Use Of Polyester Research Articles

Closed-loop utilization of polyester in the textile industry

An efficient decolorization strategy for waste polyester textiles and a new purification strategy for the glycolysis product were developed and combined to enable the repeatable use of polyester in the textile industry.

Characterization Of Jute/Aramid Hybrid Composite Materials with Using Different Resins

For the last twenty to thirty years, interest in the use of hybrid fiber-reinforced composites has gradually increased due to their potential for various applications. The balanced strength and stiffness properties of hybrid composites, along with the advantages of lighter weight and lower cost, have made them an important step toward replacing traditional materials. In this study, a hybrid composite was made from a combination of Jute fabric from natural fibers, Aramid fabric from synthetic fibers, and two different resins (polyester and vinylester). This type of study was proposed because there is little research in the literature on how the use of polyester and vinyl ester resins affects the mechanical properties of homogeneous composites and hybrid composites. The vacuum assisted resin transfer molding process was used for the fabrication. The mechanical properties of the manufactured products were determined by tensile and hardness tests, and their morphological structures were examined by taking scanning electron microscope images. The results indicate that the value of tensile strength and elastic modulus of the Jute/Aramid hybrid samples in the productions prepared with polyester resin is 37.6% and %12.28, respectively, higher than in those made with vinyl ester resin. When comparing the values for microhardness, the results of the Jute/Aramid hybrid specimens produced with polyester resin were 1.20 times higher than those produced with vinyl ester resin. Scanning electron microscope images of the samples also clearly show that the bonding between matrix and fiber is better in polyester resin samples.

Electrochemical paper-based devices: When the simple replacement of the support to print ecodesigned electrodes radically improves the features of the electrochemical devices

Paper-based electrochemical (bio)sensors have emerged as highly attractive analytical devices for their superior sustainable features, such as avoiding the use of polyester as support and the reduction of waste, being incinerated after use. However, paper-based electrochemical (bio)sensors have recently demonstrated further advantages, including the simple combination with vertical microfluidics and their use as a reservoir to deliver smart electrochemical (bio)sensors able to i) contain the reagents, ii) preconcentrate the target analyte, and iii) synthesize the nanomaterials inside the paper network. Furthermore, these devices have demonstrated their ability to overcome the limitations of the other printed electrochemical sensors in the measurement of entirely liquid samples by detecting the target analyte in the aerosol phase or solid sample, without the additional sampling system. These achievements highlight their valuable and varied advantages in the sensing sector. • Paper-based electrochemical sensors to preconcentrate the target analyte. • Paper as reactor to synthesize the nanomaterials delivering nanomaterial-decorated devices. • Paper-based electrochemical sensors for detection in aerosol phase or in solid sample. • Reagent-free electrochemical devices.

EFFECT OF FROST ON GERMPLASM USED IN RESTORATION OF DEGRADED AREA IN THE SERRA DO ITAJAÍ NATIONAL PARK

Frosts that occur in the Southern Brazil limit the development and survival of seedlings used for restoration projects and may cause significant losses. The objectives of this study were: evaluating the effect of frosts on seedlings produced by seeds collected around a degraded area inside the Serra do Itajaí National Park (PNSI) and used to restore this area; and validating the use of polyester printed labels for marking seedlings. Planting was carried out in adapted Anderson Groups, with 25 seedlings per module. Survival rates for frost were evaluated in 750 seedlings, identified at the species level, classified according to their ecological group, and used in three areas designated as A, B and C. 80% of the seedlings were planted in sloping area and 20%, in lowland area. For the identification of the seedlings, labels printed by a laser printer were used on matte polyester film and affixed with plastic polyamide clamps. This method proved to be practical, inexpensive and resistant to the climate action (heat, humidity and precipitation). Besides, it does not suffer attacks from the local fauna. The overall survival rate was 55.87%, whereas survival rates by ecological groups were 76.67% for shadow tolerant climax, 53.75% for light demanding climax, and 55.63% for the pioneer. The highest survival rates were the ones from seedlings located on the slopes. It was possible to verify that the local germplasm is well adapted to the frosts that occur in the region.

Pancreaticojejunostomy after Pancreaticoduodenectomy: Suture Material and Incidence of Post-Operative Pancreatic Fistula

Abstract Purpose Pancreatic fistula represents the most important complication in terms of clinical management and costs after pancreaticoduodenectomy. A lot of studies have investigated several techniques in order to reduce pancreatic fistula, but data on the effect of sutures material on pancreatic fistula are not available. The analysis investigated the role of suture material in influencing pancreatic fistula rate and severity. Methods Results from 130 consecutive pancreaticoduodenectomy with pancreaticojejunostomy performed between March 2013 and September 2014 were prospectively collected and analyzed. In 65 cases pancreaticojejunostomy was performed with absorbable sutures, in the other 65 cases using non-absorbable sutures (polyester, silk and polybutester). Results Pancreaticojejunostomy with non-absorbable sutures had the same incidence of pancreatic fistula, but less severe and with less episodes of post-operative bleeding if compared with absorbable sutures. A sub-analysis was carried out comparing polydioxanone with polyester: the latter was associated with a lower pancreatic fistula rate (11.9% vs. 31.7%; p = 0,01) and less severe pancreatic anastomosis dehiscence (grade C - 0% vs. 30%; p = 0.05). Univariate and multivariate analysis confirmed that hard pancreatic texture, pancreatic ductal adenocarcinoma at final histology and the use of polyester for pancreaticojejunostomy were associated with a lower pancreatic fistula rate (p Conclusion Further studies are needed to investigate the effects of pancreatic juice and bile on different sutures and pancreatic tissue response to different materials. However, pancreaticojejunostomy performed with polyester sutures is safe and feasible and is associated to a lower incidence of pancreatic fistula with less severe clinical impact.

Pancreaticojejunostomy after pancreaticoduodenectomy: Suture material and incidence of post-operative pancreatic fistula.

Pancreatic fistula represents the most important complication in terms of clinical management and costs after pancreaticoduodenectomy. A lot of studies have investigated several techniques in order to reduce pancreatic fistula, but data on the effect of sutures material on pancreatic fistula are not available. The analysis investigated the role of suture material in influencing pancreatic fistula rate and severity. Results from 130 consecutive pancreaticoduodenectomy with pancreaticojejunostomy performed between March 2013 and September 2014 were prospectively collected and analyzed. In 65 cases pancreaticojejunostomy was performed with absorbable sutures, in the other 65 cases using non-absorbable sutures (polyester, silk and polybutester). Pancreaticojejunostomy with non-absorbable sutures had the same incidence of pancreatic fistula, but less severe and with less episodes of post-operative bleeding if compared with absorbable sutures. A sub-analysis was carried out comparing polydioxanone with polyester: the latter was associated with a lower pancreatic fistula rate (11.9% vs. 31.7%; p = 0,01) and less severe pancreatic anastomosis dehiscence (grade C - 0% vs. 30%; p = 0.05). Univariate and multivariate analysis confirmed that hard pancreatic texture, pancreatic ductal adenocarcinoma at final histology and the use of polyester for pancreaticojejunostomy were associated with a lower pancreatic fistula rate (p < 0.05). Further studies are needed to investigate the effects of pancreatic juice and bile on different sutures and pancreatic tissue response to different materials. However, pancreaticojejunostomy performed with polyester sutures is safe and feasible and is associated to a lower incidence of pancreatic fistula with less severe clinical impact.

Comparative study between meshes of polyester with collagen and polytetrafluoroethylene in the repair of defects produced in abdominal wall of rats

To study the intraperitoneal use of polyester with collagen and polytetrafluoroethylene meshes in the correction of total ventral wall defects in rats. Thirty two rats were evaluated and divided randomly into four groups and underwent laparotomy and preparation of total defects of the abdominal wall. Next, the correction of the defect with the intraperitoneal placement of the chosen mesh was performed. The rats were submitted to euthanasia at 30 and 90 days after surgery. Were analyzed the macroscopic adhesions and microscopic aspects, and applied stress rupture test All animals showed intraperitoneal adhesions in varying degrees, with no statistical significance difference. There was no difference also between groups in the evaluation of stress rupture tests. On the microscopic aspect, the A30 group had less inflammatory reaction and less formation of granulomas and foreign body reaction that the B30 group, with significant difference. There was no difference in intraperitoneal adhesion and tensile rupture strength among groups. Group B30 presented granulomatous inflammatory reaction at the site of mesh attachment to the wall significantly higher than the A30.

Synthesis of azo pyridone dyes

Over 50% of all colorants which are used nowdays are azo dyes and pigments, and among them arylazo pyridone dyes (and pigments) have became of interest in last several decades due to the high molar extinction coefficient, and the medium to high light and wet fastness properties. They find application generally as disperse dyes. The importance of disperse dyes increased in the 1970s and 1980s due to the use of polyester and nylon as the main synthetic fibers. Also, disperse dyes were used rapidly since 1970 in inks for the heat-transfer printing of polyester. The main synthetic route for the preparation of azo dyes is coupling reaction between an aromatic diazo compound and a coupling component. Of all dyes manufactured, about 60% are produced by this reaction. Arylazo pyridone dyes can be prepared from pyridone moiety as a coupling component, where substituent can be on nitrogen, and diazonim salts which can be derived from different substituted anilines or other heterocyclic derivatives. In addition, arylazo dyes containing pyridone ring can be prepared from arylazo diketones or arylazo ketoesters (obtained by coupling ?-diketones or ?-ketoesters with diazonim salts) by condensation with cyanoacetamide. Disazo dyes can be prepared by tetrazotizing a dianiline and coupling it with a pyridone or by diazotizing aniline and coupling it with a dipyridone. Trisazo dyes can be also prepared by diazotizing of aniline and coupling it with a tripyridone or by hexazotizing a trianiline and coupling it with a pyridone. The main goal of this paper is to give a brief review on the synthesis of arylazo pyridone dyes due to the lack of such reviews. In addition, some properties of arylazo pyridone dyes as light fastness and azo-hydrazon tautomerism are disccused.

Confirmation of Biologic Ingrowth into a Polyester Matrix in the Endometrial Cavity in an Animal Model

Study Objective: To determine the ability to achieve biologic ingrowth into a polyester matrix in the endometrial cavity in an animal model. The purpose of this is to allow further investigation into the use of polyester to promote biologic ingrowth into the endomyometrium near the uterotubal junction for sterilization purposes. Design: Devices were inserted into four Nubian goats on the same day. Because of anatomic differences from the human model, the devices could not be placed transcervically. A device was placed in each horn via a small hysterotomy incision and secured with non-reactive suture material. The animals were recovered. The uterus was removed from a goat on each of the successive four weeks. The uteri were sent to a pathology lab with expertise in staining for biologic ingrowth. Serial sections were obtained and stained to determine the degree of biologic ingrowth into the polyester matrix. Setting: The devices were inserted into the animal models in a qualified veterinary surgical facility. Measurements and Main Results: Pathologic determination of progressive biologic ingrowth into the polyester matrix was confirmed. By Week 1, early ingrowth was readily identified. By Week 4, ingrowth of tissue into the polyester matrix was confirmed, with the endometrium essentially replaced by ingrowth. The ingrowth provided contact of the polyester to an depth close to the myometrium. Conclusion: Biologic ingrowth into a polyester matrix can be acheived in the endometrial cavity. With the local destruction of the endometrial layer and ingrowth to a depth approaching the myometrium by Week 4, there should be no concern about the device being expelled during menses. Further investigation into the usefulness of this finding is necessary to determine if the concept can be applied to a transcervical sterilization device.

Comparison between anatomical polyester (Parietex) mesh and polypropylene (Prolene) mesh with fixation in total extraperitoneal repair for inguinal hernia

AbstractIntroduction: Laparoscopic inguinal hernia surgery has been gaining in worldwide popularity, with the total extraperitoneal (TEP) repair gaining greater acceptance than the transabdominal pre‐peritoneal repair. Most techniques using TEP advocate some form of fixation of the prosthesis, but newer meshes avoid the use of fixation.Methods: We compared the use of the polyester mesh (Parietex; Tyco, Princeton, USA) without fixation and polypropylene (Prolene; Ethicon, USA) mesh with fixation using either ProTack (Tyco, USA) or EndoAnchor (Ethicon, Cincinnati, USA) in a consecutive series of patients who underwent total TEP endoscopic inguinal hernia repair.Results: Of 127 patients who underwent TEP repairs, 60 had Parietex mesh while 67 had Prolene mesh with fixation. The mean age was 50 years old and 97% were men. There was no difference in patient demographics or complication rate. The most common complication was small seroma or hematoma formation in 14% of patients and none required re‐operation. There was no hernia recurrence in either group with a mean follow‐up period of 13 months.Conclusion: This study shows that in laparoscopic TEP inguinal hernia repair, early results indicate comparable results between the use of polyester (Parietex) mesh without fixation and polypropylene (Prolene) mesh with fixation.

Socketing of polyester fibre ropes with epoxy resins for deep-water mooring applications

The use of polyester (PET) fibre ropes in mooring applications for deep water oil platforms implies the use of terminations, e.g. the spliced eye, which demands specialized manual labour and is time consuming. This research evaluates the technical viability of substituting these terminations with a resin socketing procedure, which consists of introducing a simple-end rope in a hollow metallic device having a conical shape (i.e. a socket) and pouring into it a thermoset resin that, once cured, fastens the rope extremity. PET ropes (10 or 48 mm diameter) were socketed and evaluated under tensile testing. The curing and viscoelastic behaviour of various epoxy resin systems were monitored with DSC and DMA. The performance of socketed PET ropes was suitable for the intended application, showing failure loads similar to those of unsocketed ropes, being particularly dependant on resin type, socket conicity and resin/fibre volumetric ratio in it.

Problem of recurrent incisional hernia after mesh repair of the abdominal wall

Depending on the surgical technique, mesh material and follow-up, the figures for recurrences of incisional hernia vary from 0 to 31%. What are the reasons for recurrences, and which options exist for more successful therapy? Fourteen operations for recurrences after mesh repair of incisional hernias were analyzed retrospectively and correlated with a literature review of the years 1990-2000. An inadequate surgical technique is the main reason for recurrences after the use of polypropylene or polyester, but with PTFE, it is instead the properties of the material. In our patients we found central mesh recurrences. The first results with laparoscopic technique are very promising. Open incisional hernia mesh repair should be performed with the sublay technique, preferably with polypropylene; the use of polyester can be recommended only with reservations and the use of PTFE ought to be limited to very few indications. The entire incision should always be prepared with safe fixation of the mesh and wide overlap of the hernia. Recurrences after polypropylene implantation can be treated with additional mesh; concerning PTFE, a different material is recommended. A final evaluation of laparoscopic mesh repair cannot be assessed yet.

Fatigue testing median sternotomy closures

Sternal dehiscence is commonly due to wire cutting through bone. With a biological model, we measured the rate of cutting through bone, of standard steel wire closure, peristernal steel wire, figure-of-eight closure, polyester and sternal bands sternotomy closure techniques. Polyester, figure-of-eight, peristernal and sternal band closures were tested against standard closure eight times using adjacent paired samples, to eliminate biological variables. Fatigue testing was performed by a computerized materials-testing machine, cycling between loads of 1 and 10 kg. The displacements at maximum and minimum loads were measured during each cycle. Cutting through, manifested by the displacement at the maximum load between the 1st and 150th cycles was measured. The percentage cut-through of each closure method versus standard closure was calculated. The differences in the displacement between each of the polyester (1.01 mm), figure-of-eight (0.52 mm), peristernal (0.72 mm) and sternal band (0.66 mm) groups versus standard closure (0.22, 0.22, 2.1, 3.2 mm) in the paired samples were statistically significant (Student's paired t-test; P<0.01). There were statistically significant differences in the percentage cut-through of polyester, figure-of-eight, peristernal and sternal bands (ANOVA, P<0.001), versus standard closure. In our sheep sternum model, we have quantified the differing rate of cutting through bone of five types of median sternotomy closure techniques. We have controlled for bone variables by testing each closure versus standard closure using paired adjacent bone samples. Peristernal and sternal band closure techniques are significantly superior to standard closure. The use of polyester and figure-of-eight closures requires caution.

Holographic recording and retrieval of polarized light by use of polyester containing cyanoazobenzene units in the side chain

We examined the holographic recording properties of polyester containing cyanoazobenzene units in the side chain. It was revealed that, when a linearly polarized object beam with an arbitrary polarization direction was recorded, the retrieved beam had the same polarization state as that of the object beam, with a constant diffraction efficiency of 0.1. Moreover, two object beams with mutually orthogonal linear polarization could be recorded and retrieved separately from the same area. This is, to our knowledge, the first example of holographic polarization multiplexing. The retrieved images were found to resolve details of ~40line pairs/mm and a 40-mum -pitched checkerboard pattern. The resolution of the system is limited by the CCD cameras that are used. Polarization encoding to increase the storage capacity and (or) the signal-to-noise ratio of holographic data recording is also discussed.

Block copolymers derived from 2,2′‐azobis(2‐cyanopropanol). I. Synthesis of poly(urethane‐ block ‐methyl methacrylate) and poly(urethane‐ block ‐styrene)

Block copolymers with polyester-urethane and polymethyl methacrylate (PMMA) or polystyrene (PS) sequences were obtained by the use of polyester- or polyether-urethane macroazo initiators (PUMAI). PUMAI with a well-defined number of azo groups per chain were prepared via a two-stage reaction procedure using 2,2'-azobis(2-cyanopropanol) (ACP), 4,4'-methylene diphenyl diisocyanate (MDI) and α,ω-hydroxy polycaprolactone (PCL). The characteristics of the obtained block copolymers depend on the reaction conditions, and a yield of 98% was obtained for a P(U-b-MMA) synthesized with a ratio of macroazo initiator to monomer equal to 1/400. In similar conditions, copolymerization of styrene was more difficult, and the maximum block copolymer yield obtained in this work was only of 37% for a ratio of macroazo initiator to monomer equal to 1/150. Combination of different analyses Fourier transform infrared (FTIR) spectroscopy, proton nuclear magnetic resonance ( 1 H-NMR), and size exclusion chromatography (SEC) carried out on both crude and fractionated copolymers showed this kind of synthesis yielding di- and triblock copolymers and only a little amount of PU homopolymer.

Complications of Mersilene Sutures in Penetrating Keratoplasty

After penetrating keratoplasty, many corneal surgeons adjust sutures to reduce astigmatism and then leave the sutures in place indefinitely. Nylon sutures can hydrolyze and break years after surgery. In a series of human penetrating keratoplasties, we studied the use of polyester (Mersilene) sutures that do not hydrolyze. We performed two prospective studies of polyester (Mersilene) sutures in human penetrating keratoplasty done by one surgeon. Study I was a randomized comparison of combined running and interrupted Mersilene and nylon sutures in 45 consecutive eyes. Study II was a case series of single running Mersilene suture with postoperative adjustment of suture tension to manage astigmatism in 23 consecutive eyes. We evaluated the performance of the suture and the control of astigmatism. The interrupted running suture study demonstrated that interrupted Mersilene sutures were 5.5 times more likely to have handling-related complications than nylon interrupted sutures (p = .01); in addition, they were three times as likely to have tissue-related complications as nylon (p = .16). The running suture study demonstrated an unacceptable complication rate of 69% when Mersilene was used as a single adjustable running suture. At 6 months postoperatively, the median refractive astigmatism for the adjustable cases was 3.37 diopters (mean, 4.03 +/- 2.37 D). Eyes with significant suture-related complications were 2.85 times more likely to have greater than 4.00 D of refractive astigmatism than were eyes without suture-related complications. Mersilene is an undesirable suture for use in penetrating keratoplasty.

Rowcovers Accelerate Fruiting and Increase Productivity in Primocane-fruiting Red Raspberries

Studies were conducted over eight location-years to evaluate the effects of rowcover material, time of application, and time of removal on `Heritage' red raspberry cane growth, flowering, and fruiting. We anticipated that rowcovers would accelerate fruit maturity so that more of the crop could be harvested before the onset of cold temperatures in autumn. In seven of the eight experiments, rowcovers either increased yields or accelerated harvest. With a March application, harvest began 3 weeks earlier, and August yields of covered plants were 42 times higher than those of noncovered plants. Responses were observed with spunbonded polypropylene and polyester covers, but not with polyethylene covers. Rowcovers placed over the row before primocane emergence and removed when canes were ≈50 cm tall resulted in the greatest plant response. The use of polyester or polypropylene rowcovers with primocane-fruiting raspberries appears to be economically feasible in most years in northern climates.

Gas purity requirements for titanium silicide metalization : Henry Berger. Semiconductor int., 137 (September 1987)

The use of polyester (PET) fibre ropes in mooring applications for deep water oil platforms implies the use of terminations, e.g. the spliced eye, which demands specialized manual labour and is time consuming. This research evaluates the technical viability of substituting these terminations with a resin socketing procedure, which consists of introducing a simple-end rope in a hollow metallic device having a conical shape (i.e. a socket) and pouring into it a thermoset resin that, once cured, fastens the rope extremity. PET ropes (10 or 48 mm diameter) were socketed and evaluated under tensile testing. The curing and viscoelastic behaviour of various epoxy resin systems were monitored with DSC and DMA. The performance of socketed PET ropes was suitable for the intended application, showing failure loads similar to those of unsocketed ropes, being particularly dependant on resin type, socket conicity and resin/fibre volumetric ratio in it.

Electrical modeling of interconnections in multilayer packaging structures : Algierd A. Palusinski, J. C. Liao, Paul E. Teschan, John L. Prince and Francisco Quintero. IEEE Trans. Compon. Hybrids mfg Technol.CHMT-10, 217 (1987)

The use of polyester (PET) fibre ropes in mooring applications for deep water oil platforms implies the use of terminations, e.g. the spliced eye, which demands specialized manual labour and is time consuming. This research evaluates the technical viability of substituting these terminations with a resin socketing procedure, which consists of introducing a simple-end rope in a hollow metallic device having a conical shape (i.e. a socket) and pouring into it a thermoset resin that, once cured, fastens the rope extremity. PET ropes (10 or 48 mm diameter) were socketed and evaluated under tensile testing. The curing and viscoelastic behaviour of various epoxy resin systems were monitored with DSC and DMA. The performance of socketed PET ropes was suitable for the intended application, showing failure loads similar to those of unsocketed ropes, being particularly dependant on resin type, socket conicity and resin/fibre volumetric ratio in it.

Woven Fabrics for Coating and Laminating

Woven fabrics continue to dominate as coating and laminating substrates, offering great flexibility and a wide variety of properties. This paper reviews the development and contribution of various fibers, particularly polyester and nylon; the role of different yarn types: the affect and attributes of various weaves; and the role of new weaving equipment. Even greater use of polyester, the emergence of polypropylene as a substrate fiber, and greater use of textured yarns are presented as trends. The point is stressed that if we are to survive and prosper in the face of imports, we must be innovative, creative leaders, not followers.