MAPP treatment

The assignment of complex carbonyl absorption peaks in the IR spectra of oxidized samples has been considerably eased by the derivatization techniques. It is noted that MAPP treatment in the BFPP composites has shown that the shoulder on the carbonyl band at 1780 cm results from the formation of y-lactones. The absorption maximum at 1735 cm is postulated to result either from the carbonyl groups of esters or from the carbonyl vibration of carboxylic... 

Silane treatment normally does not damage the natural fibers because fiberdamaging elements such as an acidic catalyst are not present in the silane solution nor is high temperature treatment used, as mentioned above. Therefore, it is noted that the tensile strength of natural fibers should be little affected by the silane itself [36]. MAPP treatment may slightly increase the fiber strength due to the deposition of MAPP copolymer on the fiber surfaces, leading to more or less uniform and smooth surfaces [86]... 

Since the actual structures of the pores of the insoluble polymer supports used as gel permeation chromatography resins are not known, an exact theoretical treatment of the technique is not possible, and the gel permeation characteristics of a solute can only be compared in a relative fashion. (In alluding to molecular weights determined by this method, we shall use the term Mapp since values obtained by this method are approximate.) All estimates of polymer dimensions based on gel chromatography are therefore relative and based on those determined for polymers whose dimensions are known. 

The isotactic polypropylene (iPP) was supplied by FiberVisions, Georgia, in the form of homopolymer pellets with a melt flow index of 35g/10 min (230 °C, 160 g) and a density of 0.91 g cm-3. The reinforcing filler was rice straw fibril and fibril aggregates (RSF) obtained from rice straw pulp fiber (Taonan paper and pulp company, Jihn ptrovinoe. North-east of China) that was cut to pass a screen (room temperature and relative humidity of 30%) with holes of 1 mm in diameter by a Willey mill before treatment. The maleated polypropylene (MAPP) was used as compatibilizing agent and Epolene G-3003 P has an acid number of 6 and a molecular mass of 125 722. 

Figure 19.8 Reaction mechanism involved during the treatment of cellulose fibres with PP maleic anhydride copolymer (MAPP) (a) activation of MAPP (T = 170°C) before fibre treatment and (b) esterification of cellulose.

The treatment of cellulose fibers with hot polypropylene-maleic anhydride (MAPP) copolymers provides covalent bonds across the interface (Han et al. 1991). There are two ways of obtaining biocomposites from namral fibers and polymer. In the first one, pretreated fibers with maleated polymer are reinforced with desired polymer matrix. 

Flax fibers are stronger, crisper, and stiffer to handle, and more easily wrinkled due to their crystalline nature. Flax fibers are about 12-16 pm in diameter. Effect of various treatments such as maleic anhydride (MAH), maleic anhydride-PP copolymer (MAPP), and vinyl trimethoxy silane (VTMOS) have been studied on flax fibers (natural flax and flax pulp) and PP composites. These composites were characterized by FTIR to study the effect of treatment and by dynamic contact angle (long fibers) and capillary rise (pulp) to determine the surface energy values. All these three treatments reduced the polar component of the surface energy of the fibers. The composites prepared with MAPP treated PP exhibited highest... 

In order to improve the interfacial adhesion, the addition of functionalized polymers, i.e., MAPP or MAPE to the composite is employed. The presence of these polymers slightly modifies stiffness, but significantly increases tensile yield stress, tensile strength, and in some cases deformabillty [69,70], The numerous other surface modification techniques like silane treatment [71,72], isocyanates [73,74], surfactants [75], and various monomers as well as chemical modification [76,77] are also utilized. 

The aim of this research was to create novel composites for bulk applications using cellulose as reinforcement. We intented to improve properties of polymer composites reinforced with cellulose by pretreating fibers with maleic anhydride modified polypropylene (MAPP). The effect of hydrolytical treatment of cellulose on the dispersibility of fibers in polymers was also investigated. Novel materials based on bacteria-produced polyesters and cellulose were manufactured and their properties evaluated. 

The shape of the HRR curves for the WG-treated samples in Figure 14.9 is typical of samples which show initial increase in HRR until an effective heat barrier is formed. Once this barrier thickens, there is a steady decrease in HRR. This is in contrast to the HRR curve for PP30S which shows a sharp increase in HRR, indicating the fact that the whole sample is pyroUzed at about the same time. The time to reach PHRR was increased by the presence of MAPP. This is in line with the above explanation with respect to sisal/HPP adhesion. On the other hand, the WG-treatment did not improve the time elapsed for the PHRR which was practically identical with that of the reference composite (PP30S). 

The above systems and process would need to be referenced to the MAPP required under COMAH for hydrazine. Effectively, although not all water treatment chemicals would be subject to regulation under COMAH, they will be treated as such in designing and implementing pollution prevention measures. This approach will also be in full accordance with that outlined in the Environmental Permitting (EP) guidance (Reference 14.6). 

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