The aim of this work was to evaluate the influence of the use of coupling agent (CA) on the properties of thermoplastic composites produced from post-consumer polypropylene (rPP) and malt bagasse fibers (MB) of brewing industry. The CA used was maleic anhydride graft polypropylene copolymer (MAgPP). The study was carried out in two stages: in first step the best concentration of MB fibers was verified, where was varied the fiber contents between 0, 10, 20 and 30% (w/w); in the second step, the best MB concentration evaluated was used with different CA concentrations (0, 1, 3, 5 and 7% w/w). Of the three MB concentrations evaluated as reinforcing filler, the sample with a 30% (w/w) ratio presented 44% lower deformation than the others, presenting better mechanical resistance, although it also presented the highest water absorption. Thus, the 30% MB fiber content was chosen for two step, where the results showed that the PP/MB-30 composite treated with 3% (w/w) CA had a modulus of elasticity 10.3% higher than the same composite without CA, corroborating with the morphological analysis, which indicated better interfacial adhesion between composite components when CA was used. The PP/MB-30 composite treated with 1% (w/w) CA showed the highest thermal stability among all samples.
Polyurethanes 93 -Abstracts tion, and equipment modifications when compared to non-combustion modified foams.A recently developed ARCO Chemical Company polyol technology has been shown to minimize and/or overcome the negative aspects of using solid flame retardant additives such as melamine. For example, foams have been produced with this new technology which do not require any melamine to pass BS 5852 Part 2, Source 5 and the amount of melamine filler required for foam/fabric &dquo;mock-up&dquo; composites to pass the California TB 133 standard has been reduced by up to 100%.* In this paper, the performance of this new generation of polyols will be demonstrated by a number of bench-made as well as pilot production formulations.The polyurethane foam industry is extremely involved in the challenge of improving behavior to fire of its products and from the beginning has put a great deal of R&D efforts to satisfy the legislation requirements while preserving inherent peculiarities of the products. In the case of flexible foams a major impulse was given in the recent past by the use of standard melamine or graphite based formulations also containing high levels of phosphohalogenated flame retardant additives. In such a way, most severe fire tests are being successfully passed. However, some drawbacks very often negatively affect this approach due, i.e., to losses in some foam properties (especially the compression set and dynamic fatigue values). Trying to overcome these detrimental aspects EniChem Polyurethane Division is introducing a set of solutions, specifically designed for the different fire ratings required by various existing and likely to be new legislation. First of all, a polyol containing a low level (corresponding to approx. 10 pbw in the formulation) of a new melamine type is proposed that, when used in a normal CMHR formulation, gives foams passing the British Standard test crib 5 at minimum level of halogenated additives (3-5 pbw), without penalizing foam properties down to 23 kg/m3 density and with much improved processability. Foams produced with the addition of the above mentioned polyol without use of halogenated compounds were rated as class 1.IM according to the Italian test CSE-RF4.Moreover, an alternative route has also been traced thanks to the employment of a modified TDI (Tedimon 173) that allows production of flexible foams passing the Italian test CSE-RF4 Class 3.IM and the Match & Cigarette test (ISO 8191-2 and ISO 8191-1), without any addition of flame retardant additives. *This numerical flame spread rating is not intended to reflect hazards presented by this or any other material under actual fire conditions.
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