Abstract:
Butene-1 copolymers containing: a) from 1 to 7 % by mole of ethylene derived units, and b) from 3 to 20 % by mole of units derived from one or more alpha-olefin(s) having general formula H2C=CHR, wherein R is methyl or a linear or branched alkyl radical C3-C8; said copolymers having a molecular weight distribution with a ratio (I) of less than or equal to 4 and a (b)/(a) molar ratio of more than or equal to 2.3.
Abstract:
The present invention relates to butene-1 copolymers containing up to 40% by mol of ethylene and/or propylene derived characterized by the following properties: d) Product of the reactivity ratios rl·r2≤2; e) Content of butene-1 units in form of isotactic pentads (mmmm)>98%; and f) absence of 4,1 insertions of butene units.
Abstract:
Butene-1 (co)polymers characterized by the following properties: content of butene-1 units in the form of isotactic pentads (mmmm) from 25 to 55%; intrinsic viscosity [η] measured in tetraline at 135°C from 1 to 3dL/g; content of xylene insoluble fraction at 0°C from 3 to 60%; and a ratio ES2/ES1≥1, where ES1 is the boiling diethyl ether soluble fraction determined on the polymer as such and ES2 is the boiling diethyl ether soluble fraction determined after milling the polymer. The butene-1 (co)polymers show a good balance between processability and elastomeric behavior.
Abstract:
Propylene-ethylene copolymers are flexible and show a very good balance between softness and mechanical properties in their crude state are obtained by solution polymerization in the presence of Ziegler-Natta catalysts. The said copolymers comprise from 10 to 50%wt of ethylene and are characterized by: product of the comonomer reactivity ratio r1 r2 =1.5; absence of 2,1 propylene insertions and tensile strength at break higher than 4 Mpa.
Abstract:
Butene-1 copolymers containing: a) from 1 to 7 % by mole of ethylene derived units, and b) from 3 to 20 % by mole of units derived from one or more alpha-olefin(s) having general formula H2C=CHR, wherein R is methyl or a linear or branched alkyl radical C3-C8; said copolymers having a molecular weight distribution with a ratio (I) of less than or equal to 4 and a (b)/(a) molar ratio of more than or equal to 2.3.
Abstract:
Process for modifying the relative ratios of the components of a liquid starting mixture of specific diastereoisomers, containing at least two asymmetric carbon atoms comprising contacting said liquid mixture with a Lewis acid compound capable of co-ordinating said specific diastereoisomers and subjecting the resulting mixture to conditions such that a reaction product, having a molar ratio between its diastereoisomeric components different from the corresponding molar ratio in the said liquid starting mixture, becomes separated from the said liquid mixture, said process being carried out using an amount of said Lewis acid not enough to co-ordinate the total amount of the diastereoisomeric components of the liquid starting mixture. This method shows an excellent balance of efficiency and easiness of procedure that cannot be reached with the physical methods of diastereoisomers separation known in the art.