CA1086894A - Irradiated polymer - Google Patents
Irradiated polymerInfo
- Publication number
- CA1086894A CA1086894A CA211,030A CA211030A CA1086894A CA 1086894 A CA1086894 A CA 1086894A CA 211030 A CA211030 A CA 211030A CA 1086894 A CA1086894 A CA 1086894A
- Authority
- CA
- Canada
- Prior art keywords
- poly
- composition
- tetramethylene
- tetramethylene terephthalate
- terephthalate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J3/00—Processes of treating or compounding macromolecular substances
- C08J3/24—Crosslinking, e.g. vulcanising, of macromolecules
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C61/00—Shaping by liberation of internal stresses; Making preforms having internal stresses; Apparatus therefor
- B29C61/003—Shaping by liberation of internal stresses; Making preforms having internal stresses; Apparatus therefor characterised by the choice of material
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
- C08G63/91—Polymers modified by chemical after-treatment
- C08G63/914—Polymers modified by chemical after-treatment derived from polycarboxylic acids and polyhydroxy compounds
- C08G63/916—Dicarboxylic acids and dihydroxy compounds
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29K2067/00—Use of polyesters or derivatives thereof, as moulding material
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2367/00—Characterised by the use of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Derivatives of such polymers
- C08J2367/02—Polyesters derived from dicarboxylic acids and dihydroxy compounds
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S174/00—Electricity: conductors and insulators
- Y10S174/08—Shrinkable tubes
Landscapes
- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Treatments Of Macromolecular Shaped Articles (AREA)
- Processes Of Treating Macromolecular Substances (AREA)
- Manufacture Of Macromolecular Shaped Articles (AREA)
- Polyesters Or Polycarbonates (AREA)
Abstract
ABSTRACT
Crosslinking, for example, by irradiation, of a polymer comprising poly(tetramethylene terephthalate) is made possible by the addition of N,N'-m-phenylenedimaleimide. The resulting crosslinked modified polymer may be rendered heat-recoverable.
Crosslinking, for example, by irradiation, of a polymer comprising poly(tetramethylene terephthalate) is made possible by the addition of N,N'-m-phenylenedimaleimide. The resulting crosslinked modified polymer may be rendered heat-recoverable.
Description
~L0~6894 This invention relates to polymers, and more especially to crosslinked polymers.
The crosslinking of many polymers, by irradiation or by chemical means, to improve and modify their properties has been found useful with many polymers, for example, polyethylene, polyvinyl chloride, polyoxymethylenes and polyvinylidene di-fluoride. The presence of such polymers during crosslinking of monomers which function as crosslinking "promoters" has been known to have beneficial effects, for example, as disclosed in U.S. Patent Specifications ~os. 3,215,671 and 3,494,883. However, for some polymers only one or a few monomers ~unction effectively and even for those polymers for which a substantial number of monomers are beneficial there is a significant amount of ~ selectivity and, in many cases, a significant difference in ; 15 effectiveness of monomers. Other patent specifications disclosing such technology are United States Patent Specifications ~os.
l 2,965,553; 3,137,674 and 3,580,829. Furthermore, it is known -I that the property of heat-recoverability may be imparted to crosslinked polymars, for example, according to the pro~ess of U.S. Patent Specification ~o. 3,086,242.
However, as indicated in United States Patent Specifica-tion No. 3,142,629, not all polymers are susceptible to improve-ment by crosslinking, even with the addition of monomers which promote crosslinking in other polymers. Among polymers in wide 25 use, polyethylene terephthalate is perhaps the most significant ~~ polymer whi!ch has not been successfully crosslinked by irradia-i I tion. A closely related polymer, poly(tetramethylene terephthalat~
~ - 2 -, I ,, .
" ~,.
1 ~ .
. ~ . .. . . ~ . ~
''' '.- ~ : . , '; , ' . ' , ' '- ' ' .
l()R6894 has been found by the Applicants not to be cro~slinked when irradiated.
It has been found that the pre~ence of N,N'-m-phenylene-dimaleimide in poly (tetramethylene terephthalate) enable8 the polymer to be crosslinked, for example, when the mixture i9 irradiated.
It is within the scope of this invention if other moieties are blended or copolymerized through the agency of a monomer with poly(tetramethylene terephthalate~, provided the blending or copolymerization does not destroy the capacity of the resulting product to be crosslinked in the presence of N,N'-m-phenylenedimaleimide.
A particularly preferred blending material is the block copolymer consisting of t~o or more alternating segments of polytetramethylene ether with poly(tetramethylene tereph-thalate). Such copolymers are sold under the name Hytrel,*
for example Hytrel 4055, Hytrel 5555 and Hytrel 6355 and have the general formula: 0 0 ~CH2cH2cH2cH2o]x [CH2cH2cH2 2 ~ CO]y in which x and y may be varied over a wide range.
Preferably, the block copolymer constitutes up to 50/0 of the total composition.
The minimum effective amount of N,N'-m-phenylene dimaleimide to permit crosslinking will vary with the poly (tetramethylene terephthalate)-containing polymer under consideration. In general, from about one to about three parts-of N,N'-m-phenylenedimaleimide per hundred * denotes a trade mark.
, .. ~ . . . .
. ~ , , , " :, :
108~8~?4 parts of polymer will give beneficial results. However only routine experimentation are required to establish the effective crosslinking amount of N,N'-m-phenylene-dimaleimide, in a given case.
Radiation dose levels to achieve crosslinking according to the present invention may range from about 2 to about 80 megarads or more, but a dose of about 10 to 40 megarads is preferred. For most purposes, a dose of about 20 megarads will be effective.
The irradiation may be p~rformed while the polymer is at room temperature, but preferably the polymer is at elevated temperature, that is, above about 50C, during irradiation or is heated thereto immediately after irradiation. If the crosslinked polymer is heated, either imm-ediately or some short time after irradiation, then quenched, for example in ice water, the impact strength is improved.
The following Examples illustrate the invention.
Example 1.
One hundred parts of Tenite*6PRO, a poly(tetramethylene terephthalate) manufactured by Eastman Chemical Products, Inc., was combined with 3 parts of ~,~'-m-phenylenedimaleimide (HVA-2 manufactured by E.I. du Pont de ~emours ~ ~o. Inc., which has a melting point of about 200C and is stable at temperatures up to 2~0C.) Samples of this material were irradiated using a 1 mev electron beam to the dose levels shown in Table I. As indicated in Table I, one set of samples was irradiated at room temperature, a second set of samples was irradiated at room * denotes a trade mark.
` .
, -temperature and then immediately placed in an o~en at 145Cand a third set of samples was irradiated while ,sitting on a hot plate at 95C. After irradiation, each sample was expanded at 240C (the melting point of Tenite 6PRO is about 224 C) and held at the expanded dimension until cooled to room temp-erature. The samples were then caused to undergo heat recovery by heating to above the melting point in the absence of any physical restraint. The degree of expansion and degree of recovery are shown in Table I.
T A B L E
Elasti~ Memory M1oo (240 C) (240C) % %
15 Irradiation Conditions ~ Expansion Recovery Specimens beamed at room temperature 10 Mrads 3.8 311 99 20 Mrads 11 374 100 20 40 Mrads 59 294 100 80 Mrads 69 188 100 Specimens beamed at room temperature followed by placing immediOately in an oven at 145 C
40 Mrads 72 238100 80 Mrads 74 175100 Specimens beamed while sittingOon hot plate (ca. 95 C) under beam 10 Mrads 42 263 99 20 Mrads 59 194100 40 Mrads 75 129100 80 Mrads 89 104100 ?
As can be seen from Table I, the static modulus at 240C (M1oo) for each sample increased with increa~ing dose levels, thereby establishing that crosslinking occurred in each case. In marked contrast, a sample of Tenite 6PR0 containing no HVA-2 showed no measurable static modulus even after a do~e of 80 Mrads, thereby establishing that no measurable crosslinking occurs when the polymer alone is irradi~ted.
The results of Table I show that the crosslinked polymer is capable of being rendered heat-recoverable, with expansions 10 of over 300 % possible and recovery close to or at 100 % in each case. When non-crosslinked polymer is expanded, it is found that high expansions, for example, 100 % or more, are not use-fully obtained because the degree of recovery decreases with increasing expansion, for example, an expansion of 80 % at 145C
will recover less than 50 % of the expanded dimension~hen heated at 195C, and even at low expansions, for example, 40% or less, complete recovery is not possible, for example, an expansion of 40/0 at 145C will recover less t~an 70~0 of the expanded dimension when heated at 195C.
It may also be noted from Table I that heating either during or immediately after irradiation tbeaming) resulted in a greater degree of crosslinking at equivalent dose levels, as shown by the higher static modulus obtained when such heating occurred.
Example 2.
Test specimens in the form of injection moulded ASTM
D-638, type IV, tensile dumbbells and bars were prepared . ,~
from Tenite 6PRo and a 75 : 2S Tenit~ 6PR0/Hytrel 4055 blend.
Some specimens of each were irradiated to doses of 20 and ~o megarads. Ultimate tensile strength, ultimate elongation, and impact strength are increased by the presence of Hytrel, but tensile strength at yield and flexural elastic modulus are reduced by its presence. Broadly speaking, flexibility is increased and stiffness decreased by the presence of Hytrel.
Some representative results are shown in Table II. Each irradiated specimen contains 3 parts per hundred of HVA-2.
T A B L E II
_____________ 75 : 25 Tenite Tenite 6PR0 6PR0/Hytrel ___________ _ 4055 Ultimate tensile strength, psi7600 6000 5650 8270 7100 Tensile strength at yield, psi7300 7800 8100 5500 5900 Ultimate elongation, % 340 200 130 350 250 Impact strength~j! foot-0.68 to 0.62 to0.83 to 2.59 2.3 pounds/inch (notched) 0.81 0.73 1.04 Flexural elastic modulus, 105 ps~ 3.3 3.5 3.3 2.2 2.3 ASTM D638 was used to measure ultimate tensile strength, tensile strength at yield and ultimate elongation while ASTM
D256 was used to measure impact strength. ASTM D790 was used to measure flexural elastic modulus.
.
: ,:
10~36894 Example 3.
Samples of Tenite 6PRO containing 3 parts per hundred of HVA-2 were irradiated to doses of 10, 20, 40 and 80 megarads.
Notched impact strength determinations were then made for samples given no further treatment and for samples heated to 240C and then quickly quenched in ice water. At each dose level, it was found that the impact strength of the quenched samples was at least about twice that of the samples given no further treatment.
From the foregoing, it will be apparent that the addition of N,N'-m-phenylenedimaleimide converts poly(tetramethy-lene terephthalate) from a non-crosslinkable material to a material capable of being crosslinked. The specificity of such effects is indicated by the fact that ~,~'-m-phenylenedimalei-mide does not produce beneficial results when added to poly-oxymethylenes which embrittle seriously when irradiated inspite of the fact that triallyl cyanurate does produce beneficial results in polyoxymethylenes and both triallyl cyanurate and ~,~'-m-phenylenedimaleimide produce beneficial results in polyvinylidene fluoride.
The crosslinked poly(tetramethylene terephthalate) products of the present invention have good electrical insulation properties, good low temperature properties and ; excellent solvent resistance. Thus, such products are useful for electrical insulation, and for making heat-recoverable parts such as those disclosed in U.S. Patent Specification No. 3,243,211, issued 29th March, 1966, to J. D. Wetmore.
When poly(tetramethylene terephthalate)is blended :; ' , .
~ - 8 -` `'''' .,"
; .
10~68g4 with a block copolymer consisting of two or more alternating segments of polytetramethylene ether and poly(tetramethylene terephthalate), the amount o~ copolymer added may vary over wide limits depending on the properties desired. The blend may contain up to 50 % or more of the copolymer.
Example 4 .
A poly(tetramethylene terephthalate) Tenite 6PR0 containing N,N'm-phenylenedimaleimide was fabricated into sheet form. Following irradiation crosslinking, this sheet was vacuum formed easily into various shapes. Sheet of Tenite 6 PR0 not containing ~,~'-m-phenylenedimaleimide and not cross-linkable is very difficult to vacuum form because at the forming temperature the plastic lacks sufficient melt strength to prevent excessive sagging or melting. Crosslinking increases melt stength ~viscosity)permitting heating of sheet for vacuum forming without excessive sagging or melting.
It will be appreciated that the specified monomer is useful to assist the crosslinking effectiveness of chemical cross-linking agents, for example, peroxides, in poly(tetramethylene terephthalate) as well as being useful in both radiation and ; chemical crosslinking of copoly~ers of tetramethylene tere-phthalate, for example, those block copolymers discussed above as suitable for ~lending with the h~mopolymer, -_ g _ ;
:, . :
' :' ' ; ' ' ~
The crosslinking of many polymers, by irradiation or by chemical means, to improve and modify their properties has been found useful with many polymers, for example, polyethylene, polyvinyl chloride, polyoxymethylenes and polyvinylidene di-fluoride. The presence of such polymers during crosslinking of monomers which function as crosslinking "promoters" has been known to have beneficial effects, for example, as disclosed in U.S. Patent Specifications ~os. 3,215,671 and 3,494,883. However, for some polymers only one or a few monomers ~unction effectively and even for those polymers for which a substantial number of monomers are beneficial there is a significant amount of ~ selectivity and, in many cases, a significant difference in ; 15 effectiveness of monomers. Other patent specifications disclosing such technology are United States Patent Specifications ~os.
l 2,965,553; 3,137,674 and 3,580,829. Furthermore, it is known -I that the property of heat-recoverability may be imparted to crosslinked polymars, for example, according to the pro~ess of U.S. Patent Specification ~o. 3,086,242.
However, as indicated in United States Patent Specifica-tion No. 3,142,629, not all polymers are susceptible to improve-ment by crosslinking, even with the addition of monomers which promote crosslinking in other polymers. Among polymers in wide 25 use, polyethylene terephthalate is perhaps the most significant ~~ polymer whi!ch has not been successfully crosslinked by irradia-i I tion. A closely related polymer, poly(tetramethylene terephthalat~
~ - 2 -, I ,, .
" ~,.
1 ~ .
. ~ . .. . . ~ . ~
''' '.- ~ : . , '; , ' . ' , ' '- ' ' .
l()R6894 has been found by the Applicants not to be cro~slinked when irradiated.
It has been found that the pre~ence of N,N'-m-phenylene-dimaleimide in poly (tetramethylene terephthalate) enable8 the polymer to be crosslinked, for example, when the mixture i9 irradiated.
It is within the scope of this invention if other moieties are blended or copolymerized through the agency of a monomer with poly(tetramethylene terephthalate~, provided the blending or copolymerization does not destroy the capacity of the resulting product to be crosslinked in the presence of N,N'-m-phenylenedimaleimide.
A particularly preferred blending material is the block copolymer consisting of t~o or more alternating segments of polytetramethylene ether with poly(tetramethylene tereph-thalate). Such copolymers are sold under the name Hytrel,*
for example Hytrel 4055, Hytrel 5555 and Hytrel 6355 and have the general formula: 0 0 ~CH2cH2cH2cH2o]x [CH2cH2cH2 2 ~ CO]y in which x and y may be varied over a wide range.
Preferably, the block copolymer constitutes up to 50/0 of the total composition.
The minimum effective amount of N,N'-m-phenylene dimaleimide to permit crosslinking will vary with the poly (tetramethylene terephthalate)-containing polymer under consideration. In general, from about one to about three parts-of N,N'-m-phenylenedimaleimide per hundred * denotes a trade mark.
, .. ~ . . . .
. ~ , , , " :, :
108~8~?4 parts of polymer will give beneficial results. However only routine experimentation are required to establish the effective crosslinking amount of N,N'-m-phenylene-dimaleimide, in a given case.
Radiation dose levels to achieve crosslinking according to the present invention may range from about 2 to about 80 megarads or more, but a dose of about 10 to 40 megarads is preferred. For most purposes, a dose of about 20 megarads will be effective.
The irradiation may be p~rformed while the polymer is at room temperature, but preferably the polymer is at elevated temperature, that is, above about 50C, during irradiation or is heated thereto immediately after irradiation. If the crosslinked polymer is heated, either imm-ediately or some short time after irradiation, then quenched, for example in ice water, the impact strength is improved.
The following Examples illustrate the invention.
Example 1.
One hundred parts of Tenite*6PRO, a poly(tetramethylene terephthalate) manufactured by Eastman Chemical Products, Inc., was combined with 3 parts of ~,~'-m-phenylenedimaleimide (HVA-2 manufactured by E.I. du Pont de ~emours ~ ~o. Inc., which has a melting point of about 200C and is stable at temperatures up to 2~0C.) Samples of this material were irradiated using a 1 mev electron beam to the dose levels shown in Table I. As indicated in Table I, one set of samples was irradiated at room temperature, a second set of samples was irradiated at room * denotes a trade mark.
` .
, -temperature and then immediately placed in an o~en at 145Cand a third set of samples was irradiated while ,sitting on a hot plate at 95C. After irradiation, each sample was expanded at 240C (the melting point of Tenite 6PRO is about 224 C) and held at the expanded dimension until cooled to room temp-erature. The samples were then caused to undergo heat recovery by heating to above the melting point in the absence of any physical restraint. The degree of expansion and degree of recovery are shown in Table I.
T A B L E
Elasti~ Memory M1oo (240 C) (240C) % %
15 Irradiation Conditions ~ Expansion Recovery Specimens beamed at room temperature 10 Mrads 3.8 311 99 20 Mrads 11 374 100 20 40 Mrads 59 294 100 80 Mrads 69 188 100 Specimens beamed at room temperature followed by placing immediOately in an oven at 145 C
40 Mrads 72 238100 80 Mrads 74 175100 Specimens beamed while sittingOon hot plate (ca. 95 C) under beam 10 Mrads 42 263 99 20 Mrads 59 194100 40 Mrads 75 129100 80 Mrads 89 104100 ?
As can be seen from Table I, the static modulus at 240C (M1oo) for each sample increased with increa~ing dose levels, thereby establishing that crosslinking occurred in each case. In marked contrast, a sample of Tenite 6PR0 containing no HVA-2 showed no measurable static modulus even after a do~e of 80 Mrads, thereby establishing that no measurable crosslinking occurs when the polymer alone is irradi~ted.
The results of Table I show that the crosslinked polymer is capable of being rendered heat-recoverable, with expansions 10 of over 300 % possible and recovery close to or at 100 % in each case. When non-crosslinked polymer is expanded, it is found that high expansions, for example, 100 % or more, are not use-fully obtained because the degree of recovery decreases with increasing expansion, for example, an expansion of 80 % at 145C
will recover less than 50 % of the expanded dimension~hen heated at 195C, and even at low expansions, for example, 40% or less, complete recovery is not possible, for example, an expansion of 40/0 at 145C will recover less t~an 70~0 of the expanded dimension when heated at 195C.
It may also be noted from Table I that heating either during or immediately after irradiation tbeaming) resulted in a greater degree of crosslinking at equivalent dose levels, as shown by the higher static modulus obtained when such heating occurred.
Example 2.
Test specimens in the form of injection moulded ASTM
D-638, type IV, tensile dumbbells and bars were prepared . ,~
from Tenite 6PRo and a 75 : 2S Tenit~ 6PR0/Hytrel 4055 blend.
Some specimens of each were irradiated to doses of 20 and ~o megarads. Ultimate tensile strength, ultimate elongation, and impact strength are increased by the presence of Hytrel, but tensile strength at yield and flexural elastic modulus are reduced by its presence. Broadly speaking, flexibility is increased and stiffness decreased by the presence of Hytrel.
Some representative results are shown in Table II. Each irradiated specimen contains 3 parts per hundred of HVA-2.
T A B L E II
_____________ 75 : 25 Tenite Tenite 6PR0 6PR0/Hytrel ___________ _ 4055 Ultimate tensile strength, psi7600 6000 5650 8270 7100 Tensile strength at yield, psi7300 7800 8100 5500 5900 Ultimate elongation, % 340 200 130 350 250 Impact strength~j! foot-0.68 to 0.62 to0.83 to 2.59 2.3 pounds/inch (notched) 0.81 0.73 1.04 Flexural elastic modulus, 105 ps~ 3.3 3.5 3.3 2.2 2.3 ASTM D638 was used to measure ultimate tensile strength, tensile strength at yield and ultimate elongation while ASTM
D256 was used to measure impact strength. ASTM D790 was used to measure flexural elastic modulus.
.
: ,:
10~36894 Example 3.
Samples of Tenite 6PRO containing 3 parts per hundred of HVA-2 were irradiated to doses of 10, 20, 40 and 80 megarads.
Notched impact strength determinations were then made for samples given no further treatment and for samples heated to 240C and then quickly quenched in ice water. At each dose level, it was found that the impact strength of the quenched samples was at least about twice that of the samples given no further treatment.
From the foregoing, it will be apparent that the addition of N,N'-m-phenylenedimaleimide converts poly(tetramethy-lene terephthalate) from a non-crosslinkable material to a material capable of being crosslinked. The specificity of such effects is indicated by the fact that ~,~'-m-phenylenedimalei-mide does not produce beneficial results when added to poly-oxymethylenes which embrittle seriously when irradiated inspite of the fact that triallyl cyanurate does produce beneficial results in polyoxymethylenes and both triallyl cyanurate and ~,~'-m-phenylenedimaleimide produce beneficial results in polyvinylidene fluoride.
The crosslinked poly(tetramethylene terephthalate) products of the present invention have good electrical insulation properties, good low temperature properties and ; excellent solvent resistance. Thus, such products are useful for electrical insulation, and for making heat-recoverable parts such as those disclosed in U.S. Patent Specification No. 3,243,211, issued 29th March, 1966, to J. D. Wetmore.
When poly(tetramethylene terephthalate)is blended :; ' , .
~ - 8 -` `'''' .,"
; .
10~68g4 with a block copolymer consisting of two or more alternating segments of polytetramethylene ether and poly(tetramethylene terephthalate), the amount o~ copolymer added may vary over wide limits depending on the properties desired. The blend may contain up to 50 % or more of the copolymer.
Example 4 .
A poly(tetramethylene terephthalate) Tenite 6PR0 containing N,N'm-phenylenedimaleimide was fabricated into sheet form. Following irradiation crosslinking, this sheet was vacuum formed easily into various shapes. Sheet of Tenite 6 PR0 not containing ~,~'-m-phenylenedimaleimide and not cross-linkable is very difficult to vacuum form because at the forming temperature the plastic lacks sufficient melt strength to prevent excessive sagging or melting. Crosslinking increases melt stength ~viscosity)permitting heating of sheet for vacuum forming without excessive sagging or melting.
It will be appreciated that the specified monomer is useful to assist the crosslinking effectiveness of chemical cross-linking agents, for example, peroxides, in poly(tetramethylene terephthalate) as well as being useful in both radiation and ; chemical crosslinking of copoly~ers of tetramethylene tere-phthalate, for example, those block copolymers discussed above as suitable for ~lending with the h~mopolymer, -_ g _ ;
:, . :
' :' ' ; ' ' ~
Claims (15)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A process for the manufacture of crosslinked poly(tetramethylene terephthalate) which comprises irradiating poly(tetramethylene terephthalate) containing N,N'-m-phenylene dimaleimide.
2. A process as claimed in claim 1, wherein the N,N'-m-phenylene dimaleimide is present at a ratio of at least 1 part by weight per 100 parts of poly(tetra-methylene terephthalate).
3. A process as claimed in claim 1 or claim 2, wherein the polymer is heated during or immediately after irradiation.
4. A process as claimed in claim 1 or claim 2, wherein the radiation dose is from 2 to 80 Mrad.
5. A process as claimed in claim 1 or claim 2, wherein the radiation dose is from 10 to 40 Mrad.
6. A process as claimed in claim 1 or claim 2, wherein the crosslinked polymer is subsequently heated to above its melting point and quenched, whereby its impact strength is improved.
7. A process as claimed in claim 1, wherein the poly(tetramethylene terephthalate) is blended with a block copolymer of tetramethylene ether and tetramethylene terephthalate before being crosslinked.
8. A process as claimed in claim 7, wherein the block copolymer constitutes up to 50% by weight of the blend.
9. A crosslinked polymer based on poly(tetramethylene terephthalate) and comprising units derived from N,N'-m-phenylene dimaleimide.
10. A composition comprising poly(tetramethylene terephthalate) in admixture with N,N'-m-phenylenedimaleimide.
11. A composition comprising poly(tetramethylene terephthalate) and at least 1 part per hundred by weight thereof of N,N'-m-phenylenedimaleimide.
12. A composition as claimed in claim 10, which also comprises a block copolymer of tetramethylene ether and tetramethylene terephthalate.
13. A composition as claimed in claim 12, wherein the block copolymer constitutes up to 50% by weight of the composition.
14. A shaped structure comprising a composition as claimed in claim 9.
15. A heat recoverable shaped structure comprising a composition as claimed in claim 9.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US405522 | 1973-10-11 | ||
| US05/405,522 US3968015A (en) | 1973-10-11 | 1973-10-11 | Poly(tetramethyleneterephthalate) crosslinked by irradiation |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1086894A true CA1086894A (en) | 1980-09-30 |
Family
ID=23604046
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA211,030A Expired CA1086894A (en) | 1973-10-11 | 1974-10-08 | Irradiated polymer |
Country Status (5)
| Country | Link |
|---|---|
| US (2) | US3968015A (en) |
| CA (1) | CA1086894A (en) |
| DE (1) | DE2448414A1 (en) |
| FR (1) | FR2247493B1 (en) |
| GB (1) | GB1486207A (en) |
Families Citing this family (21)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4113594A (en) * | 1973-10-11 | 1978-09-12 | Raychem Corporation | Poly(tetramethyleneterephthalate) crosslinked by irradiation |
| US3968015A (en) * | 1973-10-11 | 1976-07-06 | Raychem Corporation | Poly(tetramethyleneterephthalate) crosslinked by irradiation |
| US4256558A (en) * | 1976-10-12 | 1981-03-17 | Teijin Limited | Cured or uncured linear aromatic polyester composition and process for preparation thereof |
| US4121001A (en) * | 1977-01-14 | 1978-10-17 | Raychem Corporation | Crosslinking agent for polymers and wire construction utilizing crosslinked polymers |
| USRE31103E (en) * | 1977-01-14 | 1982-12-14 | Raychem Corporation | Crosslinking agent for polymers and wire construction utilizing crosslinked polymers |
| GB1603205A (en) * | 1977-04-12 | 1981-11-18 | Raychem Ltd | Polymer compositions |
| US4269947A (en) * | 1977-07-05 | 1981-05-26 | Teijin Limited | Cured or uncured aromatic polyester composition and process for its production |
| US4110187A (en) * | 1977-09-02 | 1978-08-29 | Eastman Kodak Company | Ultraviolet curable polyester binder and coating formulation |
| US4292151A (en) * | 1978-03-01 | 1981-09-29 | Teijin Limited | Process for preparing a cured copolyetherester elastomeric composition |
| US4323607A (en) * | 1978-09-01 | 1982-04-06 | Ube Industries, Ltd. | Heat shrinkable covers |
| US4200731A (en) * | 1979-02-01 | 1980-04-29 | The Goodyear Tire & Rubber Company | Endcapped polyesters |
| DE2915011A1 (en) * | 1979-04-12 | 1980-10-30 | Herberts Gmbh | MODIFIED POLYESTERIMIDES CURRENT BY ENERGY RADIATION, METHOD FOR THE PRODUCTION THEREOF AND THEIR USE FOR THE INSULATION OF ELECTRIC WIRE |
| AU6141980A (en) * | 1979-08-28 | 1981-03-05 | Bicc Ltd. | Heat recoverable articles |
| US4444816A (en) * | 1980-12-03 | 1984-04-24 | Raychem Corporation | Radiation cross-linking of polyamides |
| US4518819A (en) * | 1981-07-30 | 1985-05-21 | Raychem Corporation | Clamp assembly for power cables |
| US4650228A (en) * | 1983-09-14 | 1987-03-17 | Raychem Corporation | Heat-recoverable coupling assembly |
| US4939819A (en) * | 1989-06-28 | 1990-07-10 | The Bentley-Harris Manufacturing Company | Wraparound closure device |
| US5916937A (en) * | 1997-09-30 | 1999-06-29 | General Electric Company | Heat cured fluorosilicone rubber compositions having improved compression set |
| TW591341B (en) * | 2001-09-26 | 2004-06-11 | Shipley Co Llc | Coating compositions for use with an overcoated photoresist |
| US20060009539A1 (en) * | 2004-07-12 | 2006-01-12 | Herr Donald E | Maleimide-based radiation curable compositions |
| KR100867661B1 (en) * | 2006-12-27 | 2008-11-10 | 전자부품연구원 | Thermally Curable Resin Composition Having Low Dielectric Constant and Low Dielectric Loss in High Frequency Range |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2071250A (en) * | 1931-07-03 | 1937-02-16 | Du Pont | Linear condensation polymers |
| US2965553A (en) * | 1956-05-25 | 1960-12-20 | Du Pont | Curing of high molecular weight polymers |
| US2951024A (en) * | 1957-03-22 | 1960-08-30 | Bardal Inc | Irradiated polymers |
| US3728212A (en) * | 1967-10-02 | 1973-04-17 | Eastman Kodak Co | Hot melt adhesive of poly(tetramethylene)terephthalate and polystyrene or polystyrene copolymers |
| US3717615A (en) * | 1969-04-25 | 1973-02-20 | Gen Electric | Polyimides |
| DE2031573A1 (en) * | 1969-07-01 | 1971-01-07 | General Electric Co., Schenectady, N Y (V.St.A.) | Imido-substituted polyesters and processes for their preparation |
| US3770697A (en) * | 1969-07-01 | 1973-11-06 | Gen Electric | Curable polycarbonate compositions |
| BE793332A (en) * | 1972-01-26 | 1973-04-16 | Du Pont | THERMOPLASTIC COPOLYESTERS WITH SEGMENTS |
| BE794029A (en) * | 1972-02-28 | 1973-05-02 | Du Pont | THERMOPLASTIC COPOLYESTERS WITH SEGMENTS MODIFIED BY POLYEPOXIDES |
| US3968015A (en) * | 1973-10-11 | 1976-07-06 | Raychem Corporation | Poly(tetramethyleneterephthalate) crosslinked by irradiation |
-
1973
- 1973-10-11 US US05/405,522 patent/US3968015A/en not_active Expired - Lifetime
-
1974
- 1974-10-08 CA CA211,030A patent/CA1086894A/en not_active Expired
- 1974-10-10 DE DE19742448414 patent/DE2448414A1/en active Pending
- 1974-10-11 GB GB44271/74A patent/GB1486207A/en not_active Expired
- 1974-10-11 FR FR7434257A patent/FR2247493B1/fr not_active Expired
-
1976
- 1976-07-02 US US05/702,202 patent/US4073830A/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| GB1486207A (en) | 1977-09-21 |
| FR2247493B1 (en) | 1980-03-28 |
| US4073830A (en) | 1978-02-14 |
| DE2448414A1 (en) | 1975-04-24 |
| FR2247493A1 (en) | 1975-05-09 |
| US3968015A (en) | 1976-07-06 |
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