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MAH Content (mah + content)

Distribution by Scientific Domains
Polymers and Materials Science100%

Selected Abstracts

Grafting of maleic anhydride onto linear polyethylene: A Monte Carlo study

JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 22 2004
Yutian Zhu
Abstract Monte Carlo simulation was used to study the graft of maleic anhydride (MAH) onto linear polyethylene (PE-g-MAH) initiated by dicumyl peroxide (DCP). Simulation results revealed that major MAH monomers attached onto PE chains as branched graft at higher MAH content. However, at extremely low MAH content, the fraction of bridged graft was very close to that of branched graft. This conclusion was somewhat different from the conventional viewpoint, namely, the fraction of bridged graft was always much lower than that of branched graft under any condition. Moreover, the results indicated that the grafting degree increased almost linearly to MAH and DCP concentrations. On the other hand, it was found that the amount of grafted MAH dropped sharply with increasing the length of grafted MAH, indicating that MAH monomers were mainly attached onto the PE chain as single MAH groups or very short oligomers. With respect to the crosslink of PE, the results showed that the fraction of PE-(MAH)n -PE crosslink structure increased continuously, and hence the fraction of PE-PE crosslink decreased with increasing MAH concentration. Finally, quantitative relationship among number average molecular weight of the PE, MAH, and DCP contents was given. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5714,5724, 2004 [source]

Functionalization of high density polyethylene with maleic anhydride in the melt state through ultrasonic initiation

POLYMER ENGINEERING & SCIENCE, Issue 4 2003
Yuncan Zhang
Grafting of maleic anhydride (MAH) onto high density polyethylene (HDPE) performed in the melt state through ultrasonic initiation by a laboratory-scale ultrasonic extrusion reactor was studied in this paper. The effect of sonic intesity on the amount of grafted MAH, viscosity-average molecular weight and melt flow index of the grafted product was investigated. The results show that the ultrasonic waves can obviously decrease the molecular weight of the grafted product and cause the increase of the amount of grated MAH, implying that the grafting reaction consists of the chain scission and the grafting reaction of the produced macroradicals with MAH. The percentage of grafting of the product amounts to 0.6%; its melt-flow index is between 0.5 and 2.0 g/10 min, depending upon ultrasonic intensity, MAH content and grafting temperature. Compared with the method of peroxide initiation, in this method the crosslinking reaction can be prevented easily through the allocation of ultrasonic intensity. The mechanical properties of the improved HDPE/GF composite produced by ultrasonic initiatives are higher than in those produced by peroxide initiatives. [source]

Synthesis of styrene,maleic anhydride random copolymer and its compatibilization to poly(2,6-dimethyl-1,4-phenylene ether)/brominated epoxy resin

POLYMER INTERNATIONAL, Issue 6 2003
Guozheng Liang
Abstract Styrene,maleic anhydride random copolymer (R-SMA7.5), with a low content of maleic anhydride (MAH) of about 7.5 mol%, has been prepared, and the copolymer was characterized by fourier-transform infrared (FTIR) and 13C NMR techniques showing that the product contained only random copolymer without blocks. The miscibility between poly(2,6-dimethyl-1,4-phenylene ether) (PPE) and R-SMA, was investigated by differential scanning calorimetry (DSC), showing that PPE was miscible with R-SMA synthesized in our laboratory over the entire composition with low MAH content. A blend of R-SMA18 (MAH content is about 18 mol%) and PPE was also studied by DSC, which showed that PPE was immiscible when R-SMA was the major component, although it was miscible with limited composition. FTIR investigation showed that R-SMA could react with bromide epoxy (BEP) resin at high temperature (180°). The heat-resistance and mechanical properties of R-SMA/PPE/BEP systems were tested and analyzed, and results indicated that R-SMA could improve the miscibility of PPE and BEP with increasing Tg of the BEP phase and decreasing the Tg of the PPE slightly, improving the breaking elongation and breaking energy, which resulted from good miscibility between PPE and BEP with R-SMA as the compatibilizer. Finally, the properties of the composites (copper clad laminate) with R-SMA7.5 are studied and discussed. Copyright © 2003 Society of Chemical Industry [source]