Characterization of ethylene/propylene copolymers by means of a GPC-4D technique

Electrochemical synthesis of novel conductive polymer and corrosion protection properties on aluminium

“…[47][48][49][50][51] The GPC results for the PPy and copolymer samples are given in Table 2. After y10 injections, the adsorption sites had become saturated, and full recovery was achieved.…”

Polymer chain conformation of copolymers with different monomer size: 13C NMR spectroscopy and MALS study

“…Ethylene/1-hexene (EH) and ethylene/4-methyl-1-pentene (EMP) 13 C NMR spectra were acquired on a Bruker AVANCE 400 spectrometer, equipped with a SEX 10 mm probe with automatic matching and tuning, operating at 100.58 MHz, 103°C, 14.30 ls as 90°pulse; 32 K data points, acquisition time 2.14 s, relaxation delay 18 s, 3 K transients. Proton broad band decoupling was achieved using bi_walz16_32 power-gated decoupling.…”

“…In order to avoid such influence, the above scaling law can be modified to describe R g against the number of monomer units in the chain (n). Thus, the new scaling law is [13]:…”

“…This behavior was also previously observed for ethylene-propylene copolymers obtained from different catalytic system. Heterogeneous comonomer distribution increases the probability to get a random coil conformation, but also the q values increase with molecular weight, and both variables have to be considered [13].…”

Application of the correct design of successive self-nucleation and annealing (SSA) to study the stereo-defects and its distribution of homo- and co-polypropylene

“…13,[16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34] For PP samples, with the increase of separation temperature, the component separated by TREF showed higher melting temperature and longer isotactic sequence length aer SSA treatment, and 13 C-NMR result also indicated that the isotacticity of polypropylene and isotactic sequence length of PP increased. 27,[35][36][37][38] Compared with 13 C-NMR and TREF fractionation, SSA fractionation was a more time-saving and practical technique in the characterization of the molecular structure of PP, as well as a way providing important quantitative information about the lamellar thickness and its distribution of PP, which gave a more accurate characterization to the isotactic sequence length and its distribution of polypropylene.…”