High molecular weight polymethyl

Figure 8. DRI and viscometer chromatograms for a high molecular weight polymethyl methacrylate sample.

In Fig. 5.11 some results of Tsvetkov and Budtov (192) are reproduced. These results were obtained on narrow fractions of polymethyl methacrylate of rather high molecular weights. These molecular weights are given in the caption to the figure. 

The pigmentation of Polymethyl Methacrylate (PMMA) and ultrahigh-molecu-lar-weight polyolefins presents familiar difficulties. Due to the high difference in viscosity between the pigment concentrate and these polymers, it is sometimes necessary to use special masterbatches based on high-molecular-weight carriers. 

Copolymerisation reactions do not always succeed in the presence of phenols. Cardanol, converted to the acrylate (R = H) by reaction with acryloyl chloride, has been co-polymerised in the presence of benzoyl peroxide with methyl methacrylate leading to a product vrith improved thermal stability compared with polymethyl methacrylate alone (ref. 265). In a similar way an acrylate and a methacrylate (R = Me) have been synthesised from 3-pentadecylphenol. Polymerisation yielded moderately high molecular weight compounds of potential interest as pressure-sensitive adhesives (ref. 266). 

It has been demonstrated that chemical structure directly affects cooperativity. " To simplify the research, one amorphous polymer with a high molecular weight was chosen. Polymethyl methacrylate (PMMA) was purchased from Aldrich in the powder form. Gel permeation chromatography showed a Mw of 101,300 g/mol with a polydispersity of 1.967. 

The wear behaviour of polytetrafluoroethylene (PTFE), carbon-filled PTFE, high density polyethylene (HDPE), ultrahigh molecular weight polyethylene (UHMPE), low density polyethylene (LDPE) and polymethyl methacrylate (PMMA) was studied. To ensure consistent and controlled properties of the samples, many of the materials were processed in the authors laboratory. The details of sample preparation and processing techniques are reported elsewhere ( ). ... 

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