Poly tetramethyl carbonate

Observations Polycaprolactone and poly(tetramethyl carbonate) are biodegradable poly-... 

PS-PMMA Poly(styrene-co- acrylonitrile), PS, PMMA, poly(cyclohexyI methacrylate), polycarbonate or poly(tetramethyl carbonate) (Lowenhaupt er al. 1994)... 

The degradation of poly-oc-esters was studied on poly(isopropylidine carboxylate) [518] over a range of temperatures, from 200 to 800°C. Among the decomposition products were found tetramethyl glacolide, acetone carbon monoxide, and to a lesser extent methacrylic acid. The primary decomposition product appears to be tetramethylene glacolide that becomes an intermediate upon further pyrolysis ... 

Lastly, before leaving polymer blends, attention is drawn to the possibility of the interaction parameter % being dependent on Q, the scattering vector, as well as the composition of the polymer mixture. Evidence for this behaviour has been given by Brereton et al. [34] for the mixture of deuteropolystyrene with poly(tetramethyl carbonate) (PTMC). The reciprocal scattering as a function of for different temperatures was not a series of parallel lines of data. 

The case of amorphous poly(ethylene terephthalate) (PET), where there are no side groups, is considered in Section 10.3.2 in conjunction with semi-crystalline forms of this polymer. Worthy of mention is the use of antiplasticisers to show that the p relaxation is composite [8,9]. In studies of bisphenol A (and tetramethyl bisphenol A), polycarbonate intramolecular cooperativity associated with the carbonate residue was shown by the introduction of the methyl groups on the phenyl rings [10], and intermolecular cooperativity was shown by the dielectric behaviour of blends [11]. Further evidence for intermolecular contributions to the ring motions was obtained from the observed pressure dependence of the proton NMR transverse relaxation time [12]. There is a key conclusion for polymers... 

The miscibility profile of aliphatic polyesters is similar (not surprising) to poly(e-caprolac-tone). The phase behavior of cellulose acetate proprionate (CAP) with ahphatic polyesters based on C2 to C8 straight chain diols with glutaric acid was investigated by Buchanan et al. [224]. Miscibility was observed with C2 to C6 diols and partial miscibility with the C8 diol based aliphatic polyesters. Although CAP is typically amorphous (unblended), crystallization was observed by plasticization of the lower Tg polyesters. The crystallization rate of the aliphatic polyesters was suppressed by addition of CAP. Aliphatic polyesters with CH2/COO ratios of 2 to 5 have been shown to be miscible with Bisphenol A polycarbonate (PC) [225] and miscible with tetramethyl Bisphenol A polycarbonate (TMPC) with CH2/COO ratios of 5 to 10 [226]. Aliphatic polyesters also showed a miscibility window with phenoxy (PHE) with the volume fraction of the aliphatic carbon in the polyester of between 0.7 and 0.9 [227]. 

Nishida H, Andou Y, Watanabe K, Arazoe Y, Ide S, Shirai Y (2011) Poly(tetramethyl glycolide) from renewable carbon, a racemization-free and controlled depolymerizable polyester. Macromolecules 44 12-13... 

Rather than being carbon-based, the backbone chain can also be composed of silicon atoms, again together with other elements. The last two materials, poly(dimethylsiloxan) and poly(tetramethyl-p-silphenylene-siloxane) are corresponding examples. 

Figure 10 Correlation between polymer density and helium permeability P through polyethylene at 25 °C 1, poly(tetra-methyl-bis-L terephthalate) (1) 2, poly(tetraisopropyl-bis-A sulfone) (2) 3, poly(2,6-dimethyl-1,4-phenylene oxide) (3) 4, poly(tetramethylcyclobutanediol carbonate) (4) 5, poly(tetramethyl-bis-A carbonate) (5) 6, poly(tetramethyl-bis-L sulfone) (6) 7, poly(tetramethyl-bis-A terephthalate) (7) 8, poly(tetramethyl-bis-A sulfone) (8) 9, poly(bis-A carbonate) (9) 10, poly(bis-...

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