 1000 C/min. (Tm1 – Tm3) obtains the melting point differ ence (Brown, Alder, 65). Materials pTMEG, 1,4-BD, Irganox 1010 and modifies m-MDI, MM103C. In addition, poly (butylene terephthalate) was also used. In addition phenol, together with 1, 1, 2, 2-tetrachloroethane, CF3COOD and TBT were used without any purification. The inner viscosity of the polymer was determined by use ubbelohde viscometer at 35 degrees (Chang, Pp 54). Usually IV is

Regeneration Essay Example | Topics and Well Written Essays - 1000 words

Regeneration - Essay Example four major criteria which included, ‘increasing the demand for local labour’, ‘reducing local labour-market imperfections, ‘increasing mobility and awareness of job opportunities’, and ‘increasing the skills of local residents through educational or training schemes’. Correspondingly, the LDDC policies formulated by the central government can be identified to promote the gentrification process (Church, 1987). Similarly, the study of Butler and Lees (2006) asserted the prevalence of super-gentrification in ‘inner London neighbourhood of Barnsbury’, which was further in line with the gentrification noticed in New York. Notably, the Abercrombie Plan visualized â€Å"the outward movement of London’s population to locations beyond the Green Belt at the cost of a declining inner city population† (Keddie, n.d.). These examples can be viewed as evidences which suggest that London Planning Policy promotes the gentrificati on process. 5 The term ‘gentrification’ is one of the most widely debated subject matters in the domain of urban planning. It depicts the transformations in urban design with regard to changes in lifestyle values or economic situations of any particular urban region. The process primarily depicts the idea of providing an increasing share of urban area for wealthier people in order to ensure maximum development of a particular area (Syrett & Sepulved, 2010; (Roberts & Sykes, 2000). This essay will answer the question, as to whether planning policy in London aims to promote or prevent gentrification Gentrification in London has resulted in the emergence of widespread challenges. Gentrification in London is argued to have several negative impacts on the lives of urban population. Notably, gentrification is criticised on several grounds. For example, it has been claimed that gentrification results in ‘loss of affordable housing’, ‘under-occupancy and population loss to gentrified areas’, ‘displacement through rent/price