ALIPHATIC AND SEMI-AROMATIC POLYAMIDES WITH DIMER ACIDS AND DIMER AMINES
A polyamide composition comprising from 45 wt % to 95 wt % of polyamide polymer and from 5 wt % to 55 wt % of a modifier comprising a C 18-44 dimer acid or a C 18-44 dimer amine or a combination thereof. A number average molecular weight of the polyamide polymer is less than 30,000 g/mol. The polyamide composition has a chemical resistance, as measured by exposure to HCl (10%) for 14 days at 58° C., resulting in a weight loss of less than 3.0 wt %; and a moisture uptake of less than about 2.0 wt % moisture at 95% RH. A process for preparing the polyamide composition is also disclosed.
1 . A polyamide composition comprising:
from 45 wt % to 95 wt % of polyamide polymer;
from 5 wt % to 55 wt % of a modifier comprising a C 18-44 dimer acid or a C 18-44 dimer amine or a combination thereof;
wherein the polyamide composition has:
a number average molecular weight of the polyamide polymer is less than 30,000 g/mol;
a chemical resistance, as measured by exposure to HCl (10%) for 14 days at 58° C., resulting in a weight loss of less than 3.0 wt %; and
a moisture uptake of less than about 2.0 wt % moisture at 95% RH.
2 . The polyamide composition of claim 1 , wherein the polyamide polymer comprises PA10, PA11, PA12, PA6,6, PA6,9, PA6,10, PA6,11, PA6,12, PA6,13, PA6,14, PA6,15, PA6,16, PA6,17, PA6,18, PA10,10, PA10,12, PA12,12, PA9T, PA10T, PA11T, PA12T, PA6T/66, PA6T/6I, PA6T/6I/66, PA6T/DT, PA6,T/6,10, PA6,T/6,12, PA6,T/6,13, PA6,T/6,14, PA6,T/6,15, PA6,T/6,16, PA6,T/6,17, PA6,T/6,18, PA6,C/6,10, PA6,C/6,12, PA6,C/6,13, PA6,C/6,14, PA6,C/6,15, PA6,C/6,16, PA6,C/6,17, or PA6,C/6,18, or combinations thereof.
3 . The polyamide composition of claim 2 , wherein the polyamide polymer comprises PA6,10, PA6,12, or combinations thereof.
4 . The polyamide composition of claim 1 , wherein composition comprises a single modifier comprising either a single dimer acid or a single dimer amine.
5 . The polyamide composition of claim 1 , wherein the polyamide composition has a melting temperature from 165° C. to 270° C.
6 . The polyamide composition of claim 5 , wherein the polyamide composition has a melting temperature from 170° C. to 215° C.
7 . The polyamide composition of claim 1 , wherein the polyamide composition comprises from 20 wt % to 45 wt % of the modifier.
8 . The polyamide composition of claim 1 , wherein the polyamide composition has a methyl/amide ratio ranging from 6:1 to 15:1.
9 . The polyamide composition of claim 1 , wherein the number average molecular weight of the polyamide polymer ranges from 10,000 g/mol to 25,000 g/mol.
10 . The polyamide composition of claim 1 , wherein the polyamide polymer has an amine end group content ranging from 10 microeq/g to 110 microeq/g.
11 . The polyamide composition of claim 1 , further comprising glass fibers present in an amount greater than 5 wt %.
12 . The polyamide composition of claim 1 , further comprising a lubricant present in an amount greater than 0.3 wt %.
13 . The polyamide composition of claim 1 , further comprising an impact modifier present in an amount greater than 3 wt %.
14 . The polyamide composition of claim 1 , wherein the polyamide polymer comprises PA6,12, and the dimer modifier is present in an amount ranging from 15 wt % to 50 wt %, wherein one of either:
the dimer modifier is a single dimer amine and the polyamide composition demonstrates a tensile elongation of at least 50%; and,
the dimer modifier is a single dimer acid and the polyamide composition demonstrates a tensile elongation of at least 20%.
15 . The polyamide composition of claim 1 , wherein the polyamide polymer comprises PA6,12, the dimer modifier is a single dimer amine present in an amount ranging from 35 wt % to 55 wt %, and wherein the polyamide composition demonstrates a notched Charpy impact energy loss at 23° C. that is greater than 4.5 kJ/m 2 .
16 . The polyamide composition of claim 1 , wherein the polyamide polymer comprises PA6,12, the dimer modifier is in an amount of about 20 wt %, and wherein the polyamide composition demonstrates a notched Charpy impact energy loss at 23° C. that is greater than 3.5 kJ/m 2 , a tensile strength greater than 50 MPa, and a tensile modulus greater than 1950 MPa.
17 . A molded article comprising:
a polyamide composition comprising:
from 45 wt % to 95 wt % of polyamide polymer;
from 5 wt % to 55 wt % of a modifier comprising a C 18-44 dimer acid or a C 18-44 dimer amine or a combination thereof;
wherein the molded article composition has:
a number average molecular weight of the polyamide polymer is less than 30,000 g/mol;
a chemical resistance, as measured by exposure to HCl (10%) for 14 days at 58° C., resulting in a weight loss of less than 3.0 wt %; and
a moisture uptake of less than about 2.0 wt % moisture at 95% RH.
18 . A process for preparing a polyamide composition comprising:
preparing a high solids monomer solution in aqueous salts, wherein the solids content is greater than 80%;
evaporating the high solids monomer solution in an evaporator, wherein starting concentrations are greater than 60 wt %; and,
adding a modifier comprising a C 18-44 dimer acid or a C 18-44 dimer amine or a combination thereof to form a single mixture, wherein the modifier bypasses the evaporator;
wherein the polyamide composition demonstrates:
a number average molecular weight of the polyamide polymer is less than 30,000 g/mol;
a chemical resistance, as measured by exposure to HCl (10%) for 14 days at 58° C., resulting in a weight loss of less than 3.0 wt %; and
a moisture uptake of less than about 2.0 wt % moisture at 95% RH.
19 . The process of claim 18 , wherein the polyamide polymer comprises PA6,10, PA6,12, or combinations thereof.
20 . The process of claim 18 , wherein the modifier is a single modifier comprising either a single C 18-44 dimer acid or a single C 18-44 dimer amine.