EP0593664A4 - Blend of flexible coil polymer and thermotropic liquid crystal segmented block copolymer - Google Patents
Blend of flexible coil polymer and thermotropic liquid crystal segmented block copolymerInfo
- Publication number
- EP0593664A4 EP0593664A4 EP19920915938 EP92915938A EP0593664A4 EP 0593664 A4 EP0593664 A4 EP 0593664A4 EP 19920915938 EP19920915938 EP 19920915938 EP 92915938 A EP92915938 A EP 92915938A EP 0593664 A4 EP0593664 A4 EP 0593664A4
- Authority
- EP
- European Patent Office
- Prior art keywords
- pbt
- lcp
- blend
- flexible coil
- blends
- 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.)
- Withdrawn
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L67/00—Compositions of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Compositions of derivatives of such polymers
- C08L67/02—Polyesters derived from dicarboxylic acids and dihydroxy compounds
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L67/00—Compositions of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Compositions of derivatives of such polymers
- C08L67/02—Polyesters derived from dicarboxylic acids and dihydroxy compounds
- C08L67/025—Polyesters derived from dicarboxylic acids and dihydroxy compounds containing polyether sequences
Definitions
- LCPs main chain thermotropic liquid crystal polymers
- LC phase When processed in the mesophase state, LCPs generally provide many advantages over random coil polymers because most LCPs have an intrinsically low melt viscosity in the nematic melt and a tendency toward easy orientation in the flow direction. Furthermore, it is well known that oriented LCPs relax very slowly and therefore the orientation developed in a processed melt may be retained after solidification. Under controlled processing conditions droplets of the LC phase can be induced to form elongated or even fibrillar domains in which the molecular chains are highly aligned yielding self-reinforcement.
- Blends of a thermotropic liquid crystalline polymer (TLCP) with a flexible coil-like polymer may achieve the characteristics of TLCP, but at a lower cost.
- the TLCP which is initially dispersed as spheres or droplets in the matrix can be elongated in adequate flow-fields to give reinforcement.
- Recent work in the literature has described blends of a TLCP with coil-like polymers including poly(ethylene terephthalate) , poly(butylene terephthalate) , polycarbonate, polyamide and polyethers as matrix materials.
- Exemplary art considered to be generally relevant to the instant invention, to be described hereinafter, are: Shin et al., Polymer. Eng. and Sci., Vol. 30, No.
- TLCP orientation of the TLCP and the degree of interfacial adherence between fiber and matrix are both important factors for the strength of such a blend composite material.
- a major difficulty in such TLCP blend systems derives from the techniques of dispersing the rigid-rod molecules in the matrix of flexible coil molecules. If the interfacial interaction force between the TLCP and matrix is strong enough, the dispersion can proceed until the interfacial energy is balanced with the aggregation energy of rigid molecules.
- block/matrix blends such as poly(p-phenylene terephthala ide)/nylon and poly(p- benzamide) /nylon block copolymers blended into a nylon matrix showed improved properties over the normal blends with equivalent rod-like polymer loading.
- block copolymers of rigid and flexible polymers are considered by the present inventors to have great potential in self-reinforced composites.
- dilute solutions must be employed in order to obtain good dispersion because the rod-like molecules aggregate above a certain critical concentration.
- a TLCP in-situ composite would be expected to have the same merits as lyotropic LCP systems, but would have the advantages of melt processability and well dispersed mixing.
- the present invention in its broadest embodiment, relates to a blend which comprises a flexible coil polymer matrix and a thermotropic liquid crystal block, as contrasted to random, copolymer comprising segmented mesogenic and segmented flexible coil blocks.
- the flexible coil blocks are substantially similar to the flexible coil polymer of the matrix.
- the present invention in a more narrow, but preferred, embodiment relates to a blend of a polyester, such as polybutylene terephthalate (PBT) , and a novel block copolymer of a liquid crystal polymer containing a triad aromatic ester mesogen unit with flexible polyalkylene spacer and a polyester, such as PBT, as the flexible coil.
- the polyester matrix is substantially similar in structure to the polyester resin forming one component of the liquid crystal polymer/polyester block copolymer.
- the polyalkylene moieties in the polyester in the matrix and segmented block copolymer are identical, for example, butylene.
- liquid crystalline segmented block copolymer which is intended to be added to the selected flexible coil polymer matrix can be envisioned to have the general formula:
- Rod indicates the mesogenic block with x, normally from 2 to 50, indicating the number of mesogen repeats
- "Coil” indicating the block comprising the flexible coil polymer
- y normally from about 2 to about 50, indicating the number of repeat units of the flexible coil polymer
- p representing the repeat units of Rod and Coil blocks.
- the mole % rod in the total polymer can range from about 4% to about 80%.
- the repeat unit p can range from about 1 to about very large numbers such as 50-500 for high molecular weight segmented block copolymers.
- the rod length which is responsible for liquid crystalline properties for the block copolymer additive (which is the subject of U.S. Serial No. , filed on even date herewith) and the % block in the matrix/block copolymer combination need to be appropriately balanced within the general ranges given above so that there is liquid crystalline properties imparted to the additive so that appropriate phase separation, with creation of domains of rod and coil, is created with a concomitant reinforcement of the entire blend.
- the flexible coil polymer matrix for the instant blend invention can be selected from known polyester and polyamide polymers such as poly(ethylene terephthalate) , poly(butylene terephthalate) nylon-6,6, nylon 6, amorphous nylons, and polyester thermoplastic elastomers based on PBT and polytetra ethylene oxide units.
- polyester and polyamide polymers such as poly(ethylene terephthalate) , poly(butylene terephthalate) nylon-6,6, nylon 6, amorphous nylons, and polyester thermoplastic elastomers based on PBT and polytetra ethylene oxide units.
- the type of mesogenic unit for the rod portion of the LC copolymer can be appropriately selected from known mesogenic units (main chain thermotropic liquid crystal polymers) including those of the general structure:
- Another mesogenic unit which can be employed has the structure -Ar-C(0)-NH-Ar-NH-C(0)-Ar-.
- the commercial rod polymers based on oxybenzoate units, 4,4'-biphenylene terephthalate units, and oxynaphthalene carboxylate units can be especially preferred.
- the flexible coil block in the block copolymer segment described above should be substantially similar to the matrix material by being either substantially the same in regard to the repeat units of the matrix or by having some of the same repeat units. Thus, if a PET matrix is chosen a PET block segment in the copolymer would be selected.
- thermotropic LCP block triad with flexible spacer block and polyester block
- structure (I) is not a true rigid-rod, it readily assumes an extended chain structure and forms nematic mesophases and consequently high modulus/strength structures.
- the high strength chain extended block polymer molecules would be very finely dispersed in a PBT matrix and would be expected to have potential as a high performance molecular composite material.
- the LCP segmented block copolymer (triad mesogenic unit with flexible spacer and polyester segment) can be advantageously prepared in a two step-reaction sequence.
- low oligomers of the triad oligomer can be prepared by the following reaction: O 0
- Ar is paraphenylene
- a can be 2-50
- b can be 2-50
- n is the length of the spacer, e.g., 2-10, 2 or 4 most preferably
- T' is (para)-OCArCO-.
- low oligomers of the polyester e.g., preferably either ethylene terephthalate or butylene terephthalate
- the polyester e.g., preferably either ethylene terephthalate or butylene terephthalate
- the end-groups of the triad oligomer and the polyester oligomers can be selected as either acyl chloride or hydroxyl, respectively (or the converse) , depending on the chosen preselected stoichiometry. For example, preparation of the triad oligomer with hydroxyl end-groups necessitates the preparation of the polyester oligomer with acyl chloride end-groups, and vice versa.
- the oligomers can be allowed to react with each other to produce the desired block copolymer according to the following sequence:
- the same block copolymer may be prepared from acyl chloride end-groups on the triad oligomer and hydroxyl end-groups on the polyester oligomer in the two step sequence shown below: Step 1:
- Polyester Oligomer Step 2 p Polyester Oligomer + p Triad Oligomer >
- both the length of the blocks and the composition of the copolymer may be controlled.
- the sizes of the oligomers can be controlled by the stoichiometric ratios of the triad monomer to terephthaloyl chloride and bis(hydroxyalkyl)terephthalate to terephthaloyl chloride.
- Polarized optical microscopy (POM) results have shown that these block copolymers form nematic liquid crystal phases above T m , as shown by Schlieren textures.
- the following Example and related Experimentals section sets forth one preferred material of this type and a process to make it.
- This Example illustrates preparation of a triad-4 poly(butylene terephthalate) (PBT) copolymer (B) with an average block size of five triad-4 terephthalate and eight » 5 butylene terephthalate units in the corresponding blocks.
- PBT poly(butylene terephthalate)
- B poly(butylene terephthalate) copolymer
- Triad-4" is meant to be a shorthand designation for the triad aromatic ester mesogenic unit shown in Ober et al. , Polymer J. , Vol. 14, No. 1 (1982) on page 9 where the formula (Series
- BHBT Bis-(hydroxybutyl) terephthalate
- terephthaloyl chloride 3.271 gm, 1.6111 x 10" 2 mol
- Triad-4 monomer 5.322 gm, 1.6111 x 10 "2 mol
- terephthaloyl chloride 2.617 gm, 1.2889 x 10 "2 mol
- the LCP copolymer used was a block polymer made in Example 1, above (hereinafter termed "LCP-b-PBT (5/8)"), which consisted of blocks of a triad aromatic ester mesogenic unit containing an alkylene spacer (C 4 alkylene) of the type described by Lenz et al. in Polym. J. , Vol. 14, p. 9 (1982).
- LCP-b-PBT a block polymer made in Example 1, above
- C 4 alkylene alkylene spacer
- the PBT block may increase the compatibility and dispersity of the LCP/PBT blend.
- the thermal properties and inherent viscosities of LCP-b- PBT and pure PBT are listed in Table 1:
- the vacuum dried blend and pure component polymer precipitates were combined in a hot-press at 210°C and 2500 15 kg/cm 2 for a brief period of time. These irregular films were immediately removed from the press and were quenched in cold water.
- the residence time in the capillary extruder was 2 to 3 minutes.
- the extrudate was elongated by a take-up machine below the die.
- the draw ratio (DR) was determined by measuring the 25 reduction in fiber diameter by either laser diffraction or optical microscopy. It is understood that the term “draw ratio” as used herein is to be construed as relating to "drawn as spun”, also termed “jet draw” or "jet stretch”.
- Tensile properties were measured at 10 or 20 m /min 30 cross-head speed on an Instron Mechanical Tester at ambient conditions in the laboratory. Each tensile property was averaged over six tests.
- Morphology was characterized using a JEOL [JSM-35C] scanning electron microscope with an accelerating voltage of 35 25 kv.
- Fracture surfaces were prepared by snapping the materials after cooling in liquid nitrogen. To observe the deformation of dispersed LCP-b-PBT particles in the blend, the strands stretched by the tensile tester were also examined. These samples were mounted on aluminum stubs and sputtered with gold using an SPI Sputter Coater for enhanced conductivity. A Perkin-Elmer model DSC-7 was used for thermal characterization. A heating rate of 20°C/min was utilized, and the samples were scanned from 40°C to 300°C.
- thermograms of the LCP-b-PBT and the pure PBT were taken.
- the parameters determined from the thermograms are given in Table 1, above.
- the crystal to nematic transition for the LCP-b-PBT and isotropic melt for the PBT were 210°C and 225°C, respectively.
- the cooling cycle thermogram showed a considerable super- cooling of the mesophase to solid crystal transition.
- the nematic nature of the LCP-b-PBT polymer was identified by a thread-like Schlieren texture observed by cross-polarized optical microscopy, as mentioned earlier.
- the biphasic region, mesophase and isotropic state was observed at around 265°C, before partial isotropization commenced.
- the heat of isotropization of LCP-b-PBT in the blend was observed to decrease with increasing PBT content and eventually disappeared. Furthermore, there was a depression in the melting point of PBT with increasing blend composition. Both the melting and isotropic transition of LCP-b-PBT in the blends with higher PBT content (90%) could not be detected.
- the blends with 50/50, LCP-b-PBT/PBT were annealed at 260°C which was just above the processing temperature employed in this work, and at 300°C which is in the completely isotropic range.
- T m melting transition
- the pure LCP-b-PBT fiber fracture surfaces were also imaged by SEM.
- the fiber was extruded through a die of a capillary rheometer.
- extruded strand of pure LCP-b-PBT with draw ratios over 1 could not be obtained because of the fibers brittle behavior.
- IV 0.51
- the spherical particle shape was understandable since the semirigid-rod geometry of the TR-4 segments caused them to align side by side in elongated LCP-b-PBT domains.
- the LCP- b-PBT domains were ultrafinely and uniformly dispersed and from 0.05 ⁇ m to 0.1 ⁇ m in size. These data suggest that the LCP-b-PBT was not miscible with the PBT but that the adhesion of the LCP-b-PBT domains to the matrix was excellent. It seemed that the undrawn fibers spun at 245°C had somewhat poorly oriented morphology, while those spun at 255°C consisted of well oriented smooth fibrils. Well developed fibrils could not be observed in this blend system except at higher draw ratio.
- the values of the ⁇ versus the LCP-b-PBT content were also compared.
- the tensile strength of the 245°C extruded materials increased from 59 MPa for the PBT fiber with a draw ratio of 40 to 104 MPa for the 20% LCP-b-PBT fiber with the same draw ratio.
- ⁇ was improved from 60 MPa for PBT to 120 MPa for 20% LCP-b-PBT fiber with the same draw ratio of 40.
- the values were about twice that for pure PBT.
- the following Table shows the LCP-b-PBT composition dependence of tensile strength (MPa) of the blend fibers spun at 245°C for a draw ratio of l, 10, 20, and 40: Tensile Str. (MPa) at Draw Ratio of 1 10 20 40
- the following Table shows the tensile strength (MPa) of LCP-b-PBT/PBT (20/80 w/w) blends versus draw ratio when extruded at 245°C and 255°C.
- Fibers made from blends of LCP-b- PBT and PBT generally have shown that tensile strength and _, 30 initial modulus increase with processing temperature.
- the initial moduli for 20% LCP-b-PBT fibers extruded at 245°C and 255°C were 13.0 GPa and 14.2 GPa amounting to an increase of 6 to 7 times that for pure PBT.
- the mechanical properties of the fibers spun through a capillary die increased with draw ratio, processing temperature and LCP-b-PBT content.
Landscapes
- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Polyesters Or Polycarbonates (AREA)
- Compositions Of Macromolecular Compounds (AREA)
Abstract
Description
Claims
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US72660091A | 1991-07-08 | 1991-07-08 | |
PCT/US1992/005670 WO1993001238A1 (en) | 1991-07-08 | 1992-07-07 | Blend of flexible coil polymer and thermotropic liquid crystal segmented block copolymer |
US726600 | 1996-10-07 |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0593664A1 EP0593664A1 (en) | 1994-04-27 |
EP0593664A4 true EP0593664A4 (en) | 1994-06-15 |
Family
ID=24919263
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP19920915938 Withdrawn EP0593664A4 (en) | 1991-07-08 | 1992-07-07 | Blend of flexible coil polymer and thermotropic liquid crystal segmented block copolymer |
Country Status (4)
Country | Link |
---|---|
EP (1) | EP0593664A4 (en) |
JP (1) | JPH06508879A (en) |
CA (1) | CA2113114A1 (en) |
WO (1) | WO1993001238A1 (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5508338A (en) * | 1994-09-20 | 1996-04-16 | Akzo Nobel Nv | Compatibilized blend of polycarbonate, polyester and liquid crystalline additive |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5465747A (en) * | 1977-11-04 | 1979-05-26 | Motoo Takayanagi | High molecular composite body |
JP2505411B2 (en) * | 1986-03-24 | 1996-06-12 | ポリプラスチックス 株式会社 | Resin composition exhibiting anisotropy when melted |
-
1992
- 1992-07-07 EP EP19920915938 patent/EP0593664A4/en not_active Withdrawn
- 1992-07-07 JP JP5502375A patent/JPH06508879A/en active Pending
- 1992-07-07 WO PCT/US1992/005670 patent/WO1993001238A1/en not_active Application Discontinuation
- 1992-07-07 CA CA 2113114 patent/CA2113114A1/en not_active Abandoned
Non-Patent Citations (2)
Title |
---|
No further relevant documents disclosed * |
See also references of WO9301238A1 * |
Also Published As
Publication number | Publication date |
---|---|
EP0593664A1 (en) | 1994-04-27 |
JPH06508879A (en) | 1994-10-06 |
WO1993001238A1 (en) | 1993-01-21 |
CA2113114A1 (en) | 1993-01-21 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP0593592B1 (en) | Thermotropic liquid crystal segmented block copolymer | |
Dobb et al. | Properties and applications of liquid-crystalline main-chain polymers | |
EP0154065B1 (en) | Blend of polyalkylene terephthalate and high molecular weight wholly aromatic polyester and process for producing the same | |
EP0169947B1 (en) | Melt blend of non-thermotropic and thermotropic wholly aromatic polyesters | |
Miller et al. | Fibres from polypropylene and liquid-crystal polymer blends using compatibilizing agents: 1. Assessment of functional and non-functional polypropylene—acrylic acid compatibilizers | |
Kyotani et al. | Mechanical and structural properties of extruded strands of blends containing a liquid-crystalline polyester with poly (ethylene terephthalate) | |
CA1188847A (en) | Aromatic, melt-processible (co)polyesters | |
JPH06341014A (en) | Pulp-like staple fiber of liquid crystal polyester | |
JP3227729B2 (en) | Method for producing resin composition molded article | |
EP0102719A1 (en) | Wholly aromatic polyesters comprising 6-oxy-2-naphthoyl moiety and 4-oxy-4'-carboxy biphenyl moiety | |
Kim et al. | Effect of composition and molecular structure on the LC phase of PHB‐PEN‐PET ternary blend | |
DE60017068T2 (en) | A process for producing high elongation amorphous anisotropic melt-forming polymers and polymers prepared by this process | |
Jackson Jr | Liquid Crystal Polymers: VI. Liquid Crystalline Polyesters of Substituted Hydroquinones | |
Michael et al. | Fibers from Naphthalene-Based Thermotropic Liquid Crystalline Copolyesters | |
EP0593664A4 (en) | Blend of flexible coil polymer and thermotropic liquid crystal segmented block copolymer | |
Chang et al. | Blends of thermotropic liquid crystalline polyesters and poly (butylene terephthalate): Thermal, mechanical, and morphological properties | |
Zhou et al. | Rheological properties of thermotropic liquid crystalline aromatic copolyesters | |
Joslin et al. | Thermotropic liquid-crystalline polymers with flexible moieties blended with poly (ethylene terephthalate) | |
Chang et al. | The effect of composition on thermal, mechanical, and morphological properties of thermotropic liquid crystalline polyester with alkyl side‐group and polycarbonate blends | |
Kim et al. | Studies on the ternary blends of liquid crystalline polymer and polyesters | |
Haderlein et al. | Synthesis and properties of liquid crystalline aromatic copolyesters with lactide moieties | |
Grasser et al. | Thermotropic liquid crystalline copolyesters with non-coplanar biphenylene units tailored for blend fiber processing with PET | |
Su et al. | Preparation and hydrolytic degradation of poly (hexylene terephthalate-co-lactide) co-polyesters from melting polycondensation | |
JP3457000B2 (en) | Thermochromic poly (ester amide) containing monomer units derived from 4,4'-biphenyldicarboxylic acid | |
JPH0446971B2 (en) |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
17P | Request for examination filed |
Effective date: 19940107 |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): CH DE ES FR GB IT LI LU NL |
|
A4 | Supplementary search report drawn up and despatched |
Effective date: 19940427 |
|
AK | Designated contracting states |
Kind code of ref document: A4 Designated state(s): CH DE ES FR GB IT LI LU NL |
|
17Q | First examination report despatched |
Effective date: 19951030 |
|
GRAG | Despatch of communication of intention to grant |
Free format text: ORIGINAL CODE: EPIDOS AGRA |
|
GRAG | Despatch of communication of intention to grant |
Free format text: ORIGINAL CODE: EPIDOS AGRA |
|
GRAH | Despatch of communication of intention to grant a patent |
Free format text: ORIGINAL CODE: EPIDOS IGRA |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN |
|
18D | Application deemed to be withdrawn |
Effective date: 19981006 |