Poly copolymers thermal properties investigation

In the present study, we have investigated the synthesis of OVE from CO2 and GVE in view of the characteristics of phase transfer catalysts and reaction mechanism as well as its application with acylonitrile(AN) to the synthesis of corresponding copolymer. We have tested monomer reaetivity ratio and thermal properties of the copolymer. The blends of poly(OVE-co-AN) and SAN were prepared, and the degree of miscibility was examined by... 

Dynamic mechanical analysis has also been used to determine the mechanical and thermal properties of low-density polyethylene and ethylene-propylene-diene terpolymer containing jute filler, which had improved flexural and impact properties compared to those of the base polymer [198]. Jeong and coworkers [196] and others [195] investigated the dynamic mechanical properties of a series of polyhexamethyl-ene lerephthalale, poly(l,4-cyclohexylenedimethylene terephthalate), and random copolymers thereof in the amorphous state as a function of temperature and frequency. The effect of copolymer composition on dynamic mechanical properties was examined and the dynamic mechanical properties interpreted in terms of the cooperativity of segmental motions. 

The stabilization of poly(vinyl chloride) against light has been reviewed by Wirth and Andreas. Detailed mechanistic studies have indicated the importance of peroxides in the process of photo-oxidation. It was suggested that protection could be successfully achieved by exclusion of radiation of A < 380 nm. E.s.r. examination of irradiated samples demonstrated the intervention of peroxides in the mechanisms with the ultimate formation of carbonyl groups which caused chain scission by Norrish cleavage. Photo-oxidation of samples of poly(vinyl chloride) modified by incorporation of acrylonitrile-butadiene-styrene, methyl methacrylate-butadiene-styrene, and methyl methacrylate-acrylonitrile-butadiene-styrene copolymers has been investigated. Discolouration was accelerated by the presence of the modifiers. Thermal pre-treatment accelerated photo-induced decomposition. Mechanical properties were also examined, and scanning electron microscopy showed surface defects due to decomposition of the modifier. ... 

The thermal properties of poly(AN-co-ATRIF) copolymers were investigated by DSC and by thermogravimetry. The glass transition temperature, Tg, increased from 17°C to 61°C as the mole percentage of ATRIF decreased from 77% to 16% in the copolymer (the molar% F also decreased from 34% to 13% in the copolymer) (Table 20.4). 

A carboxyl-terminated unsaturated polyester was esterified with poly(oxy-ethylene) diols [70]. Using poly(oxyethylene) diol with a munber average molecular weight of 2000, partly crystalline block copolymers were obtained. The unsaturated block copolyether ester contained predominantly one terminal polyether group per molecule. Block unsaturated copolyetheresters with shorter poly(oxyethylene) terminal groups of M = 350 and 550 were also obtained. The effect of the composition of those UPRs on the mechanical and thermal properties was investigated [70]. The block copolyetherester with Mn = 2000 can be dissolved in styrene monomer, thus forming a UPR with acceptable viscosity at as little as 20% styrene. 

Table 17 provides a list of various polysiloxane-poly(aryl ether) copolymers investigated. Depending on the type, nature and the level of the hard blocks incorporated, physical, thermal and mechanical properties of these materials can be varied over a very wide range from that of thermoplastic elastomers to rubber modified engineering thermoplastics. Resultant copolymers are processable by solution techniques and in some cases by melt processing 22,244). 

Elanthikkal et al. investigated the effect of CNCs (from banana waste fibers) (0-10% w/w) on the morphological, thermal, and mechanical properties of poly(ethylene-co-vinyl acetate) (PEVA)/cellulose composites. The produced composites showed superior thermal and mechanical properties as compared to that of the EVA copolymer alone. In this study, three different theoretical models (Halpin-Tsai model, the Kemer model and the Nicolais-Narkis model) have been employed to compare the results with observation of tensile data from mechanical tests. Here, experimental results showed better agreement with the prediction given by the use of the Halpin-Tsai model, assuming that there is perfect wetting of filler by the polymer matrix [217]. 

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