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Objective To develop and validate a new measure of cancer knowledge for members of the general population who have never been diagnosed with cancer. Methods Initially, 20 items were generated to measure cancer knowledge. After expert refinement and cognitive interviews, 11 items remained and were completed by 1,076 adults with no history of cancer. Responses were assessed using an item response theory (IRT) approach and differential item functioning. Results Items were analyzed using a two-parameter logistic IRT model. Two items with tetrachoric correlation coefficients>0.8 and one item with a discrimination parameter>2.0 were excluded. The final eight items demonstrated a good range of discrimination (1.13 to 1.86) and difficulty (−1.11 to 0.85). No meaningful differential item functioning by participant attributes was detected for these eight items. Conclusion The Cancer Knowledge Scale appears to be a reliable and valid measure for the general population. Practice Implications The eight-item scale could be used to assess the effects of psychoeducational programs, including those on cancer knowledge, for members of the general population with no cancer history

Academic educators in universities are well positioned to detect early signs and symptoms of unexplained behaviour change in students that could be the beginning of mental health issues. The purpose of this research was to explore the attitudes, beliefs, knowledge and practices of university academics in Japan towards health science students with psychological/mental health issues. This study used a qualitative descriptive design. Three focus groups using a semi-structured interview guide were conducted with 15 academics teaching health science students. Data were collected between March to October 2019. Themes revealed three areas of interest: 1) Reflection on mental health issues in Japan with sub-themes "family issues"; "society expectations and changes", and "stigma"; 2) Reflection on students' mental health issues with sub-themes "student behaviors", "staff involvement", "barriers encountered"; and, 3) Potential supports with sub-themes "university assistance", "communication and connection", and "interventions and prevention." The findings provide insight and can benefit student populations across diverse cultural university settings. Further research to investigate academic staff support with early recognition of mental ill-health and ability to provide information and advice to students is warranted. Recommendations include mental health education for academics and for students to encourage healthy university campuses and well-being within the community.

Objective: This study explored the factors influencing commissioned welfare volunteers' (CWVs) attitudes toward mental illnesses and how their attitudes correlated with their social distance from people with mental illness. Materials and Methods: Data from 223 CWVs were analyzed statistically. Factor extractions for the Image for Mental Illness Scale (IMI) and Social Distance Scale (SDS) were calculated. We examined the relations between factors in IMI and SDS. Results: CWVs' attitudes were classified as Understanding (understanding of the condition), Secure (feelings of safety in the presence of those with mental illness), and Activity (reactions to the behaviors of people with mental illness). Social distance from those with mental illness was classified as Public and Private Interactions. CWVs' interactions with people with mental illness were significantly influenced by feeling Secure in the presence of the latter. Low Public and Private Interactions were influenced by older age. CWVs' "experience in providing consultations for mental illness" led to the avoidance of Private Interactions. Conclusion: CWVs should feel safe when involved in Public or Private Interactions with individuals with mental illness. CWVs reported a preference for a higher level of social distance from people with mental illness.

The aim of this study is to enrich nursing education by clarifying the relationship between personality traits, motivation, and career paths in professional nursing. This cross-sectional study surveyed 150 nurses from a polyclinic in Japan that performs internal medicine and surgery. The survey covered several aspects of personality, work motivation, and career development using the Ten-Item Personality Inventory, Work Motivation Scale, and Nurses' Job Career Scale. The demographics of the participants were also recorded. Multiple regression analysis revealed that the personality traits extraversion and agreeableness had a direct and positive impact on nurses' interest in team collaboration, but not on career development. Interest in career improvement was related to conscientiousness as a power toward purpose and openness as an aspect of curiosity. Conscientiousness and openness were indirectly related to the development and adjustment of interpersonal relationships and self-capability development through interest in career improvement. Interest in patient support positively impacted the implementation and pursuit of quality nursing. The findings highlight the need to account for individual differences in personality and motivation to support nurses' success during their nursing education and in the workplace.

ObjectivesTo develop the Psychiatric Nurse Self-Efficacy Scales, and to examine their reliability and validity.DesignWe developed the Improved Self-Efficacy Scale (ISES) and Decreased Self-Efficacy Scale (DSES) using existing evidence. Statistical analysis was conducted on the data to test reliability and validity.SettingThe study’s setting was psychiatric facilities in three prefectures in Japan.ParticipantsData from 514 valid responses were extracted of the 786 responses by psychiatric nurses.Outcome measuresThe study measured the reliability and validity of the scales.ResultsThe ISES has two factors (‘Positive changes in the patient’ and ‘Prospect of continuing in psychiatric nursing’) and the DSES has three (‘Devaluation of own role as a psychiatric nurse’, ‘Decrease in nursing ability due to overload’ and ‘Difficulty in seeing any results in psychiatric nursing’). With regard to scale reliability, the Cronbach’s alpha coefficient was 0.634–0.845. With regard to scale validity, as the factorial validity of the ISES and DSES, for the ISES, χ2/df (110.625/37) ratio=2.990 (p2/df (101.982/37) ratio=2.756 (pStatistical analyses showed the scales to be reliable and valid measures.ConclusionsThe ISES and DSES can accurately assess psychiatric nurses’ self-efficacy. Using these scales, it is possible to formulate programmes for improving psychiatric nurses’ feelings of self-efficacy.

Objective: This study aimed to clarify the process of students’ experience of learning to identify association and dissociation between lectures and practicums in psychiatric and mental health nursing (PMHN) education at a university.Methods: An interview survey of 21 students from a regional national university in Japan was conducted, and the interview data were analyzed with a modified grounded theory approach.Results: The analysis identified 12 categories and 32 concepts regarding the process of learning experience in PMHN among university nursing students. Through lectures, the students accomplished “self-developmental knowledge retention” or “acquisition of superficial knowledge about PMHN” toward “formation of learning attitude based on life experience.” The outcomes of lectures significantly affected practicums; the former possibly resulted in “non-discovery of significance of practicums;” however, the latter possibly approached “developmental self-learning.”Discussion: The association between students’ interests based on life experience and contents of lectures affected practicums, and the lecture design readily imaginable from students’ experience was desirable. Practicums must be built on teaching strategies that make students aware of the particularity of communication.

Objective To determine the factors associated with the degree of distress experienced by patients with cancer before disclosing their cancer diagnosis to a friend and their perceptions of social support upon disclosure. Methods Adult patients with cancer participated in a cross-sectional Internet-based survey on their behaviour when disclosing their diagnosis to a selected friend, degree of distress before this disclosure and perceived social support upon disclosure. Results Of 473 eligible respondents, around half were middle-aged (40-59 years) and around half were men. Having a younger age (20-39 years), being a woman and delaying disclosure were factors associated with greater pre-disclosure distress. Most participants perceived receiving emotional support upon disclosure. Telling a close friend or a female friend and early disclosure timing were associated with perceived social support, although this varied by social support type. Conclusion Younger patients and women may need more support in deciding to disclose their cancer diagnosis to friends. Selection of to whom to disclose this information and disclosure timing should be considered to achieve more desirable outcomes. In addition to selective disclosure-including planning and scheduling-communication skills may be required for effectively disclosing a cancer diagnosis and achieving favourable results following this disclosure.

The average length of hospital stay in the psychiatric ward is longer, and the risk of patient-to-nurse violence is higher than that in other departments. Therefore, psychiatric nurses’ work environment may differ from that of other nurses. The factors related to psychiatric nurses’ self-efficacy may also differ from those of general workers or other nurses. Mental health care that considers the characteristics of psychiatric nurses requires exploration of self-efficacy unique to psychiatric nurses. This cross-sectional study aimed to explore the distinct factors related to psychiatric nurses’ self-efficacy. The developed 24 items related to improvement in self-efficacy and 25 items related to decrease in self-efficacy were examined. The Generalized Self-Efficacy Scale was used to measure the validity of the factors. To extract the factors of self-efficacy, data from 132 nurses and assistant nurses who provided informed consent were analyzed, and the reliability and validity of the factors were calculated. The factors associated with improvement in self-efficacy were “Positive reactions by patients,” “Ability to positively change nurse-patient relationship,” and “Practicability of appropriate nursing.” The factors associated with decrease in self-efficacy were “Uncertainty in psychiatric nursing” and “Nurses’ role loss.” The Cronbach’s α for all factors exceeded .70. Of the five factors, four had significant weak-to-moderate correlations with the Japanese version of the Generalized Self-Efficacy Scale; therefore, the validity was quantitatively confirmed with four factors. Interventions based on these four factors may improve psychiatric nurses’ self-efficacy. Additionally, it is possible that this tool assesses the unique facets of self-efficacy rather than psychiatric nurses’ general self-efficacy. Interventions to improve psychiatric nurses’ self-efficacy based on the characteristics of psychiatry are needed.

Objectives: The present study was aimed at constructing the Japanese version of the Brief Illness Perception Questionnaire for breast cancer (Brief IPQ-JBC), for use with Japanese middleand early old-aged women who had not previously undergone mammography. We also examined the psychometric properties of the translated instrument. Methods: Patients were 824 middleand early old-aged women living in all parts of Japan, who Original Research Article Adachi et al.; BJMMR, 5(12): 1491-1501, 2015; Article no.BJMMR.2015.169 1492 completed surveys on the Internet in January 2014. Of these, 282 had not previously undergone mammography and were included in this study, completing the Internet survey again, six months later, in July 2014.The participants were evaluated on the basis of a battery of questionnaires comprising demographic details, the tentative version of the Brief IPQ-JBC, the Japanese version of the Illness Perception Questionnaire (J-IPQ), Self-Directedness subscale from the Japanese version of the Temperament and Character Inventory-125 items, perceived breast cancer risk, and anticipated worry about breast cancer. Results: The Brief IPQ-JBC was found to have good long-term test-retest reliability, as well as concurrent validity with the J-IPQ. The scale also showed good construct validity, based on the results of a path model using structural equation modeling, thus supporting the theoretical perspective of the common-sense model of self-regulation. Conclusion: We have validated the Brief-JBC in a sample of Japanese middleand earlyold-aged women and believe our results will be useful for subsequent research.

Psychological mindedness (PM) is a psychological construct that represents the tendency and ability to understand the relationships between thoughts, feelings, and behavior. This study examined the statistical properties, particularly the factor structure, of the Psychological Mindedness Scale (PMS) in a non-clinical Japanese sample through exploratory and confirmatory factor analysis. The relationship between PMS and depression was also examined for predictive validity. The results suggested that the PMS tested on a Japanese sample contains the following four factors: (a) belief in the benefits of discussing one's problems; (b) access to feelings; (c) openness to new ideas and capacity to change; and (d) interest in the meaning and motivation of own and others' behavior. Whereas the total PM score and Factors 2 and 3 had negative correlations with depression, there was a positive correlation between Factor 4 and depression. The 4-factor structure of the scale is deemed to be applicable to the Japanese population.

Few studies in Japan have examined whether children's later mental health is influenced by the way parental authority is exercised, specifically with a focus on gender. Our main purposes of this study were to confirm the three-factor structure of the Japanese version of the Parental Authority Questionnaire (PAQ) and to verify its reliability and validity. We then used structural equation modeling to examine whether children's later mental health was influenced by parents' authoritative, permissive, and authoritarian parenting. The subcategories included in the Japanese version of the Clinical Outcomes in Routine Evaluation-Outcome Measure were chosen as mental health indices. A total of 1,320 people in Japan, including company employees, university students, and hospital staff members, were asked to recall and evaluate the parenting they received and to report on their current mental health. Confirmatory factor analyses verified the three-factor structure of the Japanese version of the PAQ, with a reduction in the number of items from the original version. The respondents, regardless of gender, evaluated their mothers as having been more authoritative than their fathers. Concerning the impact of parenting styles on respondents' later mental health, both maternal and pater- nal authoritarian parenting styles worsened respondents' later mental health, including symptomatic problems, risk to self and others, life functioning, and psychological well- being. Both maternal and paternal authoritative parenting had a beneficial impact on respondents' later mental health. Simultaneous analyses of multi-groups demonstrated that the nature of these influences did not vary with respondent gender. We present the above results in detail, and discuss them from psycho-socio-cultural viewpoints.

Previous Dependency Inventory (JIDI) as well demonstrates how the interpersonal attitudes assessed by the JIDI generate interpersonal negative life events (NLEs) and therefore results in dysphoric moods and poor life functioning. The subjects of this study were 467 Japanese university students. The JIDI was administered at Time 1, and the Clinical Outcomes in Routine Evaluation-Outcome Measure (CORE-OM) was administered at Time 2 for the purpose of assessing dysphoric mood and life functioning. NLEs occurring between Times 1 and 2 were evaluated. The three-factor structure of the JIDI was confirmed by confirmatory factor analysis. The structural equation modeling demonstrated that of the three factors, only one, “emotional reliance”, predisposed individuals to dysphoric mood and poor life functioning, both directly and indirectly, via interpersonal NLEs. Although the other two factors did not increase vulnerability to interpersonal NLEs or dysphoric mood, “lack of social self-confidence” worsened general functioning, and “assertion of autonomy” led to poor functioning in close relationships, both directly. Furthermore, “assertion of autonomy” decreased anxiety levels. As to gender differences, simultaneous analysis of multi-groups showed that female subjects were more likely to become anxious following interpersonal NLEs.

We examined the psychosocial factors affecting middle-aged Japanese women’s intentions to undergo mammography, as well as their actual usage of mammography by applying the Parallel Processing Model (PPM) of self regulation longitudinally. A total of 1030 middle-aged women living in all parts of Japan participated in this study through internet research from September 2010 to May 2011. The participants were evaluated on the basis of a battery of questionnaires mainly including demographics, perceived breast cancer risk, worry about breast cancer, mammography testing beliefs, intentions to use mammography, seeking information about mammography, and actual usage of mammography thrice over an eight-month period. The main results were as follows: 1) Perceived risk and cancer worry affected the intention of undergoing mammography, and this effect was mediated by beliefs about mammography testing. 2) Intention to use mammography and past mammography usage predicted future usage of mammography, with past mammography usage being the strongest predictor. 3) Information seeking about mammography was the strongest predictor of using mammography during the eight-month follow-up period of middle-aged women who had not undergone any mammography testing. PPM was a useful model to explain the mechanism behind middle-aged Japanese women’s intentions to use mammography, as well as their actual usage of mammography. In addition, past mammography experience was the strongest predictor of regular mammography usage and information seeking was a critical factor for the first-usage of mammography.

This study examined the reliability and validity of the Japanese version of the Clinical Outcomes in Routine Evaluation–Outcome Measure (CORE-OM), a standardized, brief, but comprehensive outcome measurement. The target population consisted of 1684 Japanese company employees, hospital staff, and university students. A confirmatory factor analysis proved that our data fit the factor structure of the original CORE-OM. We also examined its internal consistency, test-retest reliability, convergent validity, and sensitivity in discriminating between clinical and nonclinical samples. After demonstrating these results, we discuss how the Japanese version of the CORE-OM can be used both in clinical and research settings. © 2011 Elsevier Inc. All rights reserved.

Objective: We conducted an empirical study to clarify how psychosocial factors (e.g. body image and sexuality) influence therapeutic decision-making and to identify the factors that affect post-operative mood states in Japanese women who underwent various types of surgery. Methods: One hundred and two patients who had undergone surgical treatment for breast cancer participated in this study. Twenty-five patients had undergone mastectomy, 67 breast conserving treatment and 11 skin-sparing mastectomy and immediate breast reconstruction. The participants were evaluated based on a battery of questionnaires including value estimates of decision-making factors, a shortened version of the Profile of Mood States and selfefficacy. Results: The patients regarded the possibility of cure and recurrence of cancer as well as the physician’s support as important, regardless of the treatments they had chosen. The patients that had immediate breast reconstruction placed significantly more importance on their body image and sexuality (i.e. physical appearance, attractiveness to partner and self-evaluation of femininity and sexuality) than the mastectomy patients. After surgery, the former group tended to have a more negative mood on the shortened version of the Profile of Mood States than the latter group. Degree of self-efficacy had a marked influence on the patients’ mood after surgery. Conclusions: This study suggests the importance of discussing body image and sexuality that has tended to be disregarded in therapeutic decision-making situations in breast cancer patients in Japan. Self-efficacy is a crucial variable for improving mood after treatment.

We studied the relationship between segmental dynamics of matrix polymers and tracer diffusion of low mass compounds by the use of forced Rayleigh scattering and dielectric spectroscopy. Specifically poly(methyl acrylate), poly(ethyl acrylate) and poly( n -butyl acrylate) were used as the polymer matrices and six azobenzene derivatives with various substituents as the diffusant. The temperature dependence of the tracer diffusion coefficient D was measured on methylyellow (MY)/polyacrylate blends at the MY concentration of 1 wt%. The results indicate that the temperature dependence of D is weaker than the dielectric loss maximum frequencies f m for the α processes of the matrices. The effect of volume of the dye molecules on D was also investigated at 305 K. Comparison of the tracer diffusion coefficients among various dye/polymer systems indicates that log D in the same matrix decreases linearly with the molar volume of the dyes.

We report the dielectric study of dynamical heterogeneity in miscible polymer blends composed of four kinds of polyethers, i.e., poly(butylene oxide) (PBO), poly(isopropylglycidyl ether) (PiPGE), poly( n -butylglycidyl ether) (PnBGE), and poly( t -butylglycidyl ether) (PtBGE). All polyethers exhibit both the dielectric normal mode relaxations due to fluctuation of the end-to-end vector and the segmental mode due to local motions. In blends composed of polyethers, the loss curves for the segmental modes are unimodal but are asymmetrical when the composition becomes asymmetrical, namely 75/25 and 25/75. The asymmetrical loss curve indicates that the loss curve consists of the fast and slow modes. We have resolved the loss curves into the fast- and slow modes by curve fitting assuming that the segmental modes are composed of two e ″ curves. Thus we have estimated the separation of the fast and slow modes. The separation is approximately proportional to the difference of the glass transition temperatures of the components.

We studied viscoelastic and dielectric relaxation behavior of poly(vinyl acetate)/poly(ethylene oxide) (PVAc/PEO) blends in the miscible state. Especially for the viscoelastic measurements, we used highly asymmetric molecular weight MW combinations to examine the component dynamics separately. Time–temperature superposition principle did not hold since the two components have different shift factors (aT). We determined the aT of both components in the blends for the terminal relaxation modes. Concerning the dielectric relaxation, we observed single α-relaxation peak and found that the α-relaxation mainly reflected the segmental motion of PVAc in the blends. The dielectric and viscoelastic aT of the PVAc component showed almost the same temperature dependence compared at the same composition. From these aT data, we determined effective glass transition temperatures (Tg,eff) as a function of blend composition for both components. The results were compared with the literature data for a similar miscible blend, poly(methyl methacrylate) (PMMA)/PEO [T.R. Lutz, Y. He, M.D. Ediger, H. Cao, G.Lin, A.A. Jones, Macromolecules 36 (2003) 1724]. The Tg,eff’s of PEO in the two blend systems were almost the same at any compositions even though the blend partners have very different glass transition temperatures Tg’s: 311 K for PVAc and 405 K for PMMA. If we use the Lodge–McLeish (LM) model to explain the similar Tg,eff’s of PEO in both blends, the self-concentration of PEO should be dependent on the blend partner. This suggests the necessity to take into account the effect of the inter-molecular interaction in the LM model.

We investigated the dielectric normal mode relaxation in dilute and semidilute solutions of poly(propylene oxide)(PPO) and poly(butylene oxide)(PBO) in benzene which is a good solvent for PPO but a marginal solvent for PBO. The results indicate that the normal mode relaxation times τn in dilute solutions of PPO and PBO are proportional to [η]M in agreement with the Rouse-Zimm theory where [η] and M denotes the intrinsic viscosity and the molecular weight, respectively. With increasing concentration C, τn increases in proportion to C[η]. The dynamic crossover concentration between the dilute and semidilute regimes is about four times higher than the static crossover concentration C*. The relaxation strength Δe divided by C decreases with increasing concentration indicating that the mean square end-to-end distance decreases on account of the screening of the excluded volume effect. The concentration dependence of agrees approximately with the scaling theory.

We report dielectric relaxation behavior in blends of sodium montmorillonite particles (MM) with a series of polymers (i.e., polyisoprene (PI), poly(propylene glycol) (PPG), and poly(butylene oxide) (PBO)). These polymers are known to exhibit the dielectric normal mode due to the fluctuation of the end-to-end vector as well as the segmental mode due to local, segmental fluctuations. The data indicate that all blend systems exhibit an additional relaxation process at a temperature region below the glass transition temperature, T g , of the pure polymer component. The intensity of the new relaxation process increases with the content of MM and hence the relaxation process can be assigned to the segmental motion of the chains intercalated in the interlayers of MM. On the other hand, the relaxation time of the normal mode reflecting the fluctuation of the end-to-end vector is the same as the neat polymers but the intensity of the relaxation process increases due to enhancement of the internal electric field by MM.

We investigated the interfacial tension γ between poly(ethylene oxide) (PEO) and polystyrene (PS) focusing our attention on the dependence of γ on the molecular weight ( M ) of PEO and the surfactant effect of poly(ethylene oxide- b -styrene) diblock copolymer [P(EO- b -S)]. Measurements of γ were carried out by observing electric deformation of droplets of PEO suspended in bulk PS or in a concentrated solution of PS in dioctylphthalate (DOP). The results indicate that γ between PEO and PS is almost independent of M of PEO in the high molecular weight region, but exhibits a minimum around M = 500. Addition of 1 wt% of P(EO- b -S) to the PEO/PS system causes a decrease of γ due to the surfactant effect of the copolymer, but γ is almost independent of further addition of the copolymer. The decrement of the interfacial tension Δ γ increases with increasing molecular weight of P(EO- b -S).

Dynamic heterogeneity in miscible blends was investigated by the use of dielectric relaxation spectroscopy for blends composed of poly(vinylethylene) (PVE) and various polyethers, i.e., poly(butylene oxide) (PBO), poly(isopropyl glycidyl ether) (PiPGE), poly(n-butyl glycidyl ether) (PnBGE), and poly(tert-butyl glycidyl ether) (PtBGE). All polyethers are type AB polymers and exhibit both the dielectric normal- and segmental-mode relaxations, but PVE exhibits only the segmental relaxation. The data indicate that the loss curves for the segmental relaxation of PVE/PBO blends are bimodal in the range of PBO content less than 0.25. Since the dielectric relaxation strength of PBO is much higher than that of PVE, unimodal loss curves are seen at high PBO content. The effective glass transition temperatures for the fast and slow modes estimated with the Lodge−McLeish model agree fairly well with the temperatures at which segmental relaxation times become ca. 100 s. The ratio of the relaxation times for the normal...

We studied the dielectric relaxation behavior of low mass compounds (LMC) mixed in polystyrene (PS). Specifically, LMCs that are used are alkyl-cyanobenzene (nCBz, n = 0), alkyl-cyanobiphenyl (nCB, n = 0, 1, 3, 5, and 7), and alkyl-cyanoterphenyl (nCT, n = 5), where n represents the number of carbon atoms of the normal alkyl groups of the LMCs. Owing to a much larger dipole moment of the cyano group than that of PS, only motions of the LMCs were observed. In a blend of 5CT (5 wt %)/PS, single relaxation process designated as α was observed. On the other hand, in nCB (5 wt %)/PS, partially overlapped two relaxation processes (α and β) were observed in the order of decreasing temperature. We assigned the α process to cooperative motions between the LMC molecules and the PS segments, and the β process to spatially restricted motions of the LMC molecules in the glassy state. In 0CBz (8 wt %)/PS, the α and β processes were observed in distinct temperature regions and the intensity of the α peak was comparable to that of pure PS, indicating that the 0CBz molecules do not move cooperatively with the PS segments. We conclude the existence of two critical sizes (I and II) of LMC in relation to cooperativity: when an LMC molecule is smaller than the size-I, the motions of the LMCs and PS segments decouple each other, but above the size-I, they become cooperative. Above the size-II, the spatially restricted motion (β-process) of LMC does not occur. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 967–974, 2006

Dielectric measurements were carried out on undiluted poly(isopropyl glycidyl ether) (PiPGE), poly(n-butyl glycidyl ether) (PnBGE), and poly(tert-butyl glycidyl ether) (PtBGE) which have dipoles aligned parallel (type A) and perpendicular (type B) to the chain contour and the dipoles residing on the flexible side group (type C). These polyethers exhibited three dielectric relaxations designated as αn, αs, and β. The αn relaxation is due to the normal mode relaxation. The primary αs relaxation is assigned to local segmental motions coupled with rotation of the side group. The β relaxation can be assigned to both twisting motions of the main chain and libration of the side groups of a small amplitude. Independent full rotation of the side groups was not observed below Tg. The relaxation strengths and dipole moments associated with the αn, αs, and β processes have been estimated. In PiPGE and PtBGE, the temperature dependence of the loss maximum frequency fms for the αs relaxation was much steeper than that ...

Dielectric measurements were carried out on undiluted poly(butylene oxide) (PBO) with various molecular weights. The dielectric normal mode relaxation due to fluctuation of the end-to-end vector and the segmental relaxation due to local motions were observed. The relaxation time τn for the normal mode and τs for the segmental mode conformed to the Vogel−Fulcher equation, and the ratio of τn/τs did not depend on temperature. From the relaxation strengths for the normal and segmental modes, the parallel and perpendicular components of the dipole moment were determined. With the aid of the literature data of the end-to end distance, the dipole moment per unit contour length of PBO chains was also determined. It was found that the M dependence of τn changed around the characteristic molecular weight Mc (=6000), i.e., in the range of M Mc τn is proportional to M3.4. The relationship between the segmental dynamics and chain dynamics is discussed.

We report the dielectric properties of poly(styrene oxide)s (PSO) in bulk and concentrated solution states. Since the structure of PSO is asymmetric along the backbone, the repeat unit of PSO is expected to possess the non-zero component of the dipole moment pA parallel to the chain contour as well as the perpendicular component pB. The former and latter cause the dielectric normal mode and segmental mode relaxations, respectively. Contrary to the above mentioned expectation the temperature dependence of e″ exhibits only the primary (α) relaxation and weak secondary relaxation (β) in the glassy state. No loss peak due to the normal mode relaxation was observed in the frequency region expected from the viscoelastic terminal relaxation in bulk and toluene solutions. The dielectric behaviours of the α relaxation in the bulk state were analyzed in detail and the parameters of the Vogel–Fulcher and the Havriliak–Negami equations were determined. The Kirkwood correlation factor was determined to be 0.36. The 13C NMR spectra indicate that the present PSO samples contain about 2% head-to-head linkages. This cannot be the origin of the disappearance of the normal mode. We conclude that pA of PSO is too small to be detected. The pA calculated with molecular orbital methods supports this conclusion.

The specific heat capacities Cp of blends consisting of cis-polyisoprene (PI) and poly-(vinylethylene) (PVE) were measured in the temperature range from 80 to 320 K by using an adiabatic calorimeter. The configurational heat capacities C conf of blends around the glass transition temperature Tg have been determined by subtracting the vibrational heat capacities estimated with the Einstein and Debye theories. The C conf vs temperature T curves of the blends exhibit double sigmoidal increase at two glass transition temperatures T g1 and T g2 and can be resolved into two empirical sigmoidal curves. For each sigmoidal curve with the index j = 1 or 2, we have also determined the magnitude of the jump ACj and the broadness parameter Bj of the sigmoidal curves. The dielectric relaxation spectrum for the primary process of PI/PVE blends is known to be bimodal due to dynamical heterogeneity. The relationship between the bimodal dielectric segmental relaxation and the double glass transition processes has been analyzed.

We investigated the segmental and terminal relaxation dynamics of a well-characterized disordered diblock copolymer, poly(isoprene-b-vinyl ethylene) (PI-PVE), and miscible blends of polyisoprene (PI)/poly(vinyl ethylene) (PVE), using dielectric and viscoelastic spectroscopies. Generally, the concentration fluctuation (CF) amplitude of a disordered diblock copolymer is smaller than that of the miscible blend, especially in a length scale longer than the size of the whole block chain. To test whether the difference in the CF amplitudes causes the difference in the segmental relaxation spectra, we compared the shape of the dielectric loss curves between PI-PVE and PI/PVE with the same composition (PI/PVE ratio = 17:83). However, no appreciable difference was observed, indicating that the CF amplitudes in PI-PVE and PI/PVE are not so different in the length scale of the segmental motions. We also examined the effect of distinct friction coefficients of the PI and PVE chains on the terminal relaxation dynamics by comparisons of the viscoelastic and dielectric normal mode relaxations in PI-PVE. The former probes the whole chain motion and the latter probes motions of the PI block. Shift factors (aT) for the viscoelastic and dielectric relaxations were compared. The dielectric normal mode aT was found to have weaker temperature dependence than the viscoelastic aT, which indicates that the friction for the PI block chain is lower than the average friction for the PI-PVE chain. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 4084–4094, 2004

Phase behavior and dynamics in blends of a liquid crystal 4-cyano-4‘-n-pentylbiphenyl (5CB) and polystyrene(PS) were investigated by using dielectric spectroscopy. The blends exhibit phase separation of a UCST type. Below the phase-separation temperature, the blends separate into the isotropic PS-rich and 5CB-rich phases. With decreasing temperature the 5CB-rich phase transforms into the nematic liquid crystalline state and subsequently into the regular crystalline states. The nematic phase supercools about 30 K below the nematic-to-crystal transition point TNC. Optical micrographs of blends indicate that spherical 5CB-rich domains are dispersed in the matrix of PS-rich phase even at the 5CB content of 80%. A strong dielectric relaxation due to rotation of the 5CB molecules in the isotropic PS-rich phase has been termed α. The α process exhibits complex temperature dependence due to the changes in the composition and morphology with temperature. Although the 5CB-rich phase crystallizes mostly at low tempe...

We investigated the dielectric normal mode relaxation on diblock copolymers poly(isoprene-block-butadiene) (I-B) with several polyisoprene (PI)/polybutadiene (PB) compositions. Through the dielectric measurements on I-B, we can obtain information about the dynamics of the PI subchain since the PI block is labeled with type-A dipole but PB is not. At the same time, we carried out viscoelastic measurements on the same I-B samples to obtain information of the whole chain motion, especially the longest relaxation times and the plateau moduli. From these viscoelastic and dielectric data, we can directly compare the relaxation spectra of subchains with those predicted by the tube model. From such comparison, we have found that the end part of the chain relaxes faster than the theoretical prediction suggesting extra relaxation mechanisms other than reptation in the dynamics of chain ends.

We investigated the dielectric relaxation in blends of 4-n-pentyl-4’-cyanobiphenyl (5CB) and polystyrene (PS) in order to examine the size effect of low mass molecules on the cooperativity of local dynamics. To obtain the dielectric data in the isotropic state, the phase diagram was produced. The temperature (T) dependence of the dielectric loss factor e” of PS/5CB blends containing 20 to 30 wt% of 5CB exhibited a bimodal peak near the calorimetric glass transition temperature Tg. The bimodal peak was resolved into two peaks termed α and β. The α process locates above Tg and can be assigned to cooperative motions of the PS segments and the 5CB molecules. The β process is responsible to independent reorientation of the 5CB molecules in the glassy PS matrix. The α and β loss peaks tend to merge with increasing T. This behavior contrasts to the dielectric behavior of the PS/toluene system which exhibits loss peaks due to segmental motions of PS and rotation of the toluene molecules in well separated temperature regions. The toluene molecule has a size of ca. 1/3 of the 5CB molecule and does not move cooperatively with PS but the 5CB molecule does. From the intensity of the α and β peaks, the fraction of the 5CB molecules moving cooperatively with PS has been estimated to be 0.25 and 0.63 for the blends containing 30 and 20 wt% of 5CB, respectively.

We investigated the thermal and dielectric behavior of blends consisting of semicrystalline poly(l-lactic acid) (L-87) and amorphous poly(dl-lactic acid) (DL-74 and DL-7). Two series of blends L-87/DL-74 coded as B1 and L-87/DL-7 coded as B2 were used where the code number indicates molecular weight Mw in kg/mol. The DSC thermograms of quenched blends exhibited a single glass transition at about 326 K followed by the exothermic peak due to crystallization of L-87. The relatively sharp glass transition indicates that both components are miscible in the molten state. The degree of crystallinity χ was determined from the heat of fusion. Three dielectric loss peaks were observed for B2. They are termed αn, αs, and β as reported previously [Macromolecules 2003, 36, 210] and are assigned to the normal mode relaxation of DL-PLA dissolved in the amorphous region, the segmental mode process, and local twisting motions of the main chains, respectively. The dielectric relaxation time for the αn relaxation was almost...

Dielectric study was performed on the polyisoprene (PI)/poly(vinyl ethylene) (PVE) miscible blends. We observed the end-to-end vector fluctuation dynamics (normal mode) of PI as well as the two α-relaxation processes corresponding to the segmental motions of PVE and PI. Among these three relaxation modes, the normal mode relaxation behavior was examined in detail. Since this relaxation reflects the dynamics of the length corresponding to the end-to-end distance of PI chain, comparison of the relaxation times for the normal mode and α-processes gives the information about the length scale of the two α-relaxation modes. We estimated the relevant length scales for the segmental motions in the blend and compared them with a single cooperative volume model and a dual length scale model. As a result, the latter model was found to describe better the features of the segmental dynamics in PI/PVE blends.

The effect of the solvent quality on local concentration fluctuation was studied for concentrated solutions of polystyrene (PS) in toluene (Tol), ethylbenzene (EtBz), n-propylbenzene (PrBz), and n-butylbenzene (BuBz) by using dielectric spectroscopy. The exponents of the Mark−Houwink−Sakurada equation of those solutions indicate that the solvent quality deteriorates in the order of Tol, EtBz, PrBz, and BuBz. Three dielectric relaxations designated as α, β, and γ are observed in the temperature dependence curves of the dielectric loss in the order of decreasing temperature. According to our previous study on PS/Tol solution, the α, β, and γ relaxations have been assigned to local segmental motions of PS, rotation of the solvent molecules, and the secondary relaxation in the glassy state, respectively. The half-width of the dielectric loss curve Λα for the α relaxation of PS/Tol solutions is independent of temperature, but the values of Λα for solutions in EtBz, PrBz, and BuBz increase with decreasing tempe...

Fractionated samples of d , l -poly(lactic acid) (PLA) were prepared and the dielectric normal mode relaxation was studied for dilute and semi-dilute solutions of the PLA in a good solvent benzene. Results indicate that in the dilute regime the normal mode relaxation time is proportional to [η]Mw in agreement with the Rouse–Zimm theory, where [η] and Mw denote the intrinsic viscosity and weight average molecular weight, respectively. The dielectric relaxation strength which is proportional to the mean square end-to-end distance 〈r2〉 increases with increasing Mw with the power of 2ν, where ν is the excluded volume parameter determined from [η]. The relaxation time in the semi-dilute regime increases with increasing concentration C due to increases of the entanglement density and the friction coefficient. The relaxation time corrected to the iso-friction state agrees approximately with the dynamic scaling theories. The relaxation strength decreases with increasing concentration indicating that 〈r2〉 decreases on account of the screening of the excluded volume effect. The concentration dependence of 〈r2〉 agrees approximately with the scaling theory proposed by Daoud and Jannink.

Relationship between segmental relaxation and normal-mode relaxation has been studied for molten poly(butylene oxide)s having various molecular weights by broadband dielectric spectroscopy over a wide temperature (T) range. We found that T dependence of the segmental relaxation time, τs, was weaker than the normal mode time, τn, at high T(>250 K ∼ Tg + 50 K), and the τn/τs ratio systematically decreased with increasing temperature. This high temperature complexity, whose mechanism has not been discussed in detail so far, was quantitatively explained by assuming the two step processes: local conformation change of polymers (elementary process) occurs first, and then the motion of a segment unit (second process) occurs. It was also found that the elementary process was strongly correlated with the experimentally observed β-relaxation.

We report the dielectric and viscoelastic relaxations in undiluted amorphous poly(d,l-lactic acid) (PLA). Three dielectric relaxations designated as αn, αs, and β are observed in order of decreasing temperature. The relaxation time for the αn relaxation increases with increasing molecular weight and is assigned to the normal mode relaxation due to the component of dipole vector aligned in the direction parallel to the chain contour. The αs relaxation is observed about 30 K above the glass transition temperature Tg (= 310 K) and is assigned to the local segmental mode due to the transverse component of the monomeric dipoles. The β relaxation is seen in the glassy state and is assigned to the secondary relaxation. From the relaxation strengths for the αn, αs, and β relaxations, the effective dipole moments for those relaxation processes are determined and compared with the parallel and transverse components of the dipole moment calculated theoretically with the semiempirical molecular orbital methods. The d...

Dielectric relaxation of the segmental mode in concentrated solutions of poly(vinyl acetate) (PVAc) in toluene (Tol) and in 1-methylnaphthalene (MN) and those of poly(vinyl octanoate) (PVOc) in Tol were studied. It was found that the distributions of relaxation times in concentrated solutions were much broader than those in dilute solution and in the undiluted bulk polymer. The broad spectra were ascribed to local heterogeneities. The half width Λ increased with decreasing temperature and this behavior was explained by assuming that Λ is proportional to the amplitude of the local concentration fluctuation Δφ times the slope of the φ dependence curve of the average relaxation time τ . This assumption leads to a linear relationship between Λ and Δφ /( T − T 0 ) 2 where T 0 is the Vogel critical temperature. Using this relation, we attempted to estimate Δφ .

We report the dielectric relaxation in a ternary system in which a trace amount of poly(n-hexyl isocyanate) (PHIC) is dissolved in concentrated toluene solutions of polybutadiene (PB). The dielectric response is due to the rod-like PHIC molecules having high dipole moment along its chain contour. Solutions of PB form entanglement networks which retard the reorientation of the PHIC molecules. With increasing concentration (CPB) of PB from 0 to 40 wt% the relaxation behaviour changed at a crossover concentration CPB+. In the range below CPB+, the relaxation time τ for reorientation of the PHIC molecules increased on account of the effect of entanglement. However above CPB+, τ decreased and at the same time the relaxation strength decreased with increasing CPB. The crossover concentration CPB+ depended on the molecular weight M of the PHIC, i.e. C+PB=0.13 at M=29,000, and CPB+=0.25 at M=20,000. The decrease of the relaxation strength can be attributed to the reduction of the effective dipole moment due to the restriction of motions of the PHIC chains in entanglement networks of PB chains.

We investigated ultrasonic attenuation, dynamic Young's modulus, Izod impact strength, and dielectric relaxation of acrylonitrile–butadiene–styrene composite polymers (ABS) in which styrene-co-butadiene rubber particles are dispersed in styrene-co-acrylonitrile random copolymer. High ultrasonic attenuation was observed around 240 K and the intensity of attenuation increased with increasing rubber content. Temperature dependence curves of dielectric loss in the frequency range from 12 Hz to 200 kHz and temperature range from 80 to 420 K exhibited four relaxation processes designated as the α, β′, β, and γ. From the relaxation map produced for the mechanical and dielectric relaxations, the ultrasonic absorption was attributed to the β and β′ processes. It was deduced that inter-grain thermoelastic process, also contribute to the ultrasonic attenuation. Correlation was found between the ultrasonic absorption and the Izod impact strength indicating that the high impact strength of ABS is partly due to the effective absorption of impact energy through those relaxation processes.

Dielectric measurements were carried out for linear and star-shaped poly(propylene glycol)s (PPGs) of different molecular weights (M). A small loss peak due to the normal mode relaxation was observed on the low-frequency side of the main loss peak. Two peaks were resolved and the normal mode relaxation time τn, the distribution of relaxation times and relaxation strength were examined. The effect of OH groups attached at the chain ends on the normal mode relaxation was also investigated by using PPG samples whose end groups were substituted by acetyl groups. The results indicate that τn is proportional to M2 in accordance with the Rouse theory. The mode distribution of star-shaped PPGs is slightly broader than that of linear PPGs. The effect of hydrogen bonding between the OH groups on the normal mode relaxation time is negligibly small.